Evolutionists, a question as to where on the http://www.talkorigins.org/ site this is?

Question

What is the link within it that explains how the different sexes formed, and why they formed from being either both sexes, or from a-sexual to having to sexes?

Sorry, two sexes, not to sexes

Cool, ok, thanks, i was just wondering, but thanks for being honest

cool, thanks secretsauce. Wouldn't asexual be better in evolution? I mean, in terms of evolving further no, but it's safer, if there's only one of you left, then you can keep the species going, yeh?

Lol, yeh, i can understand that. It's safe to stay in a concrete reinforced bunker for your life, but getting out there is better for you in the long run :)

with cmw, would not interbreading of a species create the same species, but interbreading of different species within the same *kind* i think it is, is that what would create new creatures? Or am i confused about species and kinds too (confused)

Answer 1

Here you go:
http://www.talkorigins.org/indexcc/CB/CB350.html

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>"Wouldn't asexual be better in evolution? I mean, in terms of evolving further no, but it's safer, if there's only one of you left, then you can keep the species going, yeh?"

Yes. I think you hit it on the head. Sexual reproduction is really good for evolving further (it generates a *lot* of stable variation very fast), but in an *extreme* crisis (only one individual left), asexual is "safer" for survival.

But "safer" isn't *always* better. If the species is doing well, and there are plenty of mates around, then sexual reproduction is good at generating new individuals, and the species is able to adapt quickly to changing (or new) environments. The reason it's a 'safe' environment for this is that every new offspring can be a genetically complete individual, while also being a genetically unique individual ... different from either of its parents, or any of its siblings.

Asexual reproduction only produces clones ... so if some environmental change (like the arrival of a new disease) becomes bad for one individual, it becomes bad for *all* individuals ... the only source of new genetic material is mutation, which is not very reliable. That's why asexual reproduction works well for single-celled organisms (like bacteria or algae), that reproduce fast and in *enormous* populations ... this keeps the mutational rate fast enough to keep up with changes in environment (even to the point where they can keep up with the antibiotics we keep throwing at them) ... but is not really great for dramatic evolutionary changes, and is inefficient for larger multi-cellular organisms.

And over the long run sexual reproduction gives larger multi-cellular organisms a safer environment for generating lots of new species (cladogenesis) ... which becomes self-perpetuating ... that's why there are so many sexually reproducing species.

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The above was just regarding your followup w.r.t. the origins of sexual reproduction. As for the development of two dedicated sexes (which came much later), see my answer to this question:
http://answers.yahoo.com/question/index;_ylt=AiEjOVknmXZfd7JBpVD4nIDty6IX?qid=20070828072255AA00yDE&show=7#profile-info-Cma50tw2aa

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cmw ... a hypothesis is not evidence. A hypothesis is an *explanation* (which is what the asker requested).

>"...When I objected, he told me I don't know what a species is."

Seeing as you don't even know what a "hypothesis" is, or the difference between "evidence" and "proof" ... that sounds pretty likely that you don't know what a species is.

... Actually, I just checked the post you are referring to. You wrote: "Yeast is yeast. Flies are flies." ... So that guy was right ... clearly you do *NOT* know what a species is. Hint: there are over 1,500 known species (yes *species*) of fruit flies *alone*! There are between 85,000 to 120,000 known species (yes *species*) of flies.

Sorry ... I'm not trying to be mean. But you have clearly formed an opinion about a *basic* concept of science, based on a really faulty understanding of even the *basics* of science (like what "hypothesis" or "species" means). This leaves you vulnerable to believing creationist sites run and written by evangelists with little or no actual science education, who claim to understand science better than the scientists ... who claim that the entire scientific community is ridiculously, stupidly wrong *about science*.

This willingness to believe these sites comes from the unfounded belief (reinforced by these creationist sites) that evolution=atheism ... and so you (understandably) look for any argument, valid or not, for rejecting evolution because you think that by doing so you are affirming God. But this is a false choice being sold to you by the creationist sites.

Disagree with evolution if you want ... but at least do it from a position of real understanding. Don't *just* get your info. about evolution from the creationism-hawkers. You wouldn't just learn about religion only from die-hard atheists, would you? So why learn about evolution only from die-hard anti-evolutionists?

Evolution is NOT atheism. (I am not an atheist.)

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P.S. crazy_ivan ... I really like your bunker analogy. It's exactly right. Asexual reproduction is safe, but not very creative. .... And not nearly as much fun. :-)

Answer 2

This is currently a major puzzle in evolution.

We know why sex was successful (it helps generate successful mutations more rapidly than asexual reproduction, allowing a species to evolve quickly in response to environmental changes), but we don't know exactly how it began.