Anuraag Reddy

AIESEC India

This conversation is closed.

Why evolution could never solve aging?

Maybe aging is an essential mechanism to clear out the old and make way for the new like cells within a body?

Maybe every form of life is already close to the upper limit of life expectancy?

Maybe aging is in the nature of carbon based life and metabolism?

Maybe we genetically sacrifice our longevity to survive the stresses of competition.

Emerging Questions:
Is it that our metabolic processes are over-compensated for dominance in their sexual prime which prove detrimental for longevity?

Is it that genes leading to different lifespans are mixed indefinitely in nature that it was never possible to select for it?

Isn't an organism with a longer span of mating at an advantage?

My hypothesis:
In the absence of change in ones environment, or competitive stresses an organism would eventually adapt itself to survive longer.

If every organism is a product of evolution then there must of course be underlying mechanisms within itself to aid such an adaptive process.

Under the influence of adaptive pressure, it would encourage mutation or variations in order create successful variations and also increase the number of life-cycles and so reducing the lifespan.

Under the influence of competitive stress, the dominance would lead to reproductive success and not the span of mating during ones lifespan.

In the absence of change in ones environment leading to adaptive pressure, or competitive stresses from rivals to prove dominance. Species would evolve longer lifespans.

Just a Theory though! But it would predict that

Lifespans of living fossils which have undergone little change in time should be greater than their relatives which have recently evolved.

Life having evolved on geographically isolated places far from intense competitive pressures should have greater lifespans.

Living things higher up in the food-chain or with few natural enemies should have greater lifespans.

Life span in pair bonding species should be higher than tournament species.

  • Nov 20 2011: I must say, first - I don't know why we need to view aging as a problem. "The problem of aging". I see no problem with old age and eventual death. I'm very interested in the reason for a line of questioning like this.

    At any rate, evolution and aging have, in my view, very little to do with the other. Natural selection no longer comes into play after child-bearing age. As much as I hate to personify it, evolution doesn't really care about old people. According to natural selection and the survival of a species it doesn't matter in the least if you survive after rearing your offspring.

    It's against a population's best interest to prolong life past a certain point, most especially if child-bearing years are lengthened. The vast and overwhelming majority of animals on this planet will make offspring if age and health allow. The scenario that's painted by older creatures being able to continue to give birth is one of, eventually, a nearly infinite spring of life into a world of very finite resources, and eventually that little experiment would lead towards a stripping of natural resources, hunger, crowding, etc.

    Aging and eventual death keeps the genetic pool fresh and ensures a homeostatic planet with balanced resources. Prolonged life or immortality eventually means an overburdened planet.
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      Nov 20 2011: I like your explanation, considering a majority of recent opinions on this thread cite that aging and eventual death are required to maintain a balance of resources.
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      Nov 20 2011: I basically agree with George's reply, but will point out that post-reproductive (older) individuals can still make a considerable contribution to the survival of the group or of individuals within the group, and as such they can have significant impact on the evolutionary course of the group and the species. It may be correct to say that when the older individuals reach a point where they are more burden than help to the group, then they no longer impact the group's evolutionary course. But keep in mind that all of a species' characteristics, including their behavior - such as their degree of caring for older members, play a part in the evolutionary game.
      The initial question of why debilitating aging occurs is still interesting. We know that during our lifetimes mutations occur in our DNA, both through copying errors whenever our cells divide, and through the ionizing effects from various sources of radiation. Preventing such mutations completely would have been metabolically costly and might not have been possible for complex organisms. As it is, there are many redundancies in our bodies that minimize the effect of mutations for many years, and these are certainly the result of evolution operating to give us the long length of life that we have. An interesting study is of "aging" in simpler systems like bacteria, which are very resistant to debilitating mutations, yet are highly adaptable to changing conditions. A puzzling paradox.
    • Nov 22 2011: Your explanation unfortunately assumes that which is sets out to explain, i.e., that at some stage an organism's "child-bearing age" ends.

      That an organism's child-bearing age usually does end is manifest, and so universal in our experience that it seems natural. But that it does is an aspect, or perhaps a phase, of aging, the phenomenon we seek to explain.
      • Nov 22 2011: I'm afraid that I haven't unfortunately assumed anything, if the condition of a limited child-bearing age is manifest and universal in our experience. There's no reason to believe that something like menopause is anything but natural, seeing as how we have extremely limited examples of evidence to the contrary. Menopause and aging go hand in hand, certainly, but it's wildly illogical to assume that either of these things are unnatural.

        The simple fact is that the key to successful life on this planet is adaptability. Without the ability to adapt to changing conditions, an organism will eventually fall prey to the tumultuous environment that we all live in. If an organism doesn't eventually stop giving birth, then it continues to pass its own unchanging genetic structure on through the world, and evolution slows down immeasurably and becomes stunted.

        Aging and eventual death are a part of this world, and they are the mechanisms that allow for growth in the species overall.
        • Nov 22 2011: Limited child-bearing age, menopause, etc. are the phenomena that we are trying to explain. They can't be the reason for themselves. Supposing that they exist to explain why they exist is a circular argument.

          Your second argument (like that of several explanations above) is that if there were no aging a catastrophe would eventually occur (or would have occurred), specifically, that if organisms did not age and die then evolution would slow down and life would fail to adapt. That's not a workable explanation, because evolution doesn't have any foresight. To explain why a biological phenomenon evolved you need to describe the mechanism by which organisms that had the causative mutation flourished and proliferated in competition with the rival alleles. Preventing a catastrophe in the future is not a way to survive and reproduce in the present.

          To explain the evolution of senesence you have to explain a mechanism by which mutations that cause senescence proliferated when they were new and rare. Making room for a new generation is not such a mechanism, because most of the benefits to fall to the more numerous offspring of non-aging rivals. That isn't a competitive benefit to the mutants. Preventing a catastrophe to either the species, the ecosystem, or life itself isn't an explanation either, in the first place because saving the world, the region, or the species is not a competitive advantage to the mutants of their rivals, and in the second place because there is no mechanism for a possible catastrophe in the future to either prevent specific mutations or to save the lives and increase the progeny of specific mutants or to suppress their rivals in the present, Evolution does not provide protection against extinction, which is clear when you consider that most species that ever evolved have gone extinct.
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          Nov 23 2011: This looks like an evolutionary dead-end, I can't reply to Brett but Go Evill! lol

          I side with you, as evolution doesn't have a foresight, nothing evolves for the good of the species, it is individual fitness that matters and there must be a reason for the development of senescence and its efficacy as a trait.

          Males can continue to mate until death, the child bearing/rearing hypothesis only applies to human females.
    • Nov 23 2011: "Natural selection no longer comes into play after child-bearing age. (...) According to natural selection and the survival of a species it doesn't matter in the least if you survive after rearing your offspring."

      Hey, which species are you talking about? Our own or all the others -- or are you putting all in the same basket?

      As far as our species is concerned, do you mean that its perennity is granted by the sole production of offspring, as with animals? How about inventions, technology, science, infrastructures -- all those "children" born out of the human brain?

      It seems to me you're in great need of some enlightenment -- which you might find in my reply to Christopher Henningsen in this discussion.

      Comment on Brett Evil's reply to your comment:

      Both of you (and most of the commentors in this discussion) are talking about limited child-bearing age as if natural selection had led to prevent the transmission of genes coding for exceptional longevity -- whereas in actual fact evolution has preserved the option of selecting these genes by not limiting the age of male fertility (as far as I know, for us humans)!
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    Nov 25 2011: Aging has been solved. . . . . by Death.
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    Nov 25 2011: Why aren't ant's or bee's being researched? They are clearly masters at manipulating age when it comes to queens. I just watch this interesting talk by Deborah Gordon on digs ants and the queen ant live 15 times longer than other normal ants and it's not because of a special DNA. They use the same ant DNA.
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      Nov 25 2011: If you mean "average lifespan" is makes sense that queen ant lives longer than the others ants which are more susceptible to disease, get killed, have worst food, work more, etc. all kind of environmental and behavioral factors.

      this is the tedtalk about it: http://www.ted.com/talks/deborah_gordon_digs_ants.html
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        Nov 25 2011: I don't think it's just average life spans. As I understand it the queens life longer by default.
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          Nov 25 2011: If you meant "Maximum life span" it has to be something related to DNA. From what I understand yes they share a common DNA while they are at a larva stage but the level of care and nourishment the larvae receive will determine their eventual adult form.

          "Analysis of ... new ant genomes suggests that chemical modification of certain sections of DNA could be responsible for the differential development of queens and workers. As an ant larva develops, DNA methylation ... may switch off the genes that control reproductive capacity and wing growth." AND I WOULD ADD IT ALSO SWITCH THE RATE OF AGING.

          SOURCE: -Newly Decoded Ant Genomes Provide Clues On Ant Social Life, Pest Control-
          http://www.sciencedaily.com/releases/2011/01/110131153244.htm
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        Nov 27 2011: Well stated comments about the queens there, Adrian. It is what the future 'queen' is fed, in some species that 'grow' her to be a queen in the first place.

        So in 'essence' it is what she eats, the enzymes in the food (and other properties) that affect her genome.

        Also, in regards to human evolution-the topic on this forum question- there are some who theorize that 'food' may have contributed to our own evolution, so I understand.

        Interesting thought, yeah?

        Maybe the related 'humanlike' species who eventually formed us started to consume a new diet that introduced different enzymes, vitamins etc. that helped to shape our own genome?

        Anyway, totally unrelated-unrelated. I think we are all queen bees who can lead or follow-humans that is.

        And food (and other phenomena) is important to not only our own brain function but the shaping of our progeny (ie look up stuff in epi-gentics). Just a thought out there.
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      Nov 27 2011: On a related note-There is a jelly fish that has 'infinite' life. Yep. It lives forever if it can keep from disease and being killed. It just renews it's life by "reverting to its polyp state." Yeah, amazing, right? I love jelly fish. This one is really pretty too but there are so many beautiful ones.

      Article about these little guys:

      http://green.yahoo.com/blog/guest_bloggers/26/the-world-s-only-immortal-animal.html
    • Nov 27 2011: A more philosophical approach of queen bees' longevity may yield some interesting findings considering that drones are left to starve after one of them has fecundated the queen -- which reminds us that bees are living in matriarchal societies.

      By analogy, patriarchal societies might feature an exceptionally long-living king male dedicated to churn out "the 'children' born out of the human brain", as explained in my first comment, hinting at the "unchallengeable leadership of the very one who willl be living longest" predicted in the same comment.

      Fortunately, money can be used to virtually extend the remaining life-span by packing more years into it through subcontracting the more time-consuming tasks involved with the bearing and rearing of major inventions, so as to get these tasks done in parallel time.

      Now, since money can help densify your life, the question of how to achieve exceptional longevity becomes that of whoses life deserves being densified. The first answer coming to my mind is that society should stop spreading big money randomly through lotteries, and instead try to get the masses financing the densification of the remaining years of, say, an outstanding elderly inventor... with a sample of his (my) revolutionary aircraft as the jackpot for the winner!

      Yet, alas, if this kind of lottery could get me to sell my invention to, say, Boeing, they'd probably kill it in order to preserve the long-term success of the current assets of the Boeing-organism...
  • Nov 22 2011: The best explanation I ever saw for this question was mostly mathematical. I'll try to summarize it here, but I may mangle it a bit.

    The thing is, human population has been expanding for as long as anyone can remember, but established species always have stable populations. In an expanding population, having more children indefinitely would be beneficial, but in a steady one, each mating pair can only have a finite number of offspring. If a species grows for too long, it presumably destroys its niche, so there needs to be an upper limit on how many offspring a species can typically have, depending on how many die before mating age. This is a question not of individual fitness but of species wide fitness

    If we accept this premise, it's fairly easy to see why death is beneficial to the individual. Imagine a species where the typical mating pair can produce 3 children on average, can reproduce for three generations, and reaches sexual maturity in one. A pair that has 3 children in its first generation will have nine times as many descendants by the third generation as one that has 3 children in the third generation. Evolutionarily, it's better to reproduce early rather than late (unless the population is shrinking, but never mind that now). 'Natural Causes' encourage early reproduction.

    I don't remember the math, but the paper I read explained to my satisfaction at the time that given the above conditions (which admittedly don't apply to humans since we don't have a stable population yet) there would always be an optimum age for an individual of a species. the exact age would depend on various factors, but it would always be finite.

    I really haven't done the theory justice and unfortunately don't remember the name of the paper, but I thought it was interesting enough to share anyway. Hope someone enjoyed the read!
    • Nov 23 2011: "A pair that has 3 children in its first generation will have nine times as many descendants by the third generation as one that has 3 children in the third generation. Evolutionarily, it's better to reproduce early rather than late,"

      In a more generic style your first phrase reads: the comparative growth rate of two populations will be higher in the population where the women's average child-bearing age is lower.

      As to the higher growth rate through early reproduction being an evolutionary advantage, I doubt it always is -- especially since human intelligence has entered the scene resulting in democracy based on the predominance of the majority's will.

      Now, since when should the reason of the majority be the better one, knowing that wisdom is a rather rare virtue among humans? That's probably what Churchill meant with his famous statement about democracy being the worst system of government, except all others...

      How come that the change of paradigm with the emergence of human intelligence versus the previous state of unconscious animal intelligence has been paid so little attention in this discussion?

      I invite you to reflect upon the hypothesis that while outnumbering other species may constitute an advantage in the vegatal and animal worlds, it may well have become a handicap in the human world where information, as based on unlimited accumulation, is taking the lead on the genetic code based on the relentless yet imperfect reproduction of a finite set of elements.

      And by accumulation I don't mean piling up books, but the virtually unlimited storage capacity of the human brain -- not by the sheer number of informations, but by the ever more complex correlations it can establish during a lifetime; an advantage which is likely to be developed by those who live longer, and ultimatley even to grant unchallengeable leadership to the very one who willl be living longest -- if not, at last, to an omniscient computer.
      • Nov 23 2011: An excellent hypothesis concerning future human evolution, but I don't fully understand your point about outnumbering other animals being a handicap to humans. I would think that nearly all human evolution has been an arms race against either germs or other humans, with other races playing an increasingly less competitive role. I don't think you are wrong, the current trend towards smaller families is an excellent indication that your idea has merit, but I don't understand your logic. Would you be willing to elaborate on this idea?

        On another note, I think a distinction must be made between memetic and genetic evolution. Though memetic evolution is becoming more and more fashionable as an area of study, there is far less history to study- the oldest known surviving texts are only a few thousand years old, and oral traditions mutate so quickly that it's difficult to study their history at all. Genetic history however is millions of years old with excellently preserved examples, and still seems to have many mysteries. I wouldn't sell it short !-)
        • Nov 25 2011: "I don't fully understand your point about outnumbering other animals being a handicap to humans."

          Sorry, the last part of my hypothesis should read: "while outnumbering other species may constitute an advantage in the vegetal and animal worlds, outnumbering other ethnic groups may well have become a handicap in the human world."

          An example of this questioning is whether China's success is based on outnumbering other nations or on the one-child-per-couple policy -- I for one would favor the second guess.


          As to outnumbering being a problem within the human species, here's another example: according to my very personal analysis of the evolution of communism, the Soviet rulers failed because they did not calculate their quinquennal plans by computer -- instead, they left this task to an army of human calculators who ended up outnumbering the decision makers of the real economy, when they became a state within the state, compromizing central governance.

          The Chinese communist rulers still calculate quinquennal plans, but since they do it by computer they manage to remain a small crew in charge of the nation's destiny.

          Small is purposeful!

          However, there seems to be a moral issue related to predation: predators carry genes coding for keeping their numbers small versus the lifestocks they prey on, in order not to reach a statistically significant ratio beyond which natural selection among their preys would start to work against them.

          But does a small number of rulers mean they have to be predators? And does a small minority have to consist of rulers at all?

          Here's a clue: there are much less pollinizing insects than plants offering nectar -- and, in Nature, symbiosis is largely predominant over predation.

          Predation is an epiphenomenon on the decline in both the animal and human worlds -- symbiosis is our future!

          Mainstream symbiosis is about sedentarity teaming with mobility -- and most of the mobile symbiots are flying animals!

          Our future is in the airspace
      • Nov 26 2011: Regarding the amount of complex passageways one can establish in a ever-maturing brain-I believe the number is limited due to the fact that if too many passageways are formed and intertwined, there is simply not enough space for them to avoid clashing, creating a responding amount of chaos. For the passageways, or coorelations to remain efficient and become more so, it would take a significant amount of energy, which, as one ages, is very hard to sustain without damaging other areas needed to survive.

        I am by no means an expert on this subject, but to me it seems this is the reason functions of the brain tend to almost "rust" in a sense, in most cases the apparent change affecting memory and physiological functioning.

        To comment on a special I saw - I believe it was the Discovery channel or something and involved Adam from Mythbusters (awesome, I know)- it would make sense that at some point, we would have to find a way to "replace" our body parts, but I honestly don't know how feasible it would be to actually repair a brain without disrupting the circuitry.
  • Nov 22 2011: Peter Medawar suggested an explanation for aging in "An Unsolved Problem in Biology" [1952], which, as refined by G.C. Williams in 'Pleiotropy, natural selection, and the evolution of senescence' [1957], seems adequate and convincing as a core explanation.

    First, observe that many genes have more than one apparent effect (a phenomenon called "pleiotropy"), and that some genes may have one effect that promote survival, reproduction, and the successful raising of offspring and another effect that inhibits it. Whether a gene proliferates over evolutionary time is the result of its average net effect in a particular environment. Second, observe that an organism's genes are expressed differently at different times in its life-cycle. Consider, for example, that a caterpillar and the butterfly it develops into have the same genes.

    Now think of a gene like that for Huntingdon's Chorea in humans, which increases fecundity in young people but causes disability and death in middle age. It should be fairly obvious that such a gene can produce an increase in the rate of its proliferation by trading off length of reproduction for rate of reproduction. In conditions where such genes flourish there is an evolutionary pressure in favour of aging.

    We ought to expect multiple instances of such genes to spread through any gene-pool. Once they are established there is a selective pressure that favours genes that adapt the organism to senescence, such as the genes that are supposed to switch women's efforts from bearing children to raising grandchildren after menopause. Indeed, senescence in animals is so ubiquitous that we must suspect that it is a primitive feature, and that major aspects of ontogeny are adapted to producing a mortal organism, that at least some of the processes of senescence consist of processes of development and growth continued past the point at which other processes dictated senility. See Hamilton, W.D. (1966) 'The moulding of senescence by natural selection'.
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      Nov 23 2011: Hey Brett!
      I believe this post has received less credit than it deserves, so I would like to bring more attention to it. I will read further about "Pleiotropy."

