Racism