In The Selfish Gene, Richard Dawkins argued that it is not species that compete, not even individuals, but genes. You'd never learn it from Dawkins, but it appears selection happens at all sorts levels, not just at the gene level. In Haidt's Righteous Mind, he (a psychologist) gives the following example of group selection.
A geneticist worked with cages containing twelve hens each, and he picked the cages that produced the most eggs. Then he bred all of the hens in those cages to produce the next generation. Within just three generations, aggression levels plummeted, and within 6 generations death rates fell from 67% to 8%, and eggs produced jumped from 91 to 237. If you just picked the hens that laid the most eggs, they tended to be the meanest, and so aggressive behavior (and dead hens) went up. That is group selection working better than individual selection, and gene selection is even less relevant; there is selection of genes, but only at the level of the group.
Then there's Steven Jay Gould's famous statement that 'there's been no biological change in humans in 40k to 50k years.' Haidt notes no one believes that anymore, especially after this Russian guy, Dmitri Belyaev, turned wild foxes into harmless dogs in only 30 generations, or about 600 years in human terms. That means the invention of agriculture 8k years ago could have really changed our brains and behavior at least as significantly as how foxes differ from dogs. It follows pretty basically that human races are probably truly different at some levels (mainly similar, to be sure).
These aren't minor changes. You have to pick this stuff up on the periphery, in blogs like gnxp, or books by Cochrane and Harpending, not the mainstream evolution books, which tend to focus on refuting intelligent design and creationists.