      It is possible that organisms must be trading off longevity to be more competitive in their sexual prime, so they could leave more copies of themselves. All traits were selected for having their advantage, but later in the course of evolution when such traits become more common in the population, competition drove such traits to be expressed around the time of mating, even if it was self-mutilating in the long run.

      Like they say it is better to burst like a cracker than burn like a candle. Reproductive impact mattered more.
  • Nov 21 2011: This is neat. We just were talking about this in one of my forestry classes. As some trees can live very very long lives. Some, it seems, live forever. The prime example is bristlecone pine ( I think Pinus longaeva D. Bailey). It lives forever and hypothesized that some individuals have cells with DNA that have "forgotten" the death or shutting down activation. It seems that the trees cells just live forever and ever. The downfall of this tree is it can only grow in one place with such a evolved trait as it is very in-efficient and cannot compete.
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      Nov 22 2011: whoa! That is interesting... A living fossil that doesnot compete.
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    Nov 17 2011: That question gave me a lot of time to think these two days ago.....

    I have just seen one talk about that.

    http://www.ted.com/talks/aubrey_de_grey_says_we_can_avoid_aging.html

    He says: "Aging is not a product of selection, evolution; aging is a producto of evolutionary neglect. We have aging because it's hard work not to have aging".

    Please see it; however that question is eating up my head all the time.

    Maybe aging is part of nature, maybe living matter always ages.... it doesn't care how long it takes, but it always happens.
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    Nov 17 2011: My guess about this is that every organism's life is as short as its genes can afford.

    Humans live longer than chimps after menopause, since babies require grandparents as well as parents. (Menopause is 3 years before death in chimps = you die knowing that the last child has been carried to autonomy... Menopause is about 20 years before death in humans = you die knowing that the last child's child has been babysat)
    Longevity has a cost, you know, for the genes. The shorter the life the better. Why is that?

    Well, having offspring means that your genes are now competing for food and sex, and one can understand how the genes would benefit from the non-reproducing organism to be dead. I read of some fish that ages immediately after reproduction, an hormonal booby trap.
    Remember that your genes are in all your relatives, unequally distributed of course. But cousins, siblings and children share your genes and if you can't provide their survival into the next generation, let them take care of it. If there's nothing you can do to help anymore, then get out of the picture ; more of everything for everyone.

    Makes me think about our old people. Once our kids have been babysat by our parents, the best thing they can do to help is to die, isn't it?

    So what lives forever is not subject to natural selection, since no replicator has any advantage of lingering once it's made a copy of itself. Especially if such replacing produces variation that might be beneficial.

    Until recently, no form of life has emerged from something else than natural/sexual selection, so immortal living organisms cannot have evolved.
    In fact, immortal living organisms can only be created by ... I hate to say this... intelligent design!
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      Nov 18 2011: Isn't an organism with a longer life and a longer sexual prime at an advantage? Or maybe breeding after a certain age would mean passing on damaged genes which would prove detrimental on the long run?
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        Nov 18 2011: It works this way if there are no or few factors which introduce evolutionary pressure. Why do turtles live so long? They have hardly any enemies so the longer their lifespan the more offspring they can produce - selection for longevity.
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        Nov 18 2011: - Isn't an organism with a longer life and a longer sexual prime at an advantage?

        I suppose it has something to do with sexual prime overlap. I your prime lasts ages, then it will largly overlap with your children's prime. So children whose parents leave the scene are likely to reproduce more since there is less competition, and thus the genes encoding this trait are selected.

        But there are more possible explanations, depending on the species. One of these might have to do with the number of offspring. Sometimes it may be an advantage to have few offspring and thus have more energy available to ensure their safety. Other organisms such as trees have tremendously long sexual primes and produces hudge quantities of seeds, because of the low cost of offspring in the vegetal kingdom. Thus, yeah, trees would benefit from near immortality and near infinite procreation, in this sense.
        But one thing about trees, though : two generations are never rivals over sunlight or minerals, since
        a seed that has fallen at the base of it's shadowing parent is just about doomed. So a succesful descendant is one that has landed far away, and it can only grow where it's not bothering its procreator.

        All this is just deduction, not proper scientific information, so someone who knows the first thing about biology might rake me over the coals.
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      Nov 18 2011: Does that mean my kids are being kind to me by not having kids yet?
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        Nov 18 2011: Perhaps they need their mother a little longer before she turns her attention to grandchildren (since concentration of energy on grandkids is a hell of a lot more fruitful at this point, evolutionnary speaking of course).

        Or perhaps there's no lady out there as great as mom...
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          Nov 19 2011: Gerald, for a hairless creature you are very sweet.
  • Dec 6 2011: A beautiful principle of evolution is that its designs only have to work well enough - well enough for the genes of an individual to propagate to successive generations. Perhaps the sheer evolutionary costliness of immortality for a mammal has proven too much and a higher metabolism was favored as a more engaged nervous system could live long enough to sufficiently reproduce.

    Although the mechanisms responsible for aging are not exactly known, it is clear that it's a complex matter involving many different biochemical factors. To overcome such a feat by natural selection may simply be too improbable to ever occur or it may need not ever occur because of easier solutions (higher metabolism = shorter life, but more strength, speed, intelligence for more reproduction = more genes in the gene pool to favor shorter life).

    But, on the other hand, evolution has stumbled upon a species capable of redesigning its very own nature with the potential of reaching conscious immortality. So maybe the question is "When will evolution solve the problem of aging?"
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      Dec 8 2011: You seem to be in favor of the Antagonistic pleiotropy theory: Late-acting deleterious genes may even be favored by selection and be actively accumulated in populations if they have any beneficial effects early in life.

      A likely possibility and well arrived at. :)
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    Dec 1 2011: Not all organisms age.

    Dieing is a selection step within the process of evolution. If you would implement any of the evolutionary algorithms you would understand it better. http://en.wikipedia.org/wiki/Evolutionary_algorithm

    Human race managed to escape evolutionary pressure by not of adapting, instead we are changing our environment (irrigation, shelter, heating, clothing, sanitation etc.).

    That being said, I still wish I would not have to die someday...
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    Nov 22 2011: Actually, aging is a more recent feature of evolution: If you look at simple one celled organisms, there are quite a lot of them who don't age at all (and can live very very very long).
    Their metabolism is rather slow... (and indeed, their environment is similar for thousands of years)

    Metabolism tends to cause damage (as energy transformation can be a violent process, suite difficult to control)

    Once you have sexual reproduction, it does not matter what happens with the parents once reproduced, so damages due to metabolism need not be repaired (no evolutionary gain, maybe even a drawback as it might consume more energy compared to those who don't have it, and as such may be slower to reproduce).

    So I go for the metabolism and sacrifice hypothesis ;-)
  • Nov 22 2011: From what I understand second law of thermodynamics necessitates aging. DNA and the associated organisms are highly ordered and they eventually need to turn to dust (i.e., simple, uniform, unordered molecules). I doubt that evolutionary process can ever overcome this unstoppable equilibriating drive.

    From a purely evolutionary basis, here's another explanation. Let's posit that evolution always tends to produce longer living organisms given the current environment. But by introducing a new product of evolution into the environment, the environment itself changes. The extreme example is that humans whose basic DNA structure has remained unchanged for millions of years today live and breathe a totally different environment than what they were made to live in. In that sense, evolution is always chasing its tail in search of the perfect organism.
    • Nov 22 2011: Nothing's DNA structure remains unchanged for millions of years. Homo sapiens sapiens has probably not existed as a species for millions of years (I noted in another post that the average life of a mammal species is only one million years).. And we were not "made" to live in any specific environment. We arose as a species in the emerging savanahs of Africa, but obviously have experienced great success in colonizing vastly different environments.

      There are no goals for or purpose to evolution so the ideas ot it "chasing its tail" or "searching for the perfect organism" is meaningless. There is no perfection, and no species is static genetically. Even cockroaches or dragonflies, which have persisted as Genera for millions of years have not been spared the slow changes (and the birth and death of whole species) brought about through evolution.
  • Nov 21 2011: You really came up with an interesting question. However, it is my belief that your theory/line of reasoning has a number of important flaws.

    The law of natural selection would suggest that genes for enhanced health and longer reproductive period, which are linked with higher longevity and reproductive success, are likely to be passed on to future generations, which suggest a predisposition of lifecycles to become longer.

    However, longevity cannot become infinitely long at least for 2 reasons: (1) individuals are also part of a population (a group of other organisms of the same species) and a community (a group of other organisms of different species living together and interacting) which may lead to stress, competition for resources, predation, parasitism, etc (2) cumulative death rate - even if you assume that death rate will remain constant through the lifecycle (which it obviously doesn't) less individuals will make it to old age.

    the problems with your hypothesis is that you suggest

    1) "Under the influence of adaptive pressure, it would encourage mutation or variations in order create successful variations and also increase the number of life-cycles and so reducing the lifespan." ...

    there is no such a thing which encourages mutation. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that occur during meiosis or DNA replication.

    2) "Under the influence of competitive stress, the dominance would lead to reproductive success and not the span of mating during ones lifespan."

    Competitive stress is well documented from biological studies to decrease reproductive rates

    3) "In the absence of change in ones environment leading to adaptive pressure, or competitive stresses from rivals to prove dominance. Species would evolve longer lifespans."

    very simplistic & suggests an unrealistic picture that the environment, populations, species and the interactions of all these can remain constant with time
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      Nov 22 2011: If every organism is a product of evolution, then every organism has come long enough and must have developed a genetic predispositions to adapt themselves. This may not happen all the time, but there must be genes which would spring into action in the event of stress or environmental changes to cause changes in the progeny.

      The organism/offspring would definitely benefit from having a variant that may be better adapted to its environment. I only postulate this on the grounds that if natural selection is the most important factor for evolution, then it would have definitely developed tricks to benefit evolution itself, and this is just a prediction.

      I have heard a leading cause of cancer is stress, stress does have a mutative effect.
      • Nov 22 2011: I think that there is some confusion of terms here ...

        every inherited trait is the product of a mutation that, may lead to deleterious effect and hence less likely to be passed to the next generation or, which could enhance the performance of the individual in an environment and hence very likely to be passed to the progeny.

        Mutations are within the genes, or the code made of bases (A,C,G,T) within the DNA, and to be expressed they need to "written" into proteins which have a particular function.

        I would suggest you define stress, but yes stress does have a mutative effect and this has been proved for a number of organisms.

        my take to your question "Why did evolution never solve aging?" is that organisms cannot live forever due (1) increasing entropy (state of disorder in molecules/systems/etc)- the random loss of molecular fidelity, and accumulation to slowly overwhelm maintenance systems (2) genetic factors themselves - ageing has been suggested to be a genetic disease. This may suggest that once past the reproductive stage genes are more likely to persist in the offspring of a particular organism, and (3) the environment - living and non-living which could directly and indirectly cause death. And coupled with ageing due to genetic or entropic causes death rate is more likely to increase in senescent stages
  • Nov 21 2011: Unless an organism produces offspring through its entire life (and specifically unless it produces a greater number of offspring as it ages, which is almost never the case) there is no selection pressure towards longevity. Indeed, the number of surviving offspring this would lead to would very likely be detrimental to the environment and cause negative selection pressure.

    Increasing lifespan decreases the need for replacement of the individual through reproduction, and probably slows the changes in alleles in a population that might confer longevity.

    In humans increases in longevity are the result of better nutrition, standard of living and health care. these things probably prevent selection for the very kinds of changes that would increase longevity in a "wild" population. It seems pretty clear that genes for better eyesight, genes for more efficient immune systems, genes for better problem solving abilities (Jarrod Diamond addresses this) are NOT being selected for, while genes that predispose us to degenerative disease and birth defects are not being selected against. These two things have a definite affect on longevity.
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    Nov 21 2011: 1 - Aging controls population, and eliminates those organisms that are no longer better suited to the environment.
    2 - The illusion that evolution is there to solve problems is just that, an illusion. Evolution is merely the name we have given to the process by which living species adapt to their environments and in general become more complex. In order for evolution to work, honestly, the species needs to keep dying to make room in the environment for the young.
    3 - If you must look at evolution as a process that benefits something, I think Richard Dawkin's has it pretty much wrapped up in the selfish gene. It is not the individual but the genes which are served worse or better by a trait, and aging is extremely beneficial to the adaptation of species, which in turn is beneficial to the survival of the majority of genes in that species. A species that does not age becomes either stuck in an adaptive rut, or consumes all the resources.
    • Nov 22 2011: I agree with adaptation and it being key for a species to survive, however, in order for the change in people to accompany the change in environment, the change has to take place genetically and chronologically. As the environment changes over time so does the change across species. It's important to add the dimension of time into this discussion. As well consider that as complex as we are, our engineers did not design our cells to adapt quickly, perhaps this measure of speed of adaptation is what causes aging.
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        Nov 23 2011: Our engineers? Intelligent design by committee? Surely that just applies to camels?
    • Nov 22 2011: To a certain extent evolution can be seen as an artifact of the existence of genetic material. It mutates, it accidentally doubles itself, it becomes corrupted by bits left behind by virus and bacteria and so on. That is the stuff of evolution. And an unstable environment ,that exerts pressure on organisms that are trying to reproduce and successfully raise (or simply leave behind) their offspring, is the engine that drives it.

      Incidentally, species appear to have discrete lifespans. For a mamalian species the average seems to be one million years, though some may last as long as 5 or 10 million. They either diverge, or the lineage simply stops. At no more than 250,000 years old, we probably have a ways to go yet, but who knows. All too often people indulge the notion that there is some grand purpose for our species, or that we represent the apogee of evolution. This is hubris and nothing more.
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    Nov 21 2011: Hi Anuraag,

    I read your hypothesis and i don't grasp what competitive advantage may derive from living longer. It would require too many simultaneous genetic adaptations to enhance the lifespan of all the different types of cells in the body in such a way that an older individual would be stronger and healthier than a young one. Somehow i doubt that all those could arise at the same time.

    So once reproductive age has been reached, a younger individual would still be at advantage against an older one (better mobility, better chance of healthy offspring) so evolution would tend to reinforce individuals who reproduce right after their bodies reach maturity (post puberty), and who are around the peak of their fitness. Two individuals reproducing from age 15 to 40 would probably have more offspring (and healthier) than a single individual reproducing from 15 to 65

    cheers
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    Nov 18 2011: This is interesting but I honestly do not understand the question?

    Forgive my ignorance but what does aging have to do with evolution in the sense of evolution solving this "problem"?

    I honestly do not see the correlation between the two but I would love to know more about it
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      Nov 19 2011: evolution leads to adaptations within organism to survive in ones environment. A genetic predisposition to age and die doesn't seem to be beneficial or advantageous in anyway, or is it?
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        Nov 19 2011: It is.
        Evolution has little to do with any individual in particular.
        The living cell has to survive.
        Everything that secures the procreation of the initial cell in a better way is favored and becomes dominant.
        If a short life can do this or a long life doesn't matter much to the life force on earth as long as it serves its purpose.
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        Nov 21 2011: Hi Anuraag. I like your questions. I too have pondered the very same thing. Here's my two cents.

        Can you imagine how many billions of people would be on this planet without the benefit of aptosis? We started as a cell. Our cell formed a community of cells. The community of cells formed other communities. Those communities grew more complex. Each community worked to conquer more of the environment to its benefit. Through evolution some communities (organism) developed further (conquered more environment, not just adapt to it) and became fish, birds and even man. Each time the organism left a blue print of what worked best to control more of the environment and imprinted this information into the cells it used to pass on to the next generation.

        In nature, death is a benefit and it is needed. Cancer is a cell that forgot to die which is why it kills the organism in which it lives. If the organism (people) were to start acting like cancer we would destroy the environment much in the same way cancer destroys the environment it lives in--the human body. I'm not a math major, but if someone knew a way to calulate the number of people that would be alive today if we could live for 100, 200, 300 years etc. and only dying of natural causes that number would have to be 70 Billion or so.
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        Nov 21 2011: I must say, I am impressed, I never thought of it in that way.

        I would say it is as long as we can procreate and that is obviously one of the reasons as to why we reproduce.

        Most of the biological complexities on the planet are given a genetic predisposition to live and die.

        What do you think? Do you think living longer would be advantageous?

        For human beings there is really no benefit to live to 100 and this is also the case with other animals.
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          Nov 22 2011: Today if we have to excel at anything we do, we have to spend a majority of our life learning, look at doctors and scientists. There is so much we have discovered already that we have to specialize among specializations to be good at something. There is just not enough time, and as time passes fewer and fewer will achieve their goals.

          We need longer lives, we need to stay mentally young but maybe we should also control birth and manage our resources.
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    Nov 18 2011: I am now 3 minutes older than I was when I started reading this. The only problem I see is that it was 3 minutes wasted
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    Nov 17 2011: What Paul said: "Why did evolution never solve the problem of aging?

    Where's the problem..? Is that not a person centered problem based on fear..?

    ---

    Maybe a more fruitful question is: Why do we see aging (and death) as a problem? [If we do.]
    • Nov 18 2011: I also don't feel death to be so malign. The ideas that new life must take its place are compelling indeed. But what could immortality contain? In us humans, our cognitive functions decline with age. Maybe there is something more substantial than spreading your genes. But wouldn't it be painful, to see your loved ones pass away, constantly experiencing forms of trauma or emotional/psychological pain. I think we must evolve more as a species as far as how we treat each other, how we use our resources.. And on & on. Since the industrial revolution, man sought to gain command over the natural world. Early technologies did not think of adverse effects to climate? If an organism could live forever, how much resources would that require. It would be something with a much lower metabolism, possibly even seasonal hibernation. As a child you dream of endless opportunities. Nature could not sustain the human species, given it's history. We would have to turn back and respect our natural world's health more. I don't believe we could psychologically survive immortality if it were possible until the human psyche evolved proportionately. Some trees live up to 9,550 years but they have a more harmonious relationship to natural world. Why would a form of life so detrimental to it's planet ever discover a solution, we would likely ravage the earth for resources, and destroy it's ability to sustain life before we found a way using science. The entire human relationship with reality, each other, and perceptual reality would have to drastically change before immortality would even be feasible
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    Nov 17 2011: Why did evolution never solve the problem of aging?

