Evolution Simplified

I see that this is an old thread, but it has been briefly been referenced in a new threadI haven't read through all of the replies here, but I want to challenge the original post:

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7. Conclusion: A corollary of 6 is that as generations pass, the number of organisms with "good" traits will increase, while the number of organisms with "bad" traits will decrease, until eventually all individuals in the species will have the "good" trait and the "bad" trait will disappear altogether.

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10. Conclusion: From 7, 8 and 9 we can conclude that a species will slowly "improve" with time, as new helpful traits appear and as the organisms with these traits are better able to survive and produce offspring with these traits.

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These two conclusions are not entirely true, and do not follow from the previous facts. The further conclusion to 7 and 10 is that evolution would lead to "perfect" species. This sort of reasoning led to the eugenics movement. This reasoning is simply not true- often evolution is quite happy with an organism that is just good enough to survive. Points 1-6 only say that evolution selects towards organisms that are good at surviving, not good at living in general. If an organism is good enough to survive, it survives- there is not neccessarily a trend towards perfection. Take vestigial structures as an example of a "bad" trait that hasn't dissappeared. I'd really rather not get into a debate about whether vestigial structures will eventually dissappear but haven't yet, I just want to point to the fact that the road of evolution accomodates neutral appendages.Another related problem- it is hard to define a "good" trait that is not relative to an organisms environment. Granted, there are some, like a functioning heart, but those traits are relatively fixed. Many changes we observe in organisms are caused by response to environmental factors. An organism changes environments, and the list of "good" traits changes. Organisms do not become "better," just more adapted.This point is more than semantics, thinking about good or bad structures is really inconsquential to many evolutionary arguments, and often leads to misunderstanding about evolutionary predictions. Species adapt, its important not to think of those adaptations as good or bad, they simply are changes in an organism that lead to speciation.

Thanks Chiroptera, I think my issues are pretty much resolved.Kuresu, my problem was exactly that good and bad can have moral and absolute meanings, whereas when they are used in evolution, they have a very conditional meaning, which as you say, depends on the environment. I was simply worried that this distinction was not clear in the original definition, but I guess the quotes sort of make up for the ambiguity.