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Anuraag Reddy

AIESEC India

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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.

Topics: aging evolution
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  • 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.

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