    Where's the problem..? Is that not a person centered problem based on fear..?
    It is the ability to swap (genetic) information andcreate new variants that gives the best chance of some of your population surviving uncertain environmental changes.. So if new variations on a theme need to be constantly recreated in a finite system then old ones need to be broken down and reassembled..

    Those that fit best into the current system of resources and limitations will prosper, others will not.
    So the evoultionary process favours the combinations of information which currently work well and is not interested in the individual body that carries them.. If the body is successful enough to reproduce it will likely pass it's propitious combinations on..

    It is only our personal psychological attachments that think that we exist as seperate individuals that can be preserved.. This may well be nothing more than a cultural trend.. Certainly form any wholistic spiritual perspective it is not a thruth.
    The 'self' is illusury. Even if the body did last indefinitely the thing that controls it would continue to change.

    That said and in response to your last point there are many life forms that do, or at least can, live forever..
    Many 'individual' trees, Bristlecone Pines etc don't seem to have aging mechanisms.. Many forest forming trees and grasses, like bamboo, also continue indefinately..

    Also animals do it.. don't know so many examples but remember hearing recently that Lobster cannot be aged and can theoritecally at least continue in cycles of renewal as long as conditions allow.. I would not be surprised at all if it is not infact quite common in many animals..?

    Paul
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    Nov 17 2011: Give it time.....
  • Dec 6 2011: If we're approaching this from a human genetic standpoint then you have to consider that genes won't propagate, quickly, to enact change when there isn't a selective pressure. Almost all human genetic changes are going to be of rates unoticeable to us, barely perceptibly above the norm, because of the cultural influences upon sexual health and family life.

    As for aging you have to ask yourself is there really a significance currently to a longer period of sexual activity to your offspring surviving? How is that limited by things like the menopause and old men losing virilence? And does a longer period of sexual activity actually have any real statistically relavent effect upon the average number of children a person has.

    I very much doubt a longer lifespan actually will contribute to the number of children produced in a western community with good sexual health education. A brief observation is that women are making choices about when to have children increasingly closer to the onset of menopause so they can accomplish a greater number of goals in their youth. If you expand the aging process in a means that produces a greater period of youth I can only conclude that women will continue to choose to have children closer to when the threat of not being able to ever have children compels a desire to do so.
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      Dec 8 2011: This is another socioeconomic selection trend that is well observed, definitely interesting and something new to this conversation.

      There is also a tendency for son's of rich, successful older men having sons who have better chances of mating themselves.

      Both should definitely be leading to longer lives at least among st humans.
  • Dec 6 2011: Being more a philosopher than a scientist, I can best address why aging isn't a "problem". Perhaps you can draw scientific conclusions. 1. Other people are environmental factors, and in today's world, the ideas held by people also become environmental factors which in a real way effect biological evolution. If people were not to age and die, that environment would begin to homogenize (peoples ideas don't change with any predictability or guarantee), and with less environmental variety, there would be less to adapt TO. 2. The gene pool stays the same longer - similar problem: the opportunities for different types of mutations becomes limited.
    Some of your hypotheses seem to favor this kind of homogeneity - a problem is that it is a little self-contradictory to speak of evolution in an environment in which change becomes a non-factor. If such "favorable" conditions did occur, evolution would almost certainly stop too - thus nothing new, including new lifespans. (It is important to consider that while adaptation and mutation certainly will always be the condition of living things, the term "evolution" is almost always used to describe, only with 20/20 hindsight, such a mutation that we qualify as "good". Also, barring such ephemera as "the human ego", where is the evidence that living longer is an improvement? )
    And importantly, if Evolution is your ruler, then measuring by that ruler indicates that the proper lifespan for each living entity = well.... it's current lifespan.)
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    Dec 2 2011: Evolution's aim is not to prolong the lives of the living, but to facilitate reproduction and improve such beings. In order to have a world in which species are constantly progressing and moving toward better versions of themselves, the death/life cycle is a necessity. In fact, the faster we are replaced by newer beings, the faster evolution and adaptation can progress. The very thought of creatures that have yet to be improved upon living long lives goes against evolution. Evolution would only produce immortality/anti-aging if it had created a perfect being that could no longer be improved upon. But, seeing as that will never happen considering the constantly changing universe, immortality never will either.
  • Dec 1 2011: Species are locked into a predator-prey arms race, so the survival strategy would be genetic variation within the species, and strategic alliances with other species. Living for a long time would be like standing still in the middle of a battlefield. In our species we are no longer fully part of this predator-prey arms race, so we see our lifespan increase. Those living to 100+ can be sequenced and their genetic information can be used to increase the lifespan of our species.
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    Nov 27 2011: there are some species of animals that live for hundreds of years. and some scientists even ague that viruses may possibly be the oldest funtional biological structures on the planet, they solved the problem of death by ceasing to live = "nonlife", making them the most deadly and lethal earthly threat to all living organisms, they are like zombie vampires that hijack your cells and multiply within that cell hundreds of millions of times until they explode out of it. they couldnt be much more perfect.

    michael behe after charles darwin's findings came up with the theory of irreducible complexity which theorizes that through selection and temination, structures become ever more efficient and simple. what this means for complex organisms is less friction on moving parts, faster regeneration periods, less genetic flaws, longer life spans etc.

    Death IS an evolutionary advantage becuase of the fact that, becuase of environmental constraints, it makes room for more "experiments" (humans) to be produced. much like in the movie "evolution" the aliens were replicating in a practically exponential rate and rapidly evolving as a result. however thats a convenience of death, not it's purpose! evolution IS moving towards longegity, so long as we can produce the resources needed for our species to thrive. ---Mars here we come
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        Nov 27 2011: HI Tony
        Interesting perspective , enjoyed it.
        Just curious with your SATAN & GOD proposition..... so how you see it I mean the whole kingdom of living being result of GOD's will or evolution ?

        If SATAN can do anything whats so ever is it than again GOD's will ?
        If not SATAN is more powerful to over rule GOD's will......

        Curious to hear your thoughts
      • Nov 29 2011: Tony, I'd like to ask you just one thing. Are you here to preach or to contribute to the conversation here.
        We are talking about scientific facts of evolution and not about theological hocus pocus. Forgive me for being so crude but, I believe its necessary. You have brought up the irrelevant topic of christian mythology, about god and satan here when we are talking about evolution increasing longevity of evolved creatures. I dont think you quite understand the topic here, We are talking about random mutations that occur in living organisms that allow them to survive in their surroundings better. Its not something that the organism chooses to do or makes an effort to do. Evolution is based absolute randomness. When you bring in gods and satan into the picture you're effectively bringing intelligent design into the argument which, is absolute nonsense in itself. If all organisms were designed as version 1.0 and 2.0 we should see less random vestigial organs and vestigial construction in the biological makeup of organisms. For the time being I can give a few examples with regard to us humans, the human eye has its photo-receptors : the cones and rods facing backward with the retinal nerve passing right through it which creates the blind spot. Another being the vestigial organs such as the appendix, coccyx, nipples in males etc.
        Good and evil is a social construct and not something that the natural world exhibits. It might be disheartening but there is no other purpose that anyone is born with in life other than to ensure the species survives. All purpose that we find are what we give ourselves. So I urge you to give yourself purpose rather than to wait for it, and to indulge in a scientific debate when we are discussing science. Its good to believe in things that make you feel good, but one must always know when to draw the line as to the limit that it governs your understanding and way of life. You should govern your beliefs and not let your beliefs govern you. Cheers
        • Dec 3 2011: Stating those words to bring Tony 'into line' must have made YOU feel good. Do you see this self indulgence at Tony's expense as more virtuous or less emotionally driven than his? He seemed to simply refer to our convenient blindness to one side of a polarity that exists in all things. Eg. When we are trying to 'be right' in expressing our viewpoint, we are conveniently unaware we are concurrently aversive to 'being wrong'.

          Sure, in logic and science we draw lines. We 'draw a line' by saying everything must be rational and in accordance with rules or natural laws. But, by 'drawing the line' we create the very problem we wish to resolve. Fundamentally, THERE IS NO LINE. The idea of 'life' being a notable eg.

          THERE IS NO 'LIFE'.
          Some time ago humans 'drew a line' and said; "There is a distinction between the animate and the inanimate." We called things on one side of the divide 'LIFE' and on the other side, 'NOT LIFE'. Then right up to this day,we are trying to find 'the origin of life'. I suggest we don't find 'the origin of life' because we made 'life' up. WE ARE THE ORIGIN. Our logic, made it up! The concept of life only exists inside logic and we generate our logic. So try considering logic as just a self licking ice cream of self generated 'lines'. It cannot ever be the whole truth. A benefit of this idea is: THERE IS NO DEATH.

          So if you want to go down the rationalist's path to pull someone like Tony 'into your line', then be prepared to go all the way with rationalism. You will see that even your logic is funded by 'self drawn lines', or better put, 'irrationality'. I know mine is.

          "There are only two mistakes one can make along the road to truth; not going all the way, and not starting." Buddha.

          So give the religious a break; at least they are couragous enough to accept some irrationality. And as an aside: The accepted scientific wisdom of today is that everything in this universe came from nothing. Now IF THAT is possible, then pray tell, what is not?
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          Dec 4 2011: I would keep myself as far away from this argument as possible but there is one rational man out here that I can entertain. They are all just theories whether religious or scientific, each plausible to a different mind but at least we can look back and say we have found a missing link from the dark ages.
          A lexicon acquired from brushing through a scientific manual doesn't make these people a formidable opposition to science or progressive thinking. So do think twice before you commit to entertaining their arguments.
    • Dec 8 2011: Julius N., good point about the virus. Others took a sidestep to your comment, but let me challenge it directly.

      Virii are living, so they do impact evolutionary aging. I'll explain by first saying: All life requires energy. Energy is the "lifeforce" of evolution and of living systems. Life requires two things: specific matter-structures and specific energy-types.

      Without energy, life ceases. We see this when an animal stops getting energy (eating), it dies (turns to dust, into simpler matter).

      Likewise, when energy is added [to certain configurations of matter], life begins/resumes.

      This is very apparent in a virus, which can be dormant (having insufficient energy to animate/activate), or can be "living" (active) if its environment or a host-cell gives it the right energy. Virii are very unique forms of life, since they can easily move from being "living" to "dead", and back and forth.

      We also see this in more complex life. Some of you might know of Dolly, the first lifeform we cloned (she happened to be a sheep). Well, the hardest part of figuring out how to clone was not the genetics, manipulating cells, or their structures. The most difficult part was how to "breathe life into the clone"... how to jump-start that cloned cell to make it start dividing. It was no simple feat. We know now, all it took was a bit of energy. They "jump-started" the cloned cell with an electrical current. This is another example of energy being added to "a clump of lifeless matter"... to make it living. And this was done to a clump of matter more complex than a virus -- maybe the most complex bit of matter we humans can repeatedly bring to life.

      The ease with which life can be controlled (enlivened or killed) depends on the complexity of the matter composing it. A virus is relatively very simple compared to all life we know, so it can easily be enlivened or killed. For this reason, more complex structures are harder to bring to life.

      Virii =life. Prions =nonlife.
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        Dec 8 2011: it doesnt seem to me that your challenging my comment at all, but rather challenging the idea that viruses ARE living organisms. my previous comment served the purpose of proposing that through evolution viruses have become irreducibly complex, meaning they couldnt be any simpler and carry out the same function. and the same status of optimum efficiency in achieving a objective which allowed bacteria to evolve into viruses is also constantly happening in every complex organism. 30 million years from now our anatomy will be much simpler than it is today, it will be much more efficient. our bodies will repair themselves faster, our organs will optimize their energy use etc.

        but in response to your comment i feel that viruses are neither "enlivened or killed" but rather take on form of active nonlife and non active non life(we do not yet know how to kill a virus). and since viruses are as much living as they are dead, they cannot either be categorized as living or dead. viruses are no longer comprised of systems. they dont have common anatomical charactristics of any living organism on the planet, the function they serve shouldnt be confused with the sturctures that allow that body to perform those functions. its not that im any more right than you are [in a philosophical sense] but our current standards by which we categorize life and non life have NOT been modified to make room for viruses to be categorized as either.
  • Nov 26 2011: Life requires death. Why? from a biological perspective- the purpose of life is to procreate. what is the point of reproduction? genetic recombination. evolution is primarily to become the best version of something(at particular time)- not make that something immortal.
    it is a personal urge to stay alive. moreover death, as many people on this discussion have said,maintains supply and demand ratios.
    this is my take on life- a bunch of chemicals not knowing what they are doing.
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    Nov 25 2011: I like the question. My view is that we forget "the what" that is survivng. It is the gene. The body is like a husk it can be discarded once the genetic material has been supported suuficiently to survive and do it all again. The life span of a gene is unimaginably longer than its incubator. You could easily develop a eugenics program that would result in longer life spans by simply not allowing anyone to bare children until 50 years old and out of the successful offspring lift the barrier once again and then again etc etc. (I use the word eugenics without moral content) If there are any biologists out there who want to prove this in a breeding program on animals I would be delighted to hear the results
  • Nov 24 2011: I'm not an expert,but I feel that the answer to the question of "Why evolution hasnt solved the issue of aging." is a simple one. The answer lies in what exactly evolution is : Evolution is the modification of features in a species over generations, governed by the concept of natural selection and survival of the fittest. When an organism doesnt die, a new generation of the species does not arise, and so evolution cannot occur. Slight mutations in every generation is what leads to evolution.Bye definition the next generation that does survive has to be better equipped to survive than the previous one. The younger organisms of the species have almost no chance of survival without initial support from the mature of the species.That said, I feel that evolution had almost come to a snails pace in comparison to it previous snails pace, which makes it extremely slow in the case of Homo sapiens, thanks to medicine. Its not just the fittest who survive and reproduce but rather almost everyone does, regardless of their strengths or weaknesses. But evolution is still taking place, the rise and fall in the number cancer cases might be an indicator to this. The body is trying to advance in its ability to repair damaged tissue. But the mutations have not reached a stable maturity for the species to move in a particular direction, by having the weaker part of the species overtaken by the stronger. Besides modern medicine would allow us to replicate it in the weaker set of our species too once it stabilizes if we dont artificially find a way to stabilize it first.
  • Nov 23 2011: It strikes me that extended aging is in fact a specific evolutionary DISADVANTAGE.

    On the one hand; It is clear that in animals that care for their young there is a specific advantage to parents surviving until their young are mature, and it there is even an arguement for survival well beyond procreative fecundity (as in humans where females typically survive not only long enough to rear their own young but even to assist in rearing their grandchildren).

    On the other hand; survival of an "unevolved form" of any animal over several reproductive cycles results in the potential for excess competition. While the "survival of the fittest" would favour the more evolved form any capability to learn would provide a potentially outweighting counter advantage to the less capable but "better informed" older generations.

    The consequence of this would be that the species as a whole would fail to evolve and ultimately have insufficient variation within it's population to address "shocks" and thereby be at risk of extermination.

    Following this thinking;
    Animals which don't care for their offspring would have life expectancies ranging from slightly longer than the time required to reproduce (such as the mayfly or the salmon) increasing to address potential risks associated with the development cycle (predictable life-cycle giving a short life while high risk of failure to develop gives longer life requirement)

    Animals which do care for their young would have a life expectancy of betwen say 2 and 4 rearing cycles (2 to allow their offspring to be fully reared up to say 4 to avoid excess competition with their own great grandchildren).

    The other expectation that this thinking would establish is that the more generations a particular animal "cares for" the longer its likely lifespan. (Humans, Elephants etc which care across generations tend to have multi-generational lifespans)
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      Nov 23 2011: I do agree that the affect of age on child-rearing is a significant advantage that proliferated through the population and developed species that adapted such an ability. This is a trait that is advantageous to unique species in unique situations.

      How would you explain the Galapagos turtle? I believe it is one of the longest living vertebrate yet abandons its eggs. It could also be that it is an isolated or rare occurence as well.

      A theory must be simple and able to explain everything but there can be few exceptions which should be explained by other superimposed factors. It must hold true for a majority of populations, measurable by controlling for other traits which affect the same characteristic.

      Is it possible that species started growing older long before they developed the behavior of grand-parenting? Uniquely Humans and Elephants are species which have barely any competition and adapt their environment and so have to face less adaptive pressures.

      Although there are other similarities as well, we have acquired learning so a longer learning period is definitely a benefit. But the greater apes have them too but have little impact on their environment and so have to face adaptive pressures. :)
      • Nov 24 2011: Anuragg, the case of the Galapagos tortoises face an extremely hisk of failure of breeding with young being very heavily predated with only about 1 in 1000 laid eggs survivng to maturity. Given an average clutch size of about ten eggs and four clutches per year it is easy to see how a simple replacement birthrate would require about 50 years of reproductive life so an average age of circa 70-75. The actual wild avaerge age of about 100 would yield an average of three adult offspring per female so provide for a slow population growth while resources permit. In this case the high level of predation requires that parent is extremely long lived.

        It is of course possible that species started to grow older independently of behaviour my point is that being long lived, while an advantage for an individual and potentially an adaptaion to allow for either long periods of dependency as in many "higher mammals" or high levels of predation in the young (sexually immature), once it has achieved that purpose it ceases to provide further evolutionary advantage (capacity for an organism to adapt to its environment such that its genetic inheritance can be preserved) and can indeed, in cases where learning is involved, provide a specific evolutionary disadvantage by alowing the unadapted ancestors generations out compete their potentially more appropriately adapted descendants.

        My expectation is that species which have extended their life-spans beyond the point where it is delivering evolutionary advantage (as opposed to individual advantage) will be more vulnerable to evolutionary shocks (environmental changes/novel predation/novel diseases etc.) and therefore more likely to fail to respond to those shocks.

