Evolution and complexity

This might just be a nitpicky, or maybe you did just use poor wording, but: I can't see this as being true.Selective pressure varies on different populations so that some have felt more pressure and changed more. Couldn't you call that more evolved?Think about whales compared to aligators. Whales went from sea to land and back to sea again while gators have been lying in the same ol' swamps fairly unchanged. Couldn't we call the whale more evolved than the gator?

No, I was saying that the pressure causes the change and that the change is evolution.More pressure does lead to more change - when the mutations are there - so I do think that more pressure means more evolution. Heh. When I read that you wrote that all things have experienced the same amount of evolution, I was going to ask how you quantify evolution to know that its the same I'm not considering the "amount" of evolution to be the length of time that the species has been evolving. I see the "amount" of evolution as the amount of change that a species has undergone. Since some species have changed more than others, I'd say that they all have NOT had the same amount of evolution. How so? I don't think I was ignoring that. I had it in mind, at least. And it was part of the point. Gator's evolutionary history is different from whales. Whales have changed more. I don't think it matters when the adaptaion has occured, its about how much adaptation has occured.

Not neccessarily.A speciation event usually occurs when the two populations become isolated. The new species doesn't always replace the old one.However, when a species is gradually evolving, it is constantly replacing the old versions of itself. This isn't a speciation event though.For example, take one population of sheep. Have a flash flood that produced a river that divides them that they cannot cross. Over time the two populations will be different from each other. When they become so different that they cannot interbreed genetically (not because of the river) then they have become two seperate species, but one did not replace the other.If we have one population of sheep that is changing over time and at some point in time it is different enough that it would not be able to reproduce with what it was a very long time ago, it is a new secies that has replaced the old one. We just have one contiuous population instead of the two.Make sense?

I'm just disappointed that you beat me to it I actually read the "sheep and river" story in a biology textbook, IIRC.But, yeah, that's the 'official' example that you, and I, see tossed around everywhere.

Thanks for the excellent and detailed explanation. Yeah, I wasn't really considering that. I probably should have typed that more pressure can mean more evolution and not that it neccessarily does. But it isn't important for my original point in Message 5:

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Selective pressure varies on different populations so that some have felt more pressure and changed more. Couldn't you call that more evolved?

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What do you think?And what do you think about Crash's statement:

You're in the right place. On the Origin of Species, by Charles Darwin lol