Single-celled life is arguably the most resiliant life on earth. Some say it can survive in outer space.
Multicellular organisms can fill higher level niches unreachable by bacteria. For starters, the first multicellular organisms could eat the unicellular guys.
Why would sexual reproduction develop?
Gene transfer is common among all organisms. Bacteria transfer plasmids on a regular basis. Sex in higher organisms is more costly but has definite advantages over asexual reproduction. It seems to be a powerful mechanism to stay one step ahead of infectious microbes.
I've heard better reasoning from a football fan saying how his 0-7 team can still be expected to make the playoffs.
So youre a Detroit Lions fan? ;)
Then there is the lack of evidence. I can perfectly accept that tigers and housecats share a common descendent. I can't accept that housecats and horses do.
The genetic evidence alone shows a tremendous interrelatedness between all known life forms (humans share a number of genes with bacteria). Even the same genetic mistakes are found within related species.
And then there is irreducible complexity.
IR turns out to be a flimsy house of cards. Gene manipulation experiments have been a disaster for Behes argument most parts do not appear to be absolutely essential for function. Also there are a number of excellent models for how various seemingly irreducibly complex systems could have evolved step by step. The evolution of the eye is thought to have occurred independently a number of times.
Then there is a religious aspect. No offense meant to anyone on this thread, but there are those who use evolution as an excuse to deny God's existence.
I very much stand with you here, but so far I havent seen too much of this attitude on these threads (it certainly isnt the majority opinion held by people who accept evolution.)
Correct me if I am wrong but I see it the other way,
Creationist: If one can somehow disprove evolution, then God MUST exist.
It seems to me the position taken by those of weaker faith.
Care to back it up? I bet you do not. You only find that garbage in TalkOrigins.
Another blatant lie. No one in the over a dozen years since he first proposed it has been able to show that the bacterial flagellum is not irreducibly complex. And BTW, no one, least of all Darwin, has ever shown that the eye is not irreducibly complex either. However, I have shown, quite clearly that the developmental process of an organism is a program and hence not subject to random evolutionary stochastic alteration.
No, but I grew up with the Eagles, which was once almost the same thing. ONCE, you know. :-)
Creationist: If one can somehow disprove evolution, then God MUST exist.
There could be. It's not my view. I think I can trace my skepticism in evolution to my school days, when I was taught (uncritically) that the development of life began with abiogenesis (albeit it wasn't called that) followed by a poorly presented explanation of evolution --which I accepted until much of what I was taught was shown to be untrue, even falisfied.
Added to that was a strictly enforced ban on any mention of the Creator.
I suspect if they were to allow the Bibles back, and some innocuous prayer and some Christmas carols, much of the hostility in this debate would go away (along with a lot of other social pathologies.).
On the other hand, I sometimes think that if I went to a strictly religious school and all mention of evolution was banned, the odds would be good that I would be a raving atheist. So there is a line which must be walked.
I guess I'm not really as much of an anti-evolutionist as I sometimes think, although I'm very skeptical of common descent, and I think the unguided development of life is ridiculous idea.
Another point. I think there are a lot of holes in the theory. If they are filled and the theory is found to be solid, that's a good thing. If they can't be filled, however, it is even more important to understand that. A skeptical attitude -- by which I don't mean a ban on its teaching, or research or a doctrinarial approach that it must be wrong -- towards evolution might go a long way in furthering our knowledge.
It's late and I'm starting to ramble. Thanks for the answer.