        In the case of humans the pre-christian era book of psalms estimates the lifespan of the human as three score years and ten (70 years) the latest UN global estimates suggest the current human average life expectancy is 67.2 years (82 in Japan down to 40 in swaziland)
  • Nov 23 2011: Dear Anuraag,
    Thank you for starting this very interesting debate. All the theories offered here are quite fascinating in the way they represent the scope of human thought. But reading them I kept wondering - Why should evolution solve aging? Aging is evloution's most important "cleaning" and "tuning" mechanism. Just like in the forest it created an Eco-system with lots of subsystems that consume its own weak/dead in order to move on. No matter how much (or how little) we understand the mechanism of aging itself, the way I see it, the question you posed is the most ancient one - why should we die at all? Or - why should we become unproductive and unattractive? These are questions of human vanity that evolution seems to be unable to solve :-). it reminded me that in the Old Testament they list names of very early forefathers and count their age in hundreds of years, plus list numerous offsprings these men had way after being 100+ years old. Either Earth was populated by some alien species that left no fossilized footprint, or people couldnt count very efficiently, were impressed with those who succeeded to live longer than average, sanctified old age in their religious rituals, hence gave them more women of child-bearing age.

    I do agree with you regarding the "absence of change in ones environment" leading to longer lifespans - I know of the elderly men in Caucasus mountains who live way past 100, usually in excellent health - and never been anywhere else. They live exactly the same way their ancestors lived for centuries, they are not "trying new foods", and in my eyes represent a perfect balance of systems, the kind of successful evolutionary adaptation you are talking about. But they still look old, their aging process is evident. Too bad so much of human life course involves migration, forced and/or elected, during which the elements, which become stressors, really do a number on our organisms. Anyway, thank you for posting this question!
    • Nov 24 2011: Hello Elina. You make an interesting point. Some individuals are more prone to ageing/death at younger stages which may indicate that some individuals of a given species (say humans for our purpose) have a genetic predisposition for longer life-span.

      The way I take it is that ageing is a natural process occurring within each individual. There are a lot of papers and posts which suggest mechanisms how this occurs (entropy - the state of disorder in molecules, cumulative free radical damage, etc). This process may make the interaction with the environment less efficient for the individual and hence increase likeliness that abundance/absence of several environmental factors (predation, parasitism, diseases, food availability, etc) could become lethal to the organism.

      An evolutionary stable strategy which could have evolved with time could be "you are less likely to live once past reproductive stage given the natural degradation of your building blocks (molecules, organs, etc), so dedicate your time and energy to nurture/rear your young" (which are a 50% copy of your genes if reproduction is sexual")
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      Nov 30 2011: You may find it interesting. Elina, to see in the Old Testament, to which you made reference, that the relatively long life spans of the patriarchs was a reality only up to the great flood of Noah's day. After the flood lifespans were greatly reduced. Hmmm. Perhaps there is a third possible explanation other than alien occupation or poor counting skills. The earth was shielded from the sun by a thick water barrier which fell to earth in the 40-day deluge. After that man was exposed to a whole new formula of solar radiation. Since then the nominal human lifespan has become "Threescore and ten years". Welcome to TED coversations.
      • Dec 3 2011: Thank you for bringing out this point. It has always impressed me that despite not having the water barrier, Abraham lived to the "good old age" of 175 years old. In addition, I have always admired the fact that through the Mosaic law the Israelites were given laws on hygiene, which I'm sure helped them ward off diseases that were probably common in the nations around them. But I have never investigated longevity in ancient Israel as opposed to other early civilizations. Maybe I'll do some digging around. I always enjoy reading your comments Mr. Long!
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          Dec 3 2011: The first 8 patriarchs died at about the age of 900 years, except Enoch who walked with God at the young age of 365. After the flood they began dying at about 400 years of age, then about 200. That is very dramatic, from 900 up to the flood, and 400 immediately after. Abraham, Isaac and Jacob each made it to the mid-to-high 100's. I am no student of secular history, but my impression is that there is no record of lifespans of Gentiles anywhere near as complete as Genesis 5 and 11. That makes your curiosity difficult to satisfy Mary. If you research it I would be interested in your findings.
      • Dec 3 2011: Great! I'll let you know.
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          Dec 5 2011: Yes, Mr. Francis, I found it very interesting to read the biblical explanation for the rainbow as a reminder that the world would never again be destroyed by water. Otherwise it seems likely that man would have lived in fear of rain, rather than seeing it as a blessing. Thank you.
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    Nov 22 2011: In a sense, we live forever.

    Our component parts feed life, most of us pass on our genes, and everything we do affects the world around us.

    Wouldn't evolution, if it selected for longevity/immortality limit the number of organism which are immortal?

    Would the immortals control their own population, ala Highlander?
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    Nov 22 2011: There are many interesting theories on the ageing process. I conducted some research on ageing in the final semester of my Masters which was based upon the Free Radical Theory which Denham Harman formulated in 1956. The basic idea is that, over the course of an existence, a species' genetic material, particularly that which is contained in the species mitonchondria, gets damaged by very reactive oxygen compounds. Usually, the body has self-repair mechanisms to deal with damage, but sometimes the damage is so pronounced that the repair mechanisms are overwhelmed. This damage accumulates and starts having deleterious effects leading to ageing and death in an individual.

    There are quite a few competing theories of ageing. Another I can think of is the Disposable Soma Theory. I have not studied it in depth, but you should find ample information on it online. I think it is similar to your "emerging question", the idea that sexual success is given precedence over the body's survival past its prime. One can easily see how the body, past its reproductive purpose, confers very little advantage to the genes that are trying to propagate themselves.

    I find looking at the whole question from the point of view of genes rather than individuals or species might help (cf. Selfish Gene, 1976). I think your idea (or theory in the colloquial sense) is a good one (a much better one by far than most of the scientific ideas that have been suggested by unlearned individuals here on TED), although I think there are some objections that could be raised here and there. I would agree however that increased lifespan in a constant environment could be a decisive advantage, particularly if reproductive lifespan increases accordingly.

    I'd like to go over this idea again later when I have more time, so I'm leaving this comment here, but I'll be back in a few days to discuss it more deeply. Have you considered studying this matter further?
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      Nov 23 2011: Mitochondria is only passed on from the mother to her offspring right, then a statistical study on whether the longevity of healthy individuals is inheritable from the mother and the correlation to her longevity would be definitive. Considering we control for other factors or statistically eliminate non-mitochondrial reasons for aging.

      Do you know anything about when Mitochondria replicate/replenish themselves? Is it only during cell division? If that is the case then we might also establish a correlation between the longevity of the first-born Vs the second-born. As the second-born might have a shorter natural lifespan as he must have inherited a more aged mitochondria to begin with. Is it possible that the Galapagos Turtle lives upto 200 because of a slower metabolism and less oxidative stress?

      Thank you for the remark. I am just a catalyst, the idea belongs to our collective understanding. :) I am deeply interested in evolutionary psychology not so much of biology but I will pursue study and contribute to science much later in life.
  • Nov 22 2011: Evolution is a process, and a mindless one. Most everything I see, hear, or read about by people seems to fall into the trap of anthropomorphosising it. Evolution doesn't care what happens. It doesn't know it is happening. It doesn't know you won't live forever or care about it. It just is.

    Therefore, evolution doesn't care about "success" or "failure." These are human notions. The process has no skin in the game.

    But, ok. If we must look at what evolution RESULTS IN from our "we're-humans-and-so-need-a-story-line" there's a few things to say about 'successful' organisms. Some have been mentioned here. And so, in so particular order.

    1) 'Survival of the fittest' results in 'winners'. If 'existing' is 'winning, then 'winners' are whatever species happens to be in existence at a given time. Right now humanity is in a tie with horseshoe crabs and dung beetles and every other currently existing form of life.

    2) Evolution in the sense we talk of it is 'concerned with' propagation of species, not organisms. Our human desire might be eternal life but evolution doesn't care about that. The question here is about individual humans wanting reassurance that aging and death might be 'conquered' is irrelevant to this natural process called evolution.

    3) As to living forever, well, forever is a long time. I'm not recommending dying, but it seems to me that whether you live 50 or 100 or a billion years, you die eventually, and then you're equally gone, and there's no 'you' left to know you ever WERE there. The sun will go out, the galaxy collapse or fly apart, and maybe the same with the universe. You won't be there to remember how long you lived.

    Have a nice day.!
  • Nov 22 2011: Interesting to spend so much time pondering evolution and ageing instead of staying in the moment and marveling at the miracle of constant change, action and reaction that has allowed us the NOW.

    Maybe it is the ego's necessity for linear representation of time and the human perspective.

    If 'life' were to be defined simply as 'change' then we could say our mountains and rivers, the universe and even time would fit into this definition and be considered to be 'alive'. If this were so perhaps then evolution would be considered to be more about constant 'change'. This shift would require our acceptance of the universe as being alive and accepting it's age, size and rate of change to define its life as much as we use it to define that of our own.

    Instead of concentrating on our 'personal' life we could look at 'change' to see how we are as a participant in that change - how we interact with our environment in time and space - individually and as a species and vice versa.

    As for the argument of higher or lower in a food chain it is more a function of time in that change cycle as any organism may be the hunter, the hunted and or inanimate depending on its ability to act/react in relation to its environment.

    Survival is, again in my view, human ego trying to rationalize our personal and collective actions to have a sense of control over our destiny. Could it be that constant change is evolution's solution to ageing?

    The problem of evolution resolving ageing is to me more a problem of shifting our personal and community perspective to one that accepts and embraces change in the moment.
  • Nov 21 2011: doesn't everything decay anyway? even if i believed in macroevolution why and how would it solve age? even if we stay young, we age. death is a part of life.
  • Nov 21 2011: If the 'selfish gene' hypothesis is substantially correct, then there may be little to no evolutionary pressure against ageing: as we get older, our continued survival becomes more and more irrelevant to the spread of our genes.

    - The link between survival and the spread of our genes is strongest in early life, as long as we are likely to have yet another child.
    - It is weaker, but not inexistant in middle age, as our survival affects our children's survival and their reproductive success.
    - It is close to zero in old age, as our descendents's fortunes no longer depend on ours.

    Within this framework, if a particular trait is detrimental to an organism, but not to the spread of its genes, then it remains largely unconstrained by evolution. Conversely, a trait that would slow down ageing at the cost of, say, increased energy needs throughout life, might actually be selected against.
  • Nov 21 2011: I think its important to get over the Idea of a bonding species just raising there own young and living longer to produce more. After all look at the advantages of having healthy grand parents living longer to help raise there children's children. I also disagree with the idea "In the absence of change in ones environment, or competitive stresses an organism would eventually adapt itself to survive longer". I believe that evolution can only come from necessity.
  • Nov 21 2011: If I remember correctly, the most recent research points to aging not being a natural, self contained process. That is to say, if a person existed in a vaccum after the age of 24, their body would change very little from then on.

    What I remember was that for evolution, growing old is actually an external pressure, where things like bacteria and UV rays and such cause increasing damage to the bodies of living organisms. This gets confused with the natural growth from child into adult which is encoded into our DNA. So in that sense, evolution can't select out the aging process, the aging process is an external pressure evolution uses to do the selecting.
    • Nov 21 2011: This kind of belies the research showing a connection between teleomeres and physical ageing. Even things like perennial plants which rejuvenate themselves through the production of new vegetative growths each season seem to suffer a loss of vigor over time that not even division can reverse.

      I think that the idea of ageing and death as a "disease" is simply incorrect, it is a part of a healthy ecosystem because it supports the cycling of nutrients and ongoing evolution.
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    • Nov 21 2011: Maybe you are referring to this species:
      http://en.wikipedia.org/wiki/Turritopsis_nutricula
      • Nov 21 2011: This may well have an advantage in a very stable environment like it does with cleistogamous orchids (where all individuals self pollinate, often before the flower even opens) But it leads to an inability to adapt to environmental stresses. Clones may live a long time, but the population will succumb easily in times of stress.
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    Nov 20 2011: Mr Ready, Me thinks you are making a mountain out of a mole hill. There is no problem regarding aging that death can't solve. Life and death is a cycle, not a linear progression once our ego's get out of the way.
  • Nov 20 2011: It [possibly] has! The so called "immortal jellyfish" can revert back to a younger form.

    But I suppose you're wondering why this kind of thing isn't more common... This might explain it:

    Evolution is a process that favours organisms which have the capability to reproduce. For most of the animal world, death from old age is a very uncommon problem. Creating organisms which never ages wouldn't significantly increase that organism's chance of reproducing. It would have died from something else long before it's longevity gave it any sort of advantage. There's not enough reason to select for it.
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      Nov 20 2011: Hey Julien!
      You are absolutely right, since aging in the natural world is rare there is no significant advantage in selecting to repress it unless there are negligible survival stresses in ones environment. Which leads me to my hypothesis.

      "Under the influence of competitive stress, the dominance would lead to reproductive success and not the span of mating during ones lifespan."

      I believe so since through selection when a life form has evolved processes to grow and repair itself, there was never an advantage in ceasing to do so or develop catabolic processes which destroy itself unless they may prove advantageous to prove reproductive dominance.

      I believe so from the premise that testosterone, insulin and stress hormones are essential for the organisms survival but they have negative effects on it's longevity. There are many such processes which are counter productive on the long run.
  • Nov 20 2011: Hi Anuraag,

    I think you have missed an important concept of the evolution process, and that is that it selects for the strength of a species offspring. So, for any species, evolution and its adaptive pressure (in most circumstances) does not select for aging after the reproduction process. In the case of humans, genes that increase someones chances of living to 120 years old, will not be actively selected for, because those genes will not provide any substantial advantage to the offspring that will complete the child-bearing phase of their lives before they are 'old'.

    You wrote earlier that "evolution leads to adaptations within organism to survive in ones environment. A genetic predisposition to age and die doesn't seem to be beneficial or advantageous in anyway". I think you are very nearly right. I would just clarify the first sentence to read "evolution leads to adaptations within organisms to survive in ones environment so that they can reproduce." After this, evolution doesn't actually play much of a role if at all.

    I hope this makes sense!
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      Nov 20 2011: Thank you for the correction, You are absolutely right as it is about reproduction but the question remains the same.

      As far as adaptive features of any organism are concerned, the arsenal for reproduction are by more well evolved and saturated than any other features as it is ultimately the baseline for making copies of oneself. Since that is the case, why not increase the span of mating by living longer given that it has a secure environment free from competition and predation.

      Otherwise, Evolution is most definitely a minimalist I suppose. :)
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    Nov 19 2011: There is in fact a creature that can theoretically live forever.

    http://green.yahoo.com/blog/guest_bloggers/26/the-world-s-only-immortal-animal.html

    This creature has no brain, no organs, and is simply just cells that constantly reproduce and regenerate. There are a few plants and trees that are able to live thousands of years because they grow so slowly. To live forever means that we must be able to reproduce our organs/cells/muscle or that we need to prolong the damage of these organs/tissue until we almost never age or to replace each part of our body that has suffered any damage from age however this means that we would need to replace the brain as it will eventually deteriorate or we could preserve our brain and build an artificial body that can be replaced when it is damaged.

    All of these possible ways to live longer are simply theories that have proved difficult to test and difficult to do. We have not been able to rebuild organs or muscle in our body, we have not figured out how to artificially build organs (at least not all of them) and we have not learned how to preserve our body so as to slow down the aging process.

    Humans are making efforts to prolong the lifespan however the only way to live forever would be to regenerate ourselves. Cancer is cells that are defected. Cells make replications of themselves but occasionally they create a cancerous cell. Each person, on average, will have cancer 7 times in their lifetime. However, when they are older, they are less able to defeat the cancer and thus the cancer spreads. So, if we were able to find a way to regenerate our cells, the chance of getting cancer would increase dramatically. The brain's cells do not regrow. So, unless we can also find a way to regenerate the brain cells, we could not live forever as our brains would eventually die.
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      Nov 20 2011: Interesting correlation to cancer, as it is apt since evolution is also a result of the mutations within one single cell and so is cancer, differentiated only by which stage in life it happens and where.
      • Nov 20 2011: Cancer is a man made disease. ( i will run, duck and hide now!) :)
  • Nov 19 2011: Death came to life with sexuality, billions of years ago.

    If organisms don't die, there would be no advantage of sexuality. Because new combined lifeforms couldn't compete on each other when the old ones still in place occupying ressources.

    New Studies on single-cell-organisms show, that even they seem to prefer one daughter-cell with all defect material and the other with all-good material (inequal distribution).
    The purpose seems clear to me, to eleminate defect material in case of good conditions, and also to have a larger variety in caser of changing conditions. This was thought to be exclusive to sexual reproduction before.

    So death is seemingly of evolutionary importance - even if it is not part of the life-cycle of an organism.

    This means to me that death is bound to evolutionary matters, and therefore not of importance for human evolution anymore (in the western civilisation of abundance). I personally believe that bounderies of lifespan are only defined by evolutionary necessity, and we are in a position to work out how to influence it.

    It gives us the power to decide ourselves, where chance and randomness play the only role in the moment. So I see it as an imperative, or could anyone justify to let random chances decide over life and death of peoples?

    There are also economically reasons to do it, because the civiliosation that has control over aging is expectet to have a higher productivity, and less health problems. I believe, nowadays social conditions form our evolution more than economic aspects. The better you do in society, the better the chances for your offspring are.

    If there is no competion on ressources within our species, death is obsolete.

    Strange to see that there are a lot more children, where economic pressure still controls surviveability. Like in Africa. Western people don't realize how good the conditions for their children really are. They are more concerned with individual matters, like living longer. lol
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      Nov 20 2011: Is it so? Thats a new way to think about it.

      If every organism is a product of evolution then there must of course be underlying mechanisms within to aid such a process. In the event of stress and evolutionary pressure, every organism would seek to pass on variations or by itself induce mutation to seek one which could be better adapted.

      So on the long run, genetic change must be directly proportional to environmental change.

      So may be in the absence of environmental change or stresses there would be less random mutations which I suppose are the cause of aging and could eventually lead to longevity.
      • Nov 20 2011: I don't think cell-damage or mutations are the reason of aging, these are the implementations.
        Death is just an accidently consequence of the nessecity of ressource-distribution throughout different generations.
        The Body decrease repair of cell-damage, and in a careless way this leads to more and more problems until death.
        The Body does that in the first place, because (from an ecolutionary perspective) it makes more sense to distribute ressources to a newer, more modern (and better adapted) organism, than to repair an old lifeform adapted to the past.

        It deals with the problem of living on a planet that is constantly changing and has limited ressources. By stopping the repair-process life secures that ressources become available again, which is crucial for the ongoing development of new lifeforms and their competition of adaptations, that enables nature to stay alive even in ice-ages.

        Nothing on this planet is stable, lifespan must be short, so that adaptations to the allways changing mother earth can be made, and have a chance to succeed. Also the lifespan has to be of an duration that make the world calculatable, otherwise an organism stands no chance against climate.

        I found better words before but after submitting there has been only one sentence -.- so I had to write again ...
  • Nov 19 2011: "but what surprises me is why is there no form of life that can live forever?"

    So.. no deaths, only births. Interesting population scenario.
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      Nov 19 2011: There would still be global warming and mass extinction, but seriously there are enough factors out there like competition, predation, food scarcity, drought etc. In the absence of all such elements why does any organism have to be destined to age and die?
      • Nov 20 2011: Nothing around us is static. Everything is in a constant state of motion, of births, deaths and re-birth, whether it be plants, animals, mountains, oceans, stars and so on. In the case of humans, aging, death and birth is perhaps less about the body and more about rejuvenation of minds, of ideas and the creative process which is necessarily dynamic. It is perhaps about optimizing our understand of us - and we are not there yet.
        Biologically less complex species may find advantage in living forever, but even they must get bored sometime.
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        Nov 21 2011: Anuraag, "...there are enough factors out there like competition, predation, food scarcity, drought etc. In the absence of all such elements why does any organism have to be destined to age and die?" - Maybe it doesn't. The point is you've removed all the elements that are there in the natural world. Those things can't be wished away or removed by technology, unless a species gets to the point where it has complete control over every aspect of its existence.

        One way is we'd have to "simplify" the biosphere, perhaps to humans and wheat, or some small number of food species, and simplify "humans", because "humans" are currently a complex ecosystem in which cells of foreign species outnumber human cells 10:1 http://engineering.curiouscatblog.net/2008/09/28/foreign-cells-outnumber-human-cells-in-our-bodies/ as well as making us and all the GM food avoid natural mutation, and growing food in sterile hydroponic "soil". We'd have to build a shield round the planet that somehow just lets in the useful photons, and no physical matter in case it contains microbes. Once hermetically sealed we can live in splendid isolation. Why? Because everything "would like to" eat us. Life evolves to exploit energy sources like us. A more likely scenario is we seal ourselves individually from the ecosystem outside us. We're on that course, sterilizing our homes.

        Trying to artificially extend individual lifespan is perhaps one of our greatest threats as a species. Imagining us all healthy and old denies the evolutionary ingenuity of the things that are out to eat us, from which we would have to spend more and more energy/money/time defending ourselves. The antibiotic arms race would go further into overdrive. The "immortal" jellyfish is on borrowed time. Something will decimate its numbers eventually.

        Becoming immortal depends on stopping EVERYTHING in the biosphere from evolving, or isolating ourselves from it at the molecular level (stopping viruses getting in to our bubbles).
  • Nov 18 2011: Simple! Evolution depends on the genetic variation and natural selection involved in reproduction. The reproduced have to replace the reproducers, or it wouldn't be "evolution"!
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    Nov 18 2011: Maybe evolution wants to make new chances for new combinations to get up to bat?
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      Nov 19 2011: Simple but makes sense! :)
    • Nov 21 2011: Hi Debra!
      I love base ball! :) ( evolution is a tricky ball game!) Batter Up! :)
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    Nov 18 2011: Sexy old men.
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    Nov 18 2011: Some forms live longer than others, i think a series of trees that is all one life form is said to be thousands of years old... I would actually propose an odd reason for this... Creatures with a brain, have to die... We need fresh debugged hard drives... I think it's kind of evolutionairy, in the sense that if you live for 200 years, you have 180 years of mostly obselete data, that your spreading to your community, like a virus... So we have to, eventually, as conscious beings, let the old die and the young take over. We're not necessarily close to a dangerous threshold yet though, 200 might be pushing it, can you imagine how little of your information would be accurate at 200 years of age, in a fast moving knowledge world like ours?
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    Nov 17 2011: it did, by evolving to human brains that can now come up with ways to reduce or halt aging. faster and more effiecnt than doing it yourself
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    Nov 17 2011: In addition to what Gerald O'Brian has said, you could also consider evolution as a sort of bottom-up process, in which you part with simple cells that have short lifespans before they reproduce and gradually develop better mechanisms that allow that life form to live longer.

    Given that particular path of improvement, it becomes really hard to a species to achieve immortality, because it has to constantly compete and survive in it's surroundings. Only when the need to compete is eliminated from the equation (for example, by not having any more natural predators) and the environment is no longer a threat, natural selection can focus on developing anti-aging mechanisms.

    We humans might be able someday to reach this step, even without intelligent design. As we are closer to detaching ourselves from the direct dependency of nature, becoming a Type I civilization in the Kardashev Scale, and with some cultural changes (specifically, acquiring the habit of having multiple breeding periods during our lives, for example every 20 years), eventually mutations will lead to longer-living individuals.

    However, it is to be noticed that if another group of humans went the opposite way, living short lives and reproducing quickly and having many children, AND the longer-living ones don't have as many children, the first group could outnumber the long-living ones, filling the gene pool with short-life genes. If we assume that both groups of humans can mate with each other, then the final result will tend towards shorter lives.

    So yes, in my opinion, only by intelligent design is it possible to overcome all these issues and create a truly immortal individual.
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      Nov 18 2011: Is it that our metabolic processes are over-compensated for competitive advantages in their sexual prime which prove detrimental for longevity?
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        Nov 19 2011: I think they are, because usually abundant resources in an environment mean a wider variety of species that compete for those resources. In that case, an animal that reproduces and adapts quickly is more suitable for thriving in that environment, because it has a competitive advantage in it's large numbers.

        If we look at the opposite scenario, where the creature has to survive in an environment which has fewer available resources, longer living creatures would have the advantage. As food and water is scarce, it would be highly inefficient to reproduce in large numbers, because most of the descendants would die of malnutrition. Instead, it makes more sense for a creature to live longer and have descendants only when it has found enough localized food to do so. Between those periods, the creature shouldn't age to avoid problems that could prevent it's reproduction.

        The thing is, there are so many factors involved in the survival of a species that limit the possibilities of immortality that it would not make much sense for evolution to develop an animal with those capabilities, because if an immortal animal does appear, we would have to redefine the concept of reproduction, as the traditional one has no sense under this paradigm.

        The fact of having descendants would only be necessary to prevent extinction from unnatural causes (accidents, predators, basically anything except aging).
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    Dec 16 2011: That was quite confusing...not sure how to respond or in which order, so I will just share what I know:

    Bacteria basically life forever, since they only copy themselves. During that process some errors can sneak in which might make them more or less efficient at surviving or have no immediate effect at all. That leads to a slow evolution, which is ok as long as the population is as huge as bacteria populations are. Survival is pretty much luck since these organisms are so simple and therefore vulnerable to environmental conditions. Again their number helps the species to survive.

    Sexual reproduction is another story. The possibility for change in the genome by mixing two of them instead of copying one is much higher, which leads to faster adaption and therefore bigger populations. Also the complexity of the organisms increases drastically. With higher complexity comes higher vulnerability to errors during the cloning process(a glass of water can destroy a computer, but not an abakus to use a simple allegory). these errors accumulate in multicellular organisms until they cease to function, which is called "aging". The errors in the process can happen randomly which is rare or be induced by environmental factors such as chemicals or radiaton.
    In short: We age, because we are too complex to function longer than we do.

    And to adress the longevity:
    Every individual of a species has a lifespan that is high enough to reproduce and in some cases make sure the offspring survive. Anything else would be a waste of resources that would harm the population. This lifespan is determined by the environmental conditions and the sice of the organism. Big organisms that live long evolve in stable environments and have slow reproduction rates. Smaller organisms that live shorter evolve in less stable environments and have to reproduce faster.
    In short: You live as long as you have to, but not longer, because nature can't afford to care about individuals
  • Dec 9 2011: Your hypothesis does not seem to answer your own question. It maybe more appropriate to ask- Why do some species have longer life spans than others? If you are in fact trying to answer this question then I believe you have provided a hypothesis that confuses 2 elementary principles that are essential in understanding and explaining evolution and natural selection ie. Individuals adapt. Populations evolve.
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    Dec 9 2011: Evolution HAS solved aging.

    The modern shark has been around for about 100 million years. If that isn't a long life span, then I don't know what is.

    Evolution doesn't work on an individual scale. It works across entire species, and can solve the aging problem when you look at it from the perspective of a species, and not as an individual. I will die, but my children will live on. Presumably, they will have children, and those children will have children, and my genetics will continue to live on forever.
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    Dec 8 2011: The purpose of evolution is not to prolong life, it is to ensure a specie's ability to procreate. Evolution never solved aging because that isn't evolution's problem to solve.
  • Dec 6 2011: I believe that aging must be the best possible outcome for humans.
    Without aging we'd have a harsh choice to make:
    No new people
    Or mandated 'exit strategy' for current people.
    Either one is unfavorable vs. what we have.
  • Dec 6 2011: Because it didn't need to.
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    Dec 6 2011: I believe Aging is definitely a problem, and with all due respect and humility, I believe it is a design flaw. Evolution has not kept up with Entropy. Humanity now has the chance to manage Aging. I believe that if Humanity got along with itself, we could all live a joyful, loving 500 years or more. The Earth could safely hold 20 billion people, and we could also be living on other planets.
  • Dec 6 2011: Being too improbable to ever occur is a bit of an odd thing to say, when the probability of us being here is almost impossible given another chance to start again. I think maybe "age" or "life cycle" or whatever, is relative to the size and time frame of the entity. Say, the universe is infinitely large, and for all we know, will go on for ever. Galaxies last for hundreds of billions of years (or so we think). Stars for many billions, etc. So maybe, because we move at such a speed in comparison to these larger entities, we live much shorter existences, like dogs or cats compared to us, or a cell.
  • Dec 5 2011: Denomyar01,To be honest, I must say that, Yes it did feel good to bring tony in line. I was simply reminding him of the fact that this is not a theological argument but rather a SCIENTIFIC discussion.

    And about the lines that we draw for the categorization of various things like your example of life, there is a line, just that it isn't a distinct line but a fuzzy line. In the words of Jane Goodall, "it's a very wuzzy line, and its getting wuzzier all the time". Ofcourse she was talking about the divide between humans and the rest of the animal kingdom. Yes classification is difficult and we have things that fall on either side and some that dont find a side to fall on, a typical example being the one stated by Tony in his first post, the Virus, it becomes inanimate when in harsh conditions and animate again when favourable conditions prevail.

    To address the last issue you brought up, The religious being courageous enough...hmm.. hiding from simple facts of life and death and crediting an imaginary being for everything good that happens, then depending on the said being to give you presents if you're good... sounds very courageous indeed. I was religious, untill I started THINKING for MYSELF. never turned back ever since, because I get real answers from science and not answers like "That's just how it is" or "god did it".

    Please look into the actual working of the Big Bang theory and quantum physics before you assert that real SCIENTIFIC theories are just made up by a bunch of people as fictional writing. I would suggest a reading of Hawking's 'A brief history of time'. Brilliantly written for the lay man to understand. You could watch his documentaries too if required (which I honestly feel might be required), and if you're even going to venture say that he's not qualified enough to talk on the topic, Im sorry my friend, I have nothing else to say to you.
    Have a good day.
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    Dec 5 2011: For those curious about increased longevity mutations, google Cynthia Kenyon (a TED speaker) and her daf mutations. (This concerns C. elegans, a tiny roundworm, about which more is known than any other animal... I used to do electron microscopy on these for Bob Horvitz, Nobel Prize laureate from MIT) Normal worms have a number of "housekeeping genes" (antioxidants, DNA repair enzymes, etc.) that are usually turned off. In a mutant where these genes are turned on, the worm lives twice the normal period! A small number of insulin-like signal systems seem to control these pathways, and it was found that sugar shortens the worm's life, but only if they have intact insulin receptors. People like Kenyon will probably discover a drug, that, combined with an optimal diet, will slow the aging process! What works in the worm, thanks to evolution, tends to work in people. I think having a small population of long-lived people, who can "bring history alive", and tell future generations what the world was like when there were coral reefs, etc., would be a good thing.
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    Dec 4 2011: i think the reason evolution never overtook age is because without the position of death and decay our bodies would never evolve. the more a organism decays the more it changes/mutates and potentially "evolves" to survive longer within its environmental stresses. of course this pattern only counts within repetition of conspetion of offspring.
  • Dec 4 2011: Honestly Tony, When I saw you comment in a discussion of such high stature,(I hold TED to be of very high stature). I did not expect you to fall so low to the level of trying character assassination. I honestly thought you would understand that bringing theology into a scientific argument is baseless and irresponsible, and yet even while trying to insult me over here you bring it up over here. Now I truly am ashamed to be a part of a conversation where such and ignorant and childish attitude can be entertained. I'd like to wish you all the best in your endeavors to try and convert people. I dont insult people till I know them, so have a great day. This will be the last time I waste my time on you. Cheers
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    Dec 2 2011: These are some sensible theories widely accepted by the Scientific Community that I stumbled upon while browsing. Although that is what this conversation arrived at independently, thanks to all the incredible contributions. Cheers! :)

    Mutation accumulation theory: From the evolutionary perspective, aging is an inevitable result of the declining force of natural selection with age. For example, a mutant gene that kills young children will be strongly selected against (will not be passed to the next generation) while a lethal mutation with effects confined to people over the age of 80 will experience no selection because people with this mutation will have already passed it to their offspring by that age. Over successive generations, late-acting deleterious mutations will accumulate, leading to an increase in mortality rates late in life.

    Antagonistic pleiotropy theory: Late-acting deleterious genes may even be favored by selection and be actively accumulated in populations if they have any beneficial effects early in life.

    ‎"If you can't explain it simply, you don't understand it well enough." ~ Einstien

    A Good Read:
    http://longevity-science.org/Evolution.htm
  • Dec 2 2011: Hi and how are ya? Evolution is what it is. Humans age. Food chains, are a fact of life. ( crap, another wrinkle) :)
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    Dec 2 2011: Who said that immortality is the purpose of life. That is just something humanity came up with and we have been around for a couple hundred thousand years. Why should the process of evolution have a goal.
  • Dec 2 2011: Well the human species is genetically "programmed" to live to 120 years. But due to the tremendous amount of stress in our world, and due to killing off all the other killer which allowed cancer to flourish, the average life expectancy of men is only 73.7. That's around 58% of what we can live to ideally.
  • Dec 2 2011: I would say that evolution "solves" problems that it has access to. In other words, what would be the selectable environment for longer life? Success in evolution comes from variability and selection. If organisms didn't die, then there would be no evolution at all. Some organisms have success by having very short lifespans, while reproducing "like flies," other organisms are a tad slower at reproducing, but are able to survive longer and gather the strength to help the offspring survive, et cetera, et cetera.

    Evolution is a natural phenomenon, not an intelligent agent.
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    Dec 1 2011: might have something to do with order and disorder, after all we are matter essentially.
  • Nov 30 2011: I do not think it would be in evolution's interest to solve aging. Aging and death are necessary for evolution. If the weak ones do not die, then there is no evolution.There would still be a couple accidental deaths and competition etc. But the number of deaths would be less. This could increase crowding and therefore competition and just balance out the death toll.

    I do agree that we would probably live longer if our environment was unchanging though. We would just evolve to an optimum stage and remain that way. But given that our environment is ever changing and that we are constantly confronted with new viruses, competition etc, it is only natural that there would be some regular 'pruning' going on to keep the amount of genes circulating abundant. If we were all the same, then mass deaths would be even more frequent.

    I do wonder how species that live longer cope though.
  • Nov 30 2011: I am going to say something that. Does not fit at all! But maybe because we should learn to participate our surroundings more, before we get the privelege to stop aging. Understand total bliss, nirvana.
  • Nov 30 2011: Evolution did not solve aging because aging and death are part of the evolutionary process. In order to evolve individuals with traits which are not favorable to their environment will die. The individuals with traits that are favorable to the environment will live and reproduce and a greater percentage of the species will acquire these favorable traits increasing the odds that the species will survive.

    The problem with removing aging from this process is that it would slow evolution down considerably. Death would still occur without aging (individuals of a species could be eaten, drown etc.) But the rate at which evolution would occur in a world without aging would be much slower and thus detrimental to the evolutionary process.
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    Nov 29 2011: I have difficulty with the beginning of the premise of your hypothesis: "In the absence of change in ones environment, or competitive stresses an organism would eventually adapt itself to survive longer."

    Evolution doesn't occur in a vacuum, change is the only constant.
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      Nov 30 2011: evolution doesn't occur in a vacuum, there is change. There are environmental changes and other species evolving around them but lets consider this, there are ecological niches which undergo little change and species which are occupying them.

      Here is some empirical data supporting my hypothesis: cited from Wikipedia
      http://en.wikipedia.org/wiki/Maximum_life_span#In_other_animals

      The differences in life span between species demonstrate the role of genetics in determining maximum life span ("rate of aging"). The records (in years) are these:
      for common house mouse, 4[10]
      for Norway rat 7[citation needed]
      for dogs, 29, in Australia (See List of oldest dogs)[citation needed]
      for cats, 38[citation needed]
      for polar bears, 42[11] (Debby)
      for horses, 62
      for common chimpanzees, 71.4[12]
      for Asian elephants, 86[13]

      The longest-lived vertebrates have been variously described as
      Macaws (A parrot that can live up to 80-100 years in captivity)
      koi (A Japanese species of fish, 200+ years, though generally not exceeding 25) Hanako was reportedly 226 years old upon her death.[14][15]
      Greenland Sharks (A species of shark native to the North Atlantic, believed to be about 200 years)
      tortoises (Galápagos tortoise) (190 years)[16]
      tuataras (a New Zealand reptile species, 100-200+ years[17])
      eels, the so called Brantevik eel (Swedish: Branteviksålen) is thought to have lived in a water well in southern Sweden since 1859, which makes it over 150 years old.[18]
      whales (Bowhead Whale) (Balaena mysticetus about 200 years)

      If you observe closely, it is those species that are living fossils like the Galapagos turtles, tuataras that have the longest lifespans whose ecological niches have changed little over millions of years.

      or

      Even a species influence on an environment both to change and adapt seems to have a significant influence on ones longevity. Both humans and elephants are the longest living mammals.
  • Nov 29 2011: Because evolution was busy resolving so many other issues that we don't have it now.
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    Nov 29 2011: This is an interesting phenomenon because prolonged age of fertility and longer life span might not have been linked. Since fruit flies aren't involved with the rearing of their progeny there would be no advantage in prolonging lifespan. Somehow, this reminds me of the ear size phenomenon. For a long time it was believed that individuals with large ears lived longer. As it turned out ears grow for the length of one's life and those who live to advanced age have large ears. There was a confusion of cause and effect.
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    Nov 28 2011: That is why we are here...to solve it.
    • Nov 28 2011: The question "Why did evolution never solve aging?" is indeed incorrectly formulated, lest it were asked an eternity from now -- currently it should read: "Why did evolution not yet solve aging".

