Race has a biological basis. Racism does not.

The human genome records that natural selection has been regional, meaning that a largely different set of genes has changed under evolutionary pressure in each race. This is just what would be expected given that the populations on each continent have responded to different local challenges. Some of these selected genes are active in the brain, though with unknown function, confirming that the brain is no more exempt from evolution than is the body.

This raises the possibility that human social behavior has been shaped by evolution just as the body has been. Humans being a highly social species, social behavior is critical to a society’s survival and hence likely to be a prime target of natural selection.

For instance, the first settlements appear only 15,000 years ago; for the previous 185,000 years we existed as small, mobile bands of hunters and gatherers. Was the long delay in settling down because our ancestors couldn’t figure out the advantage of putting a roof over their heads? It seems more likely that a change in social behavior was required to live in large, settled groups, and that it took this long to evolve.