(02-13-2009 04:40 PM)NIU007 Wrote: Well, I'm talking about animals (plants, etc.) changing over time in response to the environment, animals with certain variations becoming more successful than and outcompeting others due to random mutations that provide a survival/reproductive advantage. This is probably not an evolutionary biologists's definition. I'm just trying to get an idea of what it is you think isn't occurring. For the moment I'm referring to relatively minor changes, not whether fish can eventually turn into giraffes or something.
Ok, but even in your first sentence you have 2 definitions. Animals changing or populations changing.
Animals changing? Yes, in a Lemarkian demonstration, animals can change, at least according to the Newsweek column I posted. I'm not sure this has been fully explored, or what it even means. Do we have newer species? Or just different gene expressions? Even species is hard to define, as there are examples where a M+F of two 'species' produces fertile offspring, while a F+M combination does not.
And even if it's a different species, how does that percolate up the taxonomic charts? When do we get different geni, families, and classes? And scads of other questions abound (who do you breed with when you're a new species?)
And the whole gene expression phenomenon is HUGELY IMPORTANT, but barely studied to date at all. Did you read about the 3 undersea creatures that were recently recognized as one species, but they had thought them three species for a century b/c the female, male and immature versions were so radically different?
Now, as to the populations changing, sure, that happens too. So what? I mean it is important for various reasons, from the health of a population to the interplay of local biosystems. But, it's not really "evolution" in terms of origin of species.
In the end, yaks still produce baby yaks...and no model based on scientific materialism exists to tell us where the first yaks came from.