      Assuming that homo sapiens sapiens has opened a game-changing perspective in evolution, it should be noted that humans have already made at least a few attempts to compensate for the frustration of short-termed life, e.g. with mausoleums, inheritage, posthume celebrations, etc.. More recently cloning has nutured wild hopes, and some even believe in cryogenic conservation for later resuscitation, while others try to at least perennize their thougts on the internet... with the next best thing to brain transplantation being currently heart transplantation.

      In the movie "The Fifth Element", death is orchestrated as a highly desirable, thrilling experience -- and similarly there is a more down-to-earth trend with increasing acceptance of self-requested euthanasy.

      In German we say: "Wollen können, was man muss, ist der Weisheit letzter Schluss" (Being able to want the unavoidable to happen is the ultima ratio of wisdom).

      After all, if human life-span were to be massively increased, the frustration of aging would increase correspondingly. Hence, solving this frustration might be the ultimate challenge awaiting humanity...
  • Nov 27 2011: i think the question presupposes that evolution is, and neglects the real likelihood that evolution, as it's being discussed here, may not be. There is a real observable likelihood that within a species there is set an order such that each make according to their own kind and develop, mature, grow, and reproduce; but this is within its own kind.

    On a grander scheme, evolution, although many of its proponents would argue vehemently, does not appear to answer several problems, if any, of great importance. I think aging and death is one of the biggest ones. Isn't it more likely that evolution as an answer just doesn't work, and that there actually might be a better reason for humankind's 1:1 mortality rate.

    You would think that after billions of years—as evolutionists continue to increase these estimations—there might have been a fix to this aging and death problem. And the variability even within the human race would have reached an unbelievable conformity to the most adaptive features. So why is there still so much diversity, variability, and difference?

    I'd also like to pose another question:

    How does evolution, a system built on chance, anonymity, and randomness, ever make come to purpose? It can't, at least, when I think about it, chance and purpose are mutually exclusive and a system can't have both. How is this reconciled in an evolutionary system?
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    Nov 27 2011: I like to think of lifespan as the "refresh rate" on the evolutionary unit. Now that we are evolving to transcend our biological forms (homo evolutis concept), this refresh rate will cease to have the same necessity. For example, through science and technology we are developing ways to physically evolve as individuals. Before our only option was to procreate in order to upgrade the genes we carry.
  • Nov 26 2011: Here's the thing. Genes are passed along only if the animal breeds. The genes that allow an animal to breed are passed on, everything else stays the same generation to generation. The fact that animals die eventually doesn't matter unless dying effects the reproductive abilities of animals.
  • Nov 25 2011: Speaking from a stance of common sense only - I would think that our genes are coded to be adaptive to support the progression of the species, not the individual. That said, it makes sense that an essential part of our physical makeup is some sort of countdown mechanism - for lack of a better and surely more educated in actual scientific methodology, phrase. If individuals were able to prolong their lives or live indefinitely - the planet would soon succumb to the pressures of overpopulation.
    I believe in nature is in fact a predisposition toward balance as well as evolution. When some factor or disaster changes balance, nature reacts. Our efforts towards longevity (often only for a few) via very artificial means seem premature. So many societal issues affect natural longevity - nutrition, disease, poverty. It's true that all life is somehow tied together on this planet by cause and effect, so I wonder if we haven't altered natural processes to the extent that there is nothing left that is "purely natural."

    Great question - and there are surely better minds than mine to answer it! Taking in all the answers and comments is truly fascinating!
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    Nov 25 2011: Perhaps it has, just not on Earth. Perhaps our recent and currently active attempts is just that!
  • Nov 24 2011: This is my opinion only and not something documented, but it may be of some help. Every cell has the possibility to repair itself indefinitely, but as we see they don't. The proof of that is given to us by stem cells, cancerous cells and certain species of jellyfish which are theoretically immortal.

    From what I see the only problem arises from multitasking. A cell cannot focus on repair only. It needs to divide, to obtain food, to perform certain functions for the organism it is part of, etc. Even the so called immortal jellyfish needs to go back to a larvae state (not it's offspring but really itself) and after that return to it's mobile form. But this "pause" to call it so is not advantageous for an animal in a dangerous, resource scarce or competitive environment. So life has immortality at it's fingertips but is too stressed or too busy with other stuff to perform. Our cells are good managers but have the wrong priorities.

    But regeneration phases can be triggered (from what I know) by reduced calorie intake, treatment with certain substances such as resveratrol, and perhaps many others. Of course that these things need to be intensely studied and not taken for granted.

    I ask for corrections because I am not sure of this information and this opinion is mine, not a well researched or studied one.
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    Nov 23 2011: I think it is a low of nature,which can't and mustn't be changed , Many of us would like to live forever young,but then the earth would simplly get off its orbit,it would be too heavy to care so much))
  • Nov 23 2011: It's not necessary! you can say evolution is a very lazy lady, evolution doesn't do perfect it does functional, what is the point in living forever? there are no increase in the gene pool if the contributions to the said pool were always from the same individuals...there would be no evolution if the "old versions" didn't desperate, the new mutations that could potentially lead to divergence of species would be diluted if you crossed "new" with "old" and evolution would take a lot longer, don't you think it took long enough already XD it almost made Darwin nuts!!! =p
  • Nov 23 2011: Could it be that evolution never solved prohibition?
  • Nov 23 2011: The ancient ones in the Bible slowed down aging to the point of living over 900 years old. And some are rumored to still be secretly alive to this day.

    Just what is it that we are prohibited from consuming today that the ancients weren't?
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    Nov 23 2011: Hi Anuraag!

    Sorry to disagree here.
    Evolution only cares about how many descendants you leave (copies of your genes) that are then able to leave more descendants and so on.
    Can longevity be an evolutional advantage in the previously stated terms? May be, there are some organisms that seem to be immortal (in the sense that they don’t grow old).
    But that is clearly not the more frequent evolutionary path.

    Regards!

    JB
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    Nov 23 2011: Our life expectancy in a natural state is 40 yrs old so we are making progress, its those damn free radicals and oxygen we breath thats the real issue.
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    Nov 23 2011: There is not evolutionary advantage to longevity. Traits which lead to procreation are strengthened. If procreation at advanced ages provided a better chance of offspring survival then that would be represented. I believe that there have been studies backing this up with fruit flies by varying the age for procreation. In these cases, delayed procreation increased longevity in offspring over just a few generations.
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      Nov 23 2011: I would like to know more about the fruit fly experiment. Flies must have been selected for those with delayed procreation. By allowing them to mate with each other a line of flies with increased longevity was produced? Delaying the time that flies were allowed to breed would produce longer lived flies in the same way that buying children pants that were too long would produce longer legged offspring. I completely agree with your statements about the lack of value of longevity past child rearing for evolution.
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        Nov 29 2011: The flies were kept from mating until they were beyond normal reproductive age. This meant that only the few that were still fertile at the advanced age passed on their genes. Simple selection principle. Flies that were still fertile at advanced ages turned out to live longer.
    • Nov 30 2011: There are theories of evolutionary advantage for longevity for species to live for at least one generation after procreation. In humans and elephants, for example, it is believed by some that grandparents exist to pass on expertise that they have developed through experience over longer lifespans. This is just one reason for social animals like ourselves to develop longer lifespans through evolutionary processes. There may be others.
  • Nov 23 2011: Why did evolution never solve ageing? Because it doesn't have to; it's not a problem! If a species survives, it is because the species manages to secure two offspring to produce progeny of their own. That's all! If you can do that by the age of forty, why shouldn't you die at forty-one. Evolution doesn't care; as if evolution even cared about the survival of a species; it doesn't. It's just a construct of human minds. Useful at explaining things for us, yes, but a construct nonetheless.

    Your predictions, I think, if you do some research would turn out to be false. Does a coelacanth have a greater mean lifespan that a common carp? Did the moas have a greater mean lifespan than ostriches? Does a lion have a greater mean life span than an antelope? Does a swan have a greater mean lifespan than a goose? I think you will find in all cases the answer is no.
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      Nov 23 2011: Thanks for inadvertently making my case. The Ceolocanth can live up to 80 years while the Common Carp lives up to 50 years. The Ostrich lives upto 40 while the Moa is said to have lived up to 50 years but that is probably just an extrapolation of the Ostriches lifespan to begin with so take any life form on the Galapagos Island for that matter. Lions live upto 30 while Savannah prey upto 25, others such as the Giraffe, Rhinos and Elephants live longer because they don't fall into either category. And Swans do live much longer than Geese
      • Nov 23 2011: I chose my words carefully: "mean lifespan". Human beings CAN live upto c120 years; few do.
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          Nov 23 2011: When talking about evolution and ageing, it is not very useful to talk about "mean lifespan" but "Maximum life span".

          Maximum life span is in contrast with mean life span (average life span or life expectancy). Mean life span varies with susceptibility to disease, accident, suicide and homicide, whereas maximum life span is determined by "rate of aging".

          The differences in life span between species demonstrate the role of genetics in determining maximum life span ("rate of aging").
        • Nov 24 2011: Is it really useful to compare mean/maximum life span of different species and groups? I mean, these have different ways of interacting with their environment (that is their relationship with the physical environment and other living organisms).
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      Nov 23 2011: First, I would disagree that evolution didn't solve "ageing", it solved it very well by allowing it to happened and by determining the right life span for every specie.

      Second, I disagree that after the species manages to secure two offspring to produce progeny of their own they could very well die, in many cases the first generation has to teach the second generation how to raise the third one, to ensure the survival of the species. I would guess this is particularly true in species with few offspring and great child mortality.
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    Arul V

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    Nov 23 2011: Evolution solved ageing but kept secret to maintain the Human ecosystem.
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    Nov 22 2011: One of the most mind wrenching concepts introduced to me was the Selfish Gene concept proposed by Richard Dawkins. Being a mere tool of my genetic material is so demeaning. Assuming that we, as organisms, exist to pass on our genetic material then all aspects of our life and death are calculated by natural selection to optimize that task. It certainly seems to be true looking at such things as the fact that women live, on average, longer than men. The female is more likely to be of help in nurturing a child during times when its mother may be ill, injured, foraging or during other activities that take it away from the child. Once our role of procreation and living long enough to support a child to adulthood we become competition for food and other necessities of survival of our offspring.
    There a re a number of things that indicate that our obsolescence and death is calculated and encouraged. We reach an age when we should have successfully done our duty of reproduction. At that point we cease to become capable of reproducing, and we develop characteristics that indicate that we are no longer "players". How else can you explain such things as the hair thinning on your head while simultaneously growing hair out of our ears and nose and developing eyebrows that look like a briar patch? At the cellular level we have a limited number of mitoses that a cell may undergo before cell death. There is other evidence, I'm sure' that doesn't immediately come to mind.
    So, the problem of longevity is not one of producing it, but discouraging it as far as our genes are concerned.
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    Nov 22 2011: Aging was solved somewhere after Noha built an ark (he was said to be 600 years old). Now a days, aging was solved and people live about 98 years or so, in many cases. Roomer has it that there is an invisible man who lives in the clouds and he has created things like magic talking herbivore snakes and deth-defying people. I guess darwin has pretty much proven all those things have finally been properly dealt with?
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    Nov 22 2011: I gather that evolution has found a nice balance with many animals. I often can observe that an older generation lives long enough to see the success of the next generation raised well enough to be independent and then dies off freeing up resources for the next generation to grow even more and then start producing a third generation. All the time this cycle of having the older generations die off and the newer ones born fairly frequently according to environmental success factors has proven to be successful. Diseases cause by aging then in a way are often beneficial to the species as a whole and future generations as they aid in speeding up the process of evolution. There of course has to be a balance. Diseases that happen to early keep a species from reproducing and ones that happen to late put that species at risk of not adapting quickly enough when compared to other species competing for the same resources which are adapting and evolving faster.

    Buuuut...... does this have to be the case? With genetic decoding and reprogramming people's bodies will not have to grow old. This is of course a goal of many and will probably happen someday if not in the near future then in the not too distant future. At that time problems of over-population will arise (if they aren't already as a result of increased life capabilities in species like humans). Also, other problems can arise too such as if environmental stress factors change, a person who has DNA that is programmed to keep them young and is locked into that program might not be able to adapt well and might not have future generations of random genetic mutations to stumble upon the solution to dealing with new stresses.

    I gather a new kind of evolution is coming, a purposeful one instead of one driven by the randomness in evolutionary mutations. This paradigm will have both its benefits over the old system and its new challenges that must be overcome. It will be interesting to think about!
  • Nov 22 2011: I think Longevity is the coincidental consequence. Organism like human being has no particular reason to live longer than what we are caplable. In a opinion of natural (objectively) entity , human being should be in a cycle of the death.
    On the other hand, we subjectively have a desire to love longer even achieving immortality.(living forever).

    So, my point is that if you would like to have longevity or live longer then you perhaps need a coincidence , not a miracle. You have to collect at least 1000 coincidence in order to make the coincidence into The destiny ; the destiny is the key for your Revolution ,Evolution , Longevity , and even Immortallity.
  • Nov 22 2011: Individual lifespans don't matter. Life expectancy is ostensibly determined by the need for mutational alteration; so the 'longest living', require the least mutational change to cope with their environment. Eg. Bacteria are short lived and mutate regularly to overcome environmental changes such as antibiotics. Giant tortoises and redwoods can cope with their environment without mutational change. Redwoods cope via simplicity and strength, tortoises do so via complexity. Humans can cope by both means, and when they cannot, they engage their complexity (minds) and change the environment.

    So each organism lives for as long as evolution 'let's it dare' before the changing environment selects it to be superseded. This is energetically efficient.

    If the environment ceased changing (if time stopped), things might find a way to live forever.
  • Nov 22 2011: If evolution is seen as a process, then aging is a part of that process! From this perspective, "aging" no more is a problem to be solved. It is merely a part of the whole.
    • Nov 22 2011: evolution is a large fabric like Matrix and an aging is an whole on the fabrix like blackhole in the U.

      So many human being percieve an evolution as a process , but it is actually a cyle. Better put, it is the box that keeps beings securely and safely.

      Aging , so to speak , is hole at the box. Aging is not a problem , it is a path to something outrageously incomprihensible.

      Someday , we wil be able to defeat the path.
  • Nov 22 2011: Evolution has not YET solved aging! I'm hopeful that it will be doing so sooner than later via our technology and medicine. All of our technologies from fire to biomedical research has extended our life spans throughout our entire evolutionary history. Human intelligence, technology, medicine and mastery of the natural world are all parts of our natural evolutionary path. We just haven't evolved the technology yet to solve aging. Getting closer every day though! It will probably be the greatest evolutionary advantage of all time for the species that greatly reduces or solves aging. The skills and knowledge that a person or species could acquire through a greatly extended life span of 200 or more years would be incredibly advantageous. What else could Einstein have done if he had a healthy and productive life span of 200 years? It's coming!
    • Nov 22 2011: We don't "evolve technology". We develop it, and perhaps that technology might get "better" as we (if we) evolve greater intelligence. Evolution ia not a directed process and it has neither goal no rintent, so it is not clear that in our current environment greater intelligence confers reproductive advantage. Such things as resistance to cosmopolitan diseases and shifts in psychology that make us more comfortable in dense crowds would perhps confer greater advantage.

      It is a random process of mutation, and selection through increased reproductive success if the mutated gene confers some sort of advantage. And the selection pressures that work on us are often subtle, and not necessarily descernable. .

      I don't think that in any evolutuionary sense aging is a "problem" that needs to be solved. In fact the older organisms need to die off for any shift in the prevalence of alleles to take place in a population.

      If longevity is increased radically through medicine and technology the ultimate result will probably be to reduce the gene pool, as individuals who can afford the treatments would consume an inordinate share of resources and leave little for others. They would probably stop reproducing themselves as the desrie for self-replacement would be lessened. And those who were relegated to the underclass serving those who had long lives would be selected (by the upper class) for a servile nature and lessened intelligence. A dreary future indeed!
      • Nov 22 2011: I would disagree that our evolution cannot be a self-directed process. Or to think of it another way...evolution becomes less relevant the more we master our natural world. I think there are plenty of examples of us currently self-directing our evolutionary path. We will be able to fully program our genes. There are great strides being made in that field today.

        When, not if, longevity is increased radically through medicine and technology I would agree that there will be a disparity between the have's and have-not's. That however is not our dreary future, it is our dreary present. I'm confident though that we will resolve the economic and social disparity that we suffer from. I'm very excited about the future!
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      Nov 23 2011: Hi Paul, I enjoy reading messages of hope about the future. Sometimes I'm just as hopeful, sometimes very hopeless, based on thoughts like those dennis westler replied with. I'm not as hopeful about solving the economic problem (by which I mean, basically, greed), which I think will be critical in how we deal with all the other threats to humanity's future, from global warming to asteroids to rogue biotech, nanotech and AI, nuclear war, etc., etc. My basic premise is that if we continue to fight over resources, the risk of each of these things wiping us out increases.

      "It will probably be the greatest evolutionary advantage of all time for the species that greatly reduces or solves aging. The skills and knowledge that a person or species could acquire through a greatly extended life span of 200 or more years would be incredibly advantageous." - I see two main problems with this:
      1) Evolutionary advantage is a term that is relative to another population. Maybe you mean simply an advantage over what our species had previously. This, however, is a risky bet, as it's likely to involve a reduction in genetic variation, making us more susceptible to extinction through the above disasters. In that sense, it's an evolutionary disadvantage.
      2) The way computing, psychology, nanotechnology and neurology are advancing, I see vastly increased learning for individuals and humanity through increased speed, bionics and other techniques, which has the advantages over longevity that we don't have to wait another 200 years from inception to attain it. The same advantage could be got by founding an institution in which bright students are funded to learn all day every day instead of turning up to 3 lectures a term. ;)

      But some of my darkest visions involve us knowing an awful lot. Knowing and doing aren't the same thing. We pretty much know what we need to know now. We just don't do what we should, because of our deeply (genetic) competitive nature.
      • Nov 23 2011: Correct, by evol advantage I mean our continued existence. We already beat out our competitors thousands to millions of years ago. We win!

