Lack of Human varieties. Genetic "cleansing" through history?

Well, the fact that they're not here now would seem to suggest that they were, indeed, killed off.Or did you mean by homo sapiens? That's possible, sure. Going from a question in the first post, what makes you think that doesn't constitute a kind of evolution?

No, extinction is part of evolution. Look in the fossil record - over 99% of the species we know from fossils are completely extinct. Extinction is largely the ultimate destination of any one species, so I'd say that's definately part of evolution. There's no such thing as a "gradual mutation." Mutations are basically instantaneous.

Again, species don't mutate. Genes mutate. Species evolve; when they become new species, that process is called "speciation" and it can indeed be gradual. It can also be sudden.

Like CS said, that's exactly what you're talking about. "Environment" doesn't mean "the scenery", it refers to the area where you live and the other creatures that inhabit it. Organisms adapt to things like predation and disease - other creatures - as much as they might adapt themselves to hot or cold climes. These aren't ethnicities we're talking about, though. These aren't two different races of Homo sapiens; these are two different species that may or may not have even been interfertile. Well, I'm not sure the jury isn't still out on that. A lot of the studies have been criticised for a biased methodology where anytime human DNA is detected in Neanderthal samples, it's assumed to be sample contamination from handlers and excavaters. If that assumption is erroneous then the studies might be throwing out genuine human sequences in Neanderthal DNA by mistake. Not likely, but possible. I don't even know for sure how you would tell the difference between lab contamination and actual Homo sapiens sequences in N. DNA. They were probably out-competed for resources, if not outright killed in interspecific warfare. I agree with you that hypotheses that N. "blended in" to our gene pool are speculative at best and supported by little to no evidence.

I have no idea what you're talking about, here. If you expect me to be able to draw the precise line between evolutionary determinism and personal initiative, you expect far too much from an internet forum.The fact is, Hitler's genocide had a measurable effect on the gene pool. We can examine it in evolutionary terms because it resulted in a change in allele frequencies. Does that mean than I'm sweeping the crimes of the Holocaust under a scientific rug, or trying to let Hitler off the hook? Of course not. Don't try to bait me or paint me as some kind of anti-Semite. No idea what you're talking about, still. "Inferiority" has no meaning in regards to biology. Just the observation that genocides don't occur because people are threatened, but because people are made to believe that they are threatened as a pretense to sieze the resources of another group. Look to the Sudan, to Darfur. What do you think the ganjaweed are after? They're not slaughtering a defenseless people because they fear them; they're slaughtering them in order to take their lands, livestock, and whatever else they want from a people it was convinient to get people to regard as some kind of threat. Still no idea what you're talking about here. "Weak in biological terms"? What does that even mean? What's your objective measure for "weakness"?Suppose we had a competition between Ewoks and allosaurs. Any one Ewok is no match for any one allosaur - the allosaurs have the superior strength, endurance, and ferocity - but many Ewoks can work together to build traps, leverage natural forces like gravity, and steal technology from the Rebel Alliance. No group of allosaurs can do the same thing no matter how many of them there are - they don't even have the forelimb stregth to manipulate their environment.Who is strong and who is weak? These words have no meaning in biology. Who is the more fit? Well, that depends on who wins. If the allosaurs wipe out the Ewoks, the allosaurs were clearly more fit. If the number of Ewoks comes to exceed the number of allosaurs, it must have been the Ewoks that were more fit. If your buddy has 20 kids that survive to adulthood, and you have 2, your buddy is more fit than you, no matter the fact that you work out at the gym and he sits on his butt and eats Cheetos. Still have no idea what you're talking about. I have a brain but it doesn't allow me to violate the laws of physics. It simply allows me to think ahead and use language. Well, there is some evidence to support it, like the lack of any "Neanderthal battlefields" or anything. And how did Homo sapiens kill off a species with a larger brain, bigger muscles, and possibly more developed culture in the first place? The idea that Homo sapiens extinguished the Neanderthal isn't immediately obvious. The idea that we simply merged genes with them is still plausible if the studies that claim no Neanderthal DNA are inconclusive. Probably not correct, but still plausible.