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Why makes organisms reproduce?

I don't mean to linger on the philosophical point of this question but more on the biology of it.
In species other than humans and a few others, sexual reproduction is not something done for pleasure so why do other species do it? It provides no benefit for that particular organism. Many people have answered that it's just a passed down trait or it has to do with genetics. I don't understand how a habit can be passed down through genetics. This isn't something like the need for an organism to feed itself, because in that situation, the organism would die otherwise. With sexual reproduction, there is no benefit (that I can see) for the organism.
Which leads me to another question: why do females (of species other than humans, once again) find males with better reproduction rates, more 'attractive' (as I have learned in my biology class). It doesn't mean higher survival rate, so once again, how would that organism be affected and how does it make that decision?

  • Apr 17 2013: If you'd like an explanation (in terms of biology), then Nick Lane's book 'Life Ascending' attempts (quite well) to explain why and how sexual reproduction evolved. His book details 10 great 'inventions' of evolution, with sex being one of those inventions. It's worth a look to get some detail about evolution.

    This is a small sample of an article he wrote in 2009:
    "Sex is absurd. It costs a small fortune to find a partner, transmits foul venereal diseases and parasitic genes, and randomises successful allele combinations. Worse, sex requires males, viewed by implacable feminists and evolutionists alike as a waste of space. Why we all have sex anyway was seen as the queen of evolutionary problems in the 20th century. Recent work shows that over time all complex species would degenerate, like the Y chromosome, without sex. The details help explain why sex first arose, enabling early eukaryotes to thrive."

    As others have said, sex is costly to the individual but beneficial to the species. As I understand it, mixing genes gives an organism a greater chance of survival, so any species that does that will have an advantage over a species that doesn't mix genes (via sex). So once sex evolved, it provided an advantage to those species that did it t reproduce. Also, something that I understand is important is that sex evolved very early in the history of life (with early eukaryotes). I'm no expert, but Nick Lane is (and it's just a short chapter in a good book!).
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    Apr 16 2013: For the benefit of the organism?
    Not so. Organisms only last a generation, whether they've been "successful" or not. There is no selection going on.
    Selection happens at the gene level. THEY go down generations. So whatever organisms do, they do not to benefit themselves but to benefit their genes (i e to cause the genes to replicate).
    About female selecting males. The genes present in a given female exist because they have been successful. So if such gene caused the female to be attracted to such feature in the male, then it's probably still there.
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    Apr 16 2013: Is your question "What" makes organisms reproduce. Or perhaps you are asking about "Why" do orgamisms have sexual activity? Then again I read your comments and wonder if you mean what are the stimuli that invite sexual activity.

    I am guessing that this is a result of a science class assignment.

    Your last question is more straight forward. In the animal world the males fight for supremacy to rule over a herd. I do not think it has to do with "attractive" but more with dominance. Two things occur: 1) rut: when the males go into a reprodctive phase with the members of the herd. 2) Female come into "heat" the period of time which they are most receptive to reproduction. This may include dances, scents, and various means of alerting the male.

    As for humans .... no one is smart enough to answer that question. If anyone tells you they can tell you what make each of us tick .... beware. We are each individual and respond differently.

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    Apr 16 2013: Your answer lies in the philosopy arena, not in biology. If you ignore the transcendental, the supernatural, you will not discover the root cause which explains why living things reproduce.
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    Apr 16 2013: I'm sure there is something in the DNA or pheromone-related processes of these species that is, if not for pleasure but purely instinctual, in them and reproduced in their offspring in order to continue the species. Extinction is not a "normal" or typical process, for example, we do not have species becoming extinct very often. So obviously there is a mechanism (sort of reiterating your point here) in each organism (including the asexual ones, something to consider there) that provides for a continuation of life.

    The same general idea could be applied to females finding males with high reproductive or pleasant parental factors more attractive in that we are genetically, historically, as a species drawn towards living life, creating life and passing onto those we love the parts of ourselves that we find wonderful. Fear may also play a part in the desire for a strong reproductive mate, as the fear of death and the sought out preservation of self, and in turn species, has always been present in the human race. The same probably goes for the other kingdoms as well.
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    Apr 16 2013: It all revolves around survival.

    More survival = pleasure, less survival = pain

    more money = more survival

    more attractive = more survival