        I'm definitely on board with you about a great uptick in human intelligence and capacity through supplementing our brains and bodies. This too has me greatly excited about the future. I think we will know one day exactly how our bodies and brains exist. knowI fully intend to supplement my body and brain with technology and biotechnology if available in my life time.

        I don't think we can ever know too much. There really isn't anything that says we can't fully know and master our natural world or the entire Universe some day. There is no bad or wrong knowledge. Let's learn it all!

        I too struggle with the issue of genetic variation. I haven't been able to think my way around that problem. A friend once suggested that tightly controlled borders and immigration policy throughout all nations would be one way to ensure genetic divers. Instead of the move to make our entire world one big melting pot it would be best to encourage and celebrate diversity. Even when we can fully program our genetic makeup each unique society and cultures would choose the genetic profile that best matches their own values.

        It bugs me to no end when I hear people say "we are all one" or "we are all one world". We are not "all one" nor do we want to be "all one". Far better if we all maintain our uniqueness and learn to get along despite our differences.
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        Nov 23 2011: There is an economic advantage within our species to live longer. If my parents live longer, stay mentally young to educate themselves and acquire more money, I am more likely to find better suitors and mate more often. But this may apply only to humans and may already be a socio-economic trend.

        But such a trend would continue as I may have a genetic disposition to do so!
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          Nov 23 2011: Good point. Evolutionary advantage was conveyed when humans developed language and culture, and now our reproductive potential is most obviously measurable in dollars - at least that is a persuasive idea. More money means better health care, greater survival rates of children, who are better educated, earn more money, and so on. However, evolution is a compex issue. What seems advantageous within one particular time scale may not be over another, and evolutionary time scales can be very long indeed. So in saying "that trend would continue", one should always recognise that it's temporary.

          Here's a scenario to help understand it: in future almost all the rich people have sanitized their homes and work places (which are just their homes - they don't need to go out much), and have taken advantage of gene therapy over a few generations, so they almost all conform to a cultural ideal of perfect beauty and intelligence. They rely even more on advanced drugs, especially antibiotics, antivirals, antifungals and so on. They grow a limited range of super-foods under relatively sterile conditions. Then some virus mutates such that it targets this genotype, or its food source. The epidemic could wipe virtually all of these "advanced humans" off the planet. Meanwhile, the poor, scraping a subsistence living out of the filth as usual, have the bio-diversity to survive in large numbers.

          Of course, it might not go that way - the rich might have the resources to fight the infection, but it's only kicking the can down the road until next time, IMHO. There is a rational argument that what would be best for humanity is to stop "advancing", but we can't do that, apparently.

          This is also why it's wrong to consider humans as the best organism. Those who appear ahead in the race would seem to be more vulnerable to being destroyed. There are many possible global disasters that could wipe us out, or all mammals, or much more. Bacteria survive almost anything.
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    Nov 22 2011: Evolution itself creat aging process in order to balance the ecosystem.
  • Nov 22 2011: Evolution is a process, and a mindless one. Most everything I see, hear, or read about by people seems to fall into the trap of anthropomorphosising it. Evolution doesn't care what happens. It doesn't know it is happening. It doesn't know you won't live forever or care about it. It just is.

    Therefore, evolution doesn't care about "success" or "failure." These are human notions. The process has no skin in the game.

    But, ok. If we must look at what evolution RESULTS IN from our "we're-humans-and-so-need-a-story-line" there's a few things to say about 'successful' organisms. Some have been mentioned here. And so, in so particular order.

    1) 'Survival of the fittest' results in 'winners'. If 'existing' is 'winning, then 'winners' are whatever species happens to be in existence at a given time. Right now humanity is in a tie with horseshoe crabs and dung beetles and every other currently existing form of life.

    2) Evolution in the sense we talk of it is 'concerned with' propagation of species, not organisms. Our human desire might be eternal life but evolution doesn't care about that. The question here is about individual humans wanting reassurance that aging and death might be 'conquered' is irrelevant to this natural process called evolution.

    3) As to living forever, well, forever is a long time. I'm not recommending dying, but it seems to me that whether you live 50 or 100 or a billion years, you die eventually, and then you're equally gone, and there's no 'you' left to know you ever WERE there. The sun will go out, the galaxy collapse or fly apart, and maybe the same with the universe. You won't be there to remember how long you lived.

    Have a nice day.!
  • Nov 22 2011: From what I've read about genetics and evolution, aging is necessary. We age to reach reproductive age, but the aging continues from there. The basic nature of DNA replication even gives light to this. The telomeres of chromosomes (considered to have some effect on age) shorten with every mitotic division of somatic cells, giving rise to various ills. This is probably the negative that comes with the beauty of eukaryotic evolution and genetics.
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    Nov 22 2011: Hi Anuraag. Good question.

    Evolution doesn't have a "to do list", per se. Evolution is a 'process' not an 'entity', so when you ask why it did not solve this problem of aging, that question cannot really be answered because you are not quite seeing evolution in the right light. I hope that what I say helps, if it doesn't I apologize. :-)

    2 things about evolution:

    1. It essentially means change of an organism over time, and that change can happen in a variety of ways and mechanisms (for example "Natural Selection" is one mechanism of Evolution).

    2. In what we have observed about evolution, based on fossils and current evolution in microbiology contexts, we notice that many organisms reproduce in an effort to pass on their genes to their offspring. So, one can conclude, based on these observations, that an organism need only live just past puberty in order to pass on these genes of theirs, right?

    In other words, based on the above information, this evolutionary process entails an organism living long enough so they can pass on genes (if possible), and not how long an organism lives past this event.

    I do wish that in human evolution aging was a stronger factor though. Why? Humans grow up slowly, both in the womb and out, so it would be nice if there was some evolutionary pressure to live longer because, in the end, it might help our progeny's survival, which seems to be the point anyway. It would certainly be nice for our parents, and even our grandparents to be around longer to guide us through this crazy life, yeah?

    Now having said that, some would say that Natural Selection, a mechanism of Evolution, has made it possible for us to live longer than we have in the past. We live on average 40 more years more than our ancestors used to largely due to technological advances and advanced medicines. But keep in mind that this is a mechanism-and not evolution itself, just one of the ways that evolution is expressed, for lack of better words.
  • Nov 22 2011: Well I don't think there are any tricks to evolution. You either believe that God created things for a purpose without the use of evolution. Or you believe that God created all things with the use evolution for all or part of things. For both of those things the intelligence comes from God. Or you believe that evolution alone is cause of all development then you must believe that there is no intelligence in that development and then there are no tricks to evolution. Evolution unlike what people think is totally random but follows the rule of survival of the fittest. Those things that evolve in a direction that makes them fitter allows them to survive while those things that evolve to make them less fit or not as fit as others will die with their inadequate genes. It is a mistake though to assume that all mutations are improvements. I think also without an overseer of evolution there is no organization or intelligence to it besides the organization of chaos.
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    Nov 21 2011: I believe you should think of aging and death as a mechanism of evolution, not as a weakness or malady to be solved. Our limited life spans encourage us to procreate so that our species may live on, thus creating genetic diversity and allowing our species to continue to adapt to our environment.
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    Nov 21 2011: Interesting question. Didn't evolution solve this "problem" already? I remember seeing a TED talk about a type of jellyfish that is essentially immortal. It grows to adult and then reverts back to an embryonic stage -- again and again.

    As for mammals, it would seem that there just hasn't been the proper mutation. I definitely see extended life times -- if not indefinite -- if we, as humans, can massage our genes into allowing us to live forever.
  • Nov 21 2011: Universe is aging as well.? It's a fairytale that says the spirit of enlightened people as infinite small "matter" floating in all kinds of universe "human" can/cannot imagine. They can be anything they want to be by following the rules the anything requires. :) That's why they say you can see God in anything or everything?
  • Nov 21 2011: Everybody seems to think evolution always goes in the good direction. Evolution is random. Second point is that evolution happens over millions of years. To evolve without technology to the point of being ageless would take millions of years.

    It is more like that we as humans will achieve immortality through technology either by manipulating our genes or by transferring our consciousness into a computer or by some other means. In some since of the word we are evolving faster through technology. Maybe even one day we will become multidimensional beings in addition to gaining immortality.
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      Nov 22 2011: In the future evolution may have little to do with our development, I was seeking to understand/uncover the tricks of evolution and not solving aging itself. :)
  • Nov 21 2011: I believe a computer analogy could answer the question.

    Say that is an ordinary computer. After days of use its system information will eventually get messy. You could do some measures to reverse the process,such as cleaning the desktop and doing a defragmentation. Yet eventually the computer will ask you reboot the computer in order to do some fixes which could only be performed when the system is not being utilized, or the system will crash. It's okay for a computer to be shut down for a while because its information could not be gone even if there is no power supply.
    After some years some components are burnt. You could replace it with a new one and dump the old one.

    While for living thins, a temporary shut down is biologically impossible because, unlike computers, cells need constant power supply to keep its genetic information intact. So living things are unable to do major repairs and impairs are then destined to accumulate inside body until a system crash occurs. Also, living things could not dump out broken vital components and grow a new one, because that requires a temporary shut down of the body, which is beyond the capability of an organic body. Although living things have certain self repairing capabilities, DNA does not provide sufficient coding for handling so many kinds of damage and impair in various situations. For humans, our cells are mostly differentiated, meaning that they could only do what they keep on doing, unable to work out a repair solution should the situation be beyond their functionality. Performing a such a specific repair requires a central command system that could react differently in different and changing situations, like our brain does. But human brains are still too young to consciously manipulate the body in cellular level.

    The key to immortal is to replace broken parts with new parts. Due to limitations of organic body, repair could only occur on a small scale and is slower than getting broken, so natural organics die.
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      Nov 22 2011: there is a difference though, the DNA in most cells contains all the information required to grow any cell in the body of that organism.
  • Nov 21 2011: Would aging not be an advantage of evolution?
    The longer reproductive cycle would mean that there's less iterations for a specific time period meaning slower evolution.
    I thought that's scientists use some type of worm to test DNA mutation experiments.
    Also it's noted that the longer life span of the human species in the last few centuries are mainly the result of the better sanitary conditions, such as clean water, waste management and so on...
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      Nov 22 2011: That is true, our lifespans have increased mostly because of how we have changed our lifestyle and nothing special that we have evolved.
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      Nov 22 2011: I would argue that the life span of the human species hasn't been make longer, only the number of years that any person is expected to live on average. It means that a 1000 years ago there were people that could live a 100 years or more but on average the life expectancy was much lower because a lot of people died as a child. Nowadays thought better sanitary conditions and medicine less people die at a young age so the life expectancy increases, but it has nothing to do with the life span of the human species as a whole (life span is an evolutionary phenomenon, how many years you actually live is a matter of environment and behavior). I would guess that people that survive their childhood a 1000 years ago had better genes that make them lived longer; because today we have many ways to save children that couldn't be saved before we are preserving arguably weaker genes that eventually could diminish the human lifespan. (PD.sorry if any gramatical mistakes, english is my second language)
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    Nov 21 2011: In regards to evolution solving the ageing problem my opinion is the following:

    A. Evolution is a mechanism that allows an organism to survive and it is based on a dynamic equilibrium between stresses and opportunities for the organism within its environment.

    B. Survival does not necessarily have to do with life span. Living longer or living forever does not ensure survival. It is acknowledged however that a longer life span might be beneficial under certain circumstances (relative isolation, absence of pressures) and for specific reasons (reproductive success), which often are related to the emergence of other issues (especially scarcity of food supplies and power struggle over habitat areas).

    C. If for survival to be achieved, an organisms needs to live less, then evolution has already solved ageing by allowing its existence.

    Maybe the issue here lies within the question, as it regards biological immortality as a desirable or maybe the ultimate goal for organisms. Maybe senescence IS the answer to sustaining life.

    PS: Note that this is a simplification of arguments. There is a much longer debate regarding the issue of overpopulation, while the finite nature of our planet's natural resources needs also to be taken into consideration in one such dialogue.

    PS 2: Some organisms have indeed achieved immortality (see the jellyfish Turritopsis nutricula and Hydras), but that only means it is for those species a successful evolutionary trait. If for another species one such mutation or adaptation proves useless or does not promote life sustenance, it would probably devolve, evolve by rejecting the unsuccessful trait or become extinct.
  • Nov 21 2011: I feel like there was no need to "solve" aging before. Old age is actually quite a recent concept, in which previously an organism might be eaten or killed by external factors before they even got to the point of old age. Therefore, there was an evolutionary pressure to avoid being eaten or killed, and nature has done wonderfully in so many ways [intelligence, size, claws, intimidation, chemical repellants, etc]. Old age on the other hand, something completely new, recent, and really only applies to humans [and maybe a few other organisms]. There is really has been no evolutionary pressure to work towards "solving" this, and so nature hasn't "come up" with any answer to it—because there is no need, and that's not how evolution works.
  • Nov 21 2011: I found that 6 days ago:

    Medical researchers decoding the aging process
    By Jean-Louis Santini (AFP) – 6 days ago
    WASHINGTON — Scientists are beginning to decode the complex biology of aging and are optimistic that recent advances in research may lead to treatments that can slow or even reverse degeneration and disease...

    http://www.google.com/hostednews/afp/article/ALeqM5h5YClbs-xaFuWbckcuiuNfIK3UHw?docId=CNG.5068009c85774a90d8eb88798c03ae78.421
    • Nov 21 2011: "Treatments" against aging are likely to remove what little selection pressure there is FOR increased longevity.
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    Nov 21 2011: Suspects that, much like holding evolution hostage for not explaining abiogenesis (life from lifelessness) was projecting too much upon that theory's purpose and scope, the question of aging ought not be put onto evolution.

    In the context of evolutionary theory, be you a Darwinist or neo-Darwinist or Gouldian-Darwinist with its "newish" view of "punctuated gradualism" over "slow but steady" evolutionary change, aging can be seen as discrete and not continuous.

    At what point is the organism complete enough to be able to pass on its genetic legacy effectively?

    There is no doubt that human infants have the requisite genetic material capable of producing new life human forms via "cloning" or "budding". But "effectively" is the key here.

    Would the survivability of such life-forms have the "evolutionary" wherewithal to be able to breach the thresholds between lifestyles shaped by constant reproduction like the "shadfly" and life lived in stages that frees the organism from constant reproduction in what can be thought of as stages that ensure its long-term reproductive potential.

    Perhaps aging ought to be investigated as a chemical problem, the stability of molecules and their chemical bonds as mitigators to their instability relative to the stability of the elements comprising those molecular forms. Even different forms of elements, their atomic structures, are pone to decay as the particles that comprise even Hydrogen come in several isotopic forms each with their own particular decay rates as a function fo their atomic structure!

    Evolution is a core reality in explaining the many different forms of life we se eon earth, and seek to find in the rest of our inter-stellar universe. But laying the explanation fo aging on evolution's doorstep seems a bit of a stretch.

    Until we understand "all" the bases of stability at the particle level, the manner in which lifeforms are subject to those same physical laws regarding organismal stability will be total guesswork.
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      Nov 22 2011: Hey Timothy!
      That is a possibility too, as all molecules do have half-lifes even those which seem like stable, large organic molecules. There can never be enough genetic coding to notice and replenish every molecule that may go wrong. In that case it could be limiting the lifespan of living things too and aging may be in the nature of our metabolism.
      But as it can be observed, catabolism is being altered using mechanisms so readily available to to alter through genes which vary insulin levels, no of receptors on cells etc. So if it is in nature to select for it, It would have.
      Although metabolic aging should be a fact as well, only it must be much slower than what we are observing, maybe in the order of 100's of years.
  • Nov 21 2011: Much like the notions of "critical mass" for any organism, there is a "critical age" for organisms, too. That's why we don't see 20 M large spiders or houseflies that live for 3 years -- the body of a particular organism only 'takes' so much ... also the ability for organisms to adapt to 'negative' or 'positive' change is another element of the process as well. It would be interesting to see 1000 years from now how humans have adapted to diets that include preservatives and artificial ingredients and the impact on the internal organs. E.g. -- the evolution of the appendix in the human body has shrunk remarkably over thousands of years to the nickle size it is today.... interesting idea though, Anuraag.
  • Nov 21 2011: That's the beauty of evolution. Aging-die is required to maintain the current ecosystem. Aging is also a mechanism to choose the ones which could adapt to changed environment.
  • Nov 21 2011: because our sorroundings are constatly changing humans need to adapt, and the only way they can do that is by selecting the specimens that are better adepted, and also disposing of the specimens that are no longer useful for the species.
  • Nov 20 2011: If ageing were stopped, the organisms would stagnate. The whole point is to make something better, not keep old stuff.
  • Nov 20 2011: It has to some extent.
    For most of evolution the cycle of generations was the only way for a species to adapt, aging and death removes useless competition allowing the genetic dice to be thrown more often. In species with a high investment in the young where "culture" transmits behavoural innovation, parents are more useful to the species. In some, such as ourselves and killer whales, grannies are so important we have evolved a menopause which shortens the reproductive life to preserve the skills, knowledge and social support given by the old. Unfortunately since the evolution of sex death was a key part of the strategy. Iit's built into the structure of our cells. So if we want indefibitely long lives(and I do)we need to work on the mechanisms at that level, while avoiding cancer. Not simple, but conceivable. Since we can change and innovate exchanging memes rather than genes, we no longer have to evolve in the tradiotional way. We are now evolving very quickly indeed and the advantages for the species could be enormous if individuals could evolve and contribute for centuries rather than declining for their las 7 to 9t decades. Given our evolution and current situation I see this as the next natural development.
  • Nov 20 2011: Question is moot. Under natural law, natural selection and evolution arise and optimize each species. Why discuss situations that could and should never exist?
  • Nov 20 2011: It didn't need to. We were killing each other far faster than we were out-living each other. And we were obsessed with reaching puberty the quickest to have the most progeny as a form of competition, so quick aging was favorable.
  • Nov 20 2011: Aging is not a problem. It's a necessity for life to evolve. If humans lived forever, there wouldn't be any room for new people, including you and me. Growing old and dying is just a necessary evil (in our view), so that our species (and all others) can survive.
  • Nov 20 2011: Hi Reddy! ( Umm with the utmost respect to your opinion. ) What? What are tournament species?
    Every living thing, has a life span. Yes, evolution is a fact! With respect!! :)
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      Nov 20 2011: Tournament species are those where the male competes for sexual dominance to mate with many females. i.e lions, deer, walrus, baboons etc and pair-bonding species are where the sexes pair up for extended periods to mate and parent. i.e swans, jackals.

      The two are not mutually exclusive and there are species to have characteristics of both. Although in the context above it is a factor of how much does one expend one's resources into competing with rivalry or into courtship and parenting.
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    Nov 20 2011: My hypothesis for Aging:
    In the absence of change in ones environment, or competitive stresses an organism would eventually adapt itself to survive longer.

    A Deduction:
    If every organism is a product of evolution then there must of course be underlying mechanisms within itself to aid such an adaptive process.

    Under the influence of adaptive pressure, it would encourage mutation or variation in order create a successful variation.

    Under the influence of competitive stress, the dominance would lead to reproductive success and not the span of mating during ones lifespan.

    In the absence of change in ones environment leading to adaptive pressure, or competitive stresses from rivals to prove dominance. Species would evolve longer lifespans.

    Just a Theory though! But it would predict that

    Lifespans in living fossils unchanged by time should be greater than their recently evolved relatives.

    Life evolving on isolated landmasses far from competitive pressures should have greater lifespans.

    Living things higher up in the food-chain or with few natural enemies should evolve greater lifespans.
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      Nov 21 2011: Hi Anuraag, interesting questions. Pardon me if I haven't quite understood some of your points, but I'll try to give some answers to why life span doesn't increase as your hypothesis predicts. Imagine two identical species form from one. To help analyse the issue, I'll make some grand simplifications. Let's say these two species migrate (so that their actions in their environment can be separate). The first we'll consider unchanged. The second has mutated to increase its reproductive life (you already acknowledge that post-reproductive life is not directly relevant). So we have the original and a new species. We can expect that the new species will have more offspring. That, I think, you consider a benefit, and thus argue that it should always tend to increase lifespan. But the increased population puts greater pressure on the environment. If these were predators, the prey might be over-predated, leading to a collapse of that prey species and increased incidences of starvation, weakness and disease. Most populations are in sensitive dynamic equilibrium within their environment, and overpopulation is a great threat. If the environment can sustain higher numbers, the mutation may be beneficial, but at some point it will be a hindrance.

      Your last statement about organisms with few natural enemies, and your general argument about stable environments may indicate a misunderstanding. What life does basically is it consumes its environment. Increasing lifespan and slowing reproduction (to avoid depleting the food source) also tends to be a disadvantage because other organisms can take advantage of the slower evolution. The faster one mutates, the less likely a disease can take hold, or a prey can out-evolve you, or a predator...but each individual has to die sooner to avoid population collapse.

      We forget that "environment" is mostly made up of other evolving species. It's an arms race. Not updating is suicide. That's why the sitting duck went extinct. ;)
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        Nov 21 2011: Hey John,
        An example of your stated phenomenon, I have heard Bobcats and hare populations grow and fall like a sine-wave, and if given enough time to saturate even they could eventually develop a mutually beneficial equilibrium to maintain constant populations.

        In the natural world it is an arms race between generations, predator vs prey, their immunity vs germs and they are most likely to become obsolete and die from external factors long before aging sets in. I have come to understand now that overpopulation is the major threat.

        Then maybe aging was one of the most basic evolutionary adaptations of all life, when life started to saturate most of our planet, when it wasn't just individuals but it was required for every one in that species to have a gene which causes natural death that would make it essential for all to clear up the ecological niche of that species to avoid a population collapse. This makes so much sense, and also explains why it could be so universal.
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          Nov 21 2011: Hey Anuraag, thanks for your reply. Yes I think that's right. I'm not an expert, and don't know much about the details.

          "Then maybe aging was one of the most basic evolutionary adaptations of all life" - yes indeed, or perhaps aging and death are essential principles of life. David Christian describes the whole evolution of the universe, and has interesting things to say about life in terms of its complexity and fragility. http://www.ted.com/talks/lang/en/david_christian_big_history.html

          "..at each threshold, the going gets tougher. The complex things get more fragile, more vulnerable, the Goldilocks conditions get more stringent, and it's more difficult to create complexity. ... How do you stabilize those huge molecules that seem to be viable? Well it's here that life introduces an entirely new trick. You don't stabilize the individual; you stabilize the template, the thing that carries information, and you allow the template to copy itself."

          It's theoretically possible that the whole of the oceans might have filled up with copies of some replicating molecule before life got going, either with or without mutations, but that's a dead end. It would simply be mush for another molecule to use as food. Permanent copies are like parts of a crystal. They stop the flow of energy, and get in the way. The "trick" allows raw material to be constantly rearranged by the DNA, which only works if it is released through decomposition. Nothing is trying to do anything - things just stick around by sticking around.

          However, that talk also suggests another important possible answer to your question: the second law of thermodynamics. What this means is that decay is actually the most natural condition - it is what things do in the absence of some organising principle, and what scientists expect the whole universe does eventually. How things can get complex at all (without some guiding force!) is the mind-bender of all mind-benders, but is, I think, the scientific consensus.
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        Nov 22 2011: The Dodo's evolution should be mentioned as well. It's generally excepted that they have not evolved much in the last couple of millennia as there were no natural predators. This is obviously not good for a species survival as they are now all extinct.

        @Anuraag I really like your theory. Funny enough I was having the exact same conversation on another topic a few weeks ago. In a hypothetical, would a specie that is devoid of an challenge and an endless supply of food cease to evolve? Good question.

        As for life expectancy. Since there would be no push to evolve I believe the life span would stop evolving too. There no need for more life time or less. According to nature a perfect balance has been found and no more change is needed.

        Maybe the life span has to do the the complexities of raising offspring. Animals higher in the food chain would produce less offspring due to the amount of resources needed to get an child into adulthood. This means they also need to life longer to make sure that they can have at least a few offspring in their life time.

        But this is just one case and there are others that don't adhere to this tread. It does not explain animals like the African spurred tortoise that can life up to 50 years. They still lay eggs and don't look after their young. Another example some parrots can life up to 80 years and yet their offspring leave the nest just under a month. Plus they do have natural enemies. You theory needs to address cases like this.
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          Nov 22 2011: Hi James. "The Dodo's evolution should be mentioned as well. It's generally excepted that they have not evolved much in the last couple of millennia as there were no natural predators. This is obviously not good for a species survival as they are now all extinct." - It may be a little more complicated than that, or a little simpler, depending on how you look at it. I don't know if it's generally accepted that they didn't evolve much in the last couple of millennia or not, but millennia are pretty short by evolutionary measures (maybe you meant millions of years; millennia are thousands). I'm not sure of the details, but my guess is that their ancestors flew to Mauritius, which is where they lived, and due to the lack of predators they *evolved* to lose their wings. This is an important reminder to people who think evolution adds useful features like wings to "improve" species. Here, the improvement was to remove wings: presumably wings are a liability if they don't provide an advantage - they're a site of unnecessary injury leading to death, for instance. Hence smaller wings were selected for until they became flightless. Then a new predator moved into the environment, humans, and ate them all, although having wings is no guarantee of survival once humans decide to eat you.

          There are things which haven't evolved much, like crocodiles, that haven't gone extinct, so it's not correct to devise simple rules about rates of evolutionary change and viability. Probably the idea of things "not evolving much" should be clarified, too - it's a short-hand for not changing their general phenotype greatly over time (because of relatively stable general conditions in the environment). Evolution doesn't just stop, ever. Changes fluctuate constantly around a type that fits the environment well, responding to changes in bacterial infections, viruses and other parasites. At least, I think that's right.
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        Nov 22 2011: Yeah, I agree. I'm not sure on the exact dodo history but I'm sure we can wiki it. Still I think you got the general idea. :)

        Thanks! Crocodiles are another good example. They are top of the food order yet I doubt there life expectancy has changed "much" over the ages. There are always some challenges left like you pointed out. Disease, famine etc. Yet they've found some some sort of equilibrium with their enviroment. Maybe immortality is not possible without reverting to a infant state (like that Jellyfish).

        Maybe DNA damage from radiation etc. forces a species to "redo" it's DNA from time to time.
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    Nov 19 2011: Your question is problematic. Are you assuming that evolution will never solve the problem of aging?
    Or just asking why has it not happened YET?
    Your usage of the words NEVER and FOREVER is problematic as well.

    We are talking about LONGER life. And it might be "solved" by evolution in the near or far future. In fact, it is constantly being solved by humans - we are living longer now!!

    All your questions are made under the wrong assumptions about Evolution and life.
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      Nov 20 2011: we may be living longer medically but our genetic potential to live is barely different from cavemen. I would never propose it will or will not happen but it could happen.
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    Nov 19 2011: While longer lives might seem to be beneficial, especially for those who are enabled to enjoy them, but the consequences to the rest of the environment and other species will also play into the consideration. It also seems that now is an exciting time where we can use technology to overcome biological limitations. There is a way toward a more sustainable way of living. I think Eileen Workman's http://www.sacredeconomics.com/ can help create a framework in which evolutionary processes are irrelevant. Conscious processes and mutual aid for mutual benefit creating a better world for us all.
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    Nov 19 2011: If evolution moves forward by mutation & natural selection, then we should expect average ages to be increasing. Surely the person who lives longer produces more offspring & therefore increases his share of the genetic makeup of the population. Seems simple.
    The proviso is of course that evolution is occurring in the first place.

    :-)
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      Nov 19 2011: To live and stay alive depends on energy that drives it.
      Plants take it from the sun and animals from plants, you know.
      To be successful it is necessary to use that energy as efficient as possible.
      If you look at fishes you see species that produce hundreds of thousand eggs.
      Other species protect their eggs and can do with a few hundred.
      Some species protect the young also and provide food as the young swim free, they just need less than a hundred eggs. Then there are viviparous species that just get a few young at the time.

      So thinking in evolutionary terms is thinking about how to preserve energy. The only species that makes an exception is the human being. Humans thought that God provided all they needed and without limit.
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        Nov 20 2011: Hi Frans

        Surely then it is more energy efficient to evolve immortality than to continually reproduce. Given that creatures are continually replacing their cells anyway.

        What would be your argument against the principal of longer-lived creatures creating more offspring & therefore being more successful in the evolution stakes ?

        I think Anuraag makes a good point.

        It is interesting that both the bible & Gilgamesh (& no doubt others) tell of extended life spans in the past, which would mean that our lives are shortening in the long term.

        :-)
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          Nov 20 2011: If you "evolve immortality" then you end evolution. Evolution of species operates on the new combination of genes (the "genotype") that defines new individuals. Without new generations there would be no evolution. If organisms were immortal they would have to stop reproducing or their numbers would quickly overrun their resources.
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    Nov 19 2011: I feel that evolution hasnt seen the circumstances in human history to warrant the need to live longer. By this I mean the mass starvation, violence, environmental considerations that affect the human body, etc.. when we all start living in a peaceful coexistence and the body, over an extended period of generations, views longevity viable, then it might start happening. however based upon the history of the human race up until this point.. we are still centuries off. Although, it sounds like Kenyon is looking to bypass the necessary evolution cycle. Watch "In Time" with Justin Timberlake, playing in theaters now. It poses the question of a society where people could theoretically live forever (barring physical harm). Kind of neat. Not winning any Oscars... but neat none the less.
  • Nov 18 2011: Age is what strives evolution. Shorter lifecycles helps us evolve faster. What might seem as a disadvantage is actually a finetuned system to keep progress and life alive. We might beat this system - and see where that takes us. From a scientifical perspective i dont think everything must die - we can alter our destiny to some degree. But in a macroperspective i dont think we can ever alter the rules of progress. We can choose a path away from where natural evolution takes us. We will probably take that road. It¨s still just a road in a very complicated infrastructure. It¨s not a question about if rules are ment to be broken. We must realize that there are no rules that can't be broken if nature¨s not keeping us back. After we passed some mental barriers we will be where we dont think we will be today. But it¨s just food for thoughts. Apologizing for bad english. And most of all for bad theory. Eat it, kill it and make us progress.
  • Nov 18 2011: Thank God it never did, what would I have learnt without ageing? What would I be if I were to never age, never die, never face the black void of nothingness? Id be a bum! Id be a quitter and Id take everything for granted! Thank God for ageing, may it never cease to be.
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    Nov 18 2011: I think perhaps the underlying conceit here is that we have arrived at some state of perfection which we can know rest at..
    It's simply not true.

    Asking why Evolution hasn't solved the problem of ageing is like asking why capitalism hasn't solved the problem healthcare, education, social well-being, nutrition.. cos that's not what it's designed to do.. Why hasn't banking solved the problem of poverty and inequality.. Evolution is ageing. Worm is spice.. If you really want to live for ever you need to find a new mechanism.

    and again all that said we haven't started on cultural evolution, which maybe where we take off as a species and become less dependant on physicality.. but that's another topic and we're a long way of achieving it so let's discuss that if and when we get there..?
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    Nov 18 2011: the more I think about this question the less sense it makes.

    The basic metabolism of evolution is birth death and variation.

    We all know the phrase 'Survival of the fittest'
    Not the most accurate summary of the theory but not too bad and well understood.
    Well another way of phrasing it is 'Non-survival of the non-fittest'

    If the there is no death then there is no evolution as Gerald points out.
    Immortal being do not evolve (physically) so evolution will never produce them.

    It maybe that humans will develop techniques which allow us to live indefinitely
    but then we will have become a non-evolving species..

    The question is akin to 'why didn't evolution solve the problem of breathing out.?'
    we breath in to get oxygen.. we've got it now.. why go to all the trouble of breathing out..

    well we all know that 1. so we don't explode and 2. to eliminate toxins.

    well it's the same with death.. so the population doesn't explode and to get rid of the chaff..

    personally I don't think we will ever achieve physical immortality and I'm glad.. awful thought.
    This tinkering with chemicals and attempts to switch on or off isolated genes shows a naivety
    both in out understanding of how complex and subtle the information for body building is
    and also in out concept of what it means to be a sentient being in an organic body.


    Isn't an organism with a longer life and a longer sexual prime at an advantage?
    No.. because it's still only copying the same sets of genes..

    Or maybe breeding after a certain age would mean passing on damaged genes which would prove detrimental on the long run?
    it's not just about healthy or damaged genes it's about new combinations.. constant change to have as many variations as possible
    so you have more chance of one surviving and unknowable future..
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    Nov 18 2011: Some interesting points emerging from this conversation by the following.

    @Douglas Herz @David Hamilton: There are evolutionary advantages to having a shorter life cycle as it increases the opportunity for the species to adapt over more generations.

    So aging may be preferred but is it a requisite for an organism to compensate itself with aging and natural death?

    @Kevin Dewald: Only when the need to compete is eliminated from the equation (for example, by not having any more natural predators) and the environment is no longer a threat, natural selection can focus on developing anti-aging mechanisms.

    Is it that our metabolic processes are over-compensated for selective advantages in their sexual prime which prove detrimental for longevity?

    @In Cyril Germain Article:
    @Alfred Rusell Wallace "when one or more individuals have provided a sufficient number of successors they themselves, as consumers of nourishment in a constantly increasing degree, are an injury to those successors. Natural selection therefore weeds them out."

    @Leonid A. Gavrilov and Natalia S. Gavrilova "Many manifestations of aging happen after the reproductive period of evolving organisms at ages which are beyond the reach of natural selection."

    @Jose Luis Soto Vázquez @Aubrey De Gray: "Aging is not a product of selection, evolution; aging is a product of evolutionary neglect. We have aging because it's hard work not to have aging".

    Is it that genes leading to long lives and short lives with better reproductive advantages have been mixing indefinitely that natural death is imperative?

    Isn't an organism with a longer life and a longer sexual prime at an advantage? Or maybe breeding after a certain age would mean passing on damaged genes which would prove detrimental on the long run?
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      Nov 18 2011: Not long ago anthropologists found out that the aging of human ancestors changed at one point in time.
      It had almost been somewhat below 40 and suddenly it became 60 years. For the same period there was found an increase of tools and cultural activity.
      The idea arose that the longer grandparents took part in parenting the more energy the parents could put in providing. And even more important, the grandparents could teach their grandchildren which gave a boost in development.
      People that lived longer were more succesful and outnumbered those that didn't.
      So if we can arrange it that those that reach hundred years can benefit to the survival of their great grandchildren we humans will all reach that age after maybe 10 or 20 generations.
  • Nov 18 2011: It has. Natural selection has selected for itself. For if everyone lived forever, there would be no natural selection and species would not adapt and improve.

    Use this thought experiment. Take a population of animals, half of which live forever and half of which live shorter lives. Which ones will adapt to changes in the environment more quickly? For example, let's say temperatures became colder, killing most of the animals except those who were adapted to the cold, say those with more hair on their bodies. Those that survive and reproduce will have some offspring with even thicker coats of fur, and of those that survive even thicker coats over multiple generations. We will be selecting for thick coat, but also for evolution itself. There will thus be a balance between shorter life span to adapt quickly to changes, and longer life span to have more offspring. There is probably some sort of optimal age for each species.
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      Nov 18 2011: So aging may be preferred but is it a requisite for an organism to compensate itself with aging and natural death?
  • Nov 18 2011: Aging is not a problem it is the mechanism that evolution uses to advance a species toward an improved form. If no one died survival of the fittest would be robbed of its selection criterion. I'm sure that nature must have tried immortality at some point and was stopped in it's tracks when the creature exhausted all available resources and became extinct.
  • Nov 17 2011: The one i know about is tied to Darwinian evolution, and I don't see the point to try to explain it, as other peoples did it nicely. (http://www.psychologytoday.com/blog/adventures-in-old-age/200903/problem-darwin-why-do-we-age-and-die-rather-live-forever )

    Also there is a jellyfish that revert to polyp after being sexually mature, which makes it immortal in theory (only in theory, as one jellyfish would need to escape deaths/predation for ... well, quite a long time).
    (http://en.wikipedia.org/wiki/Turritopsis_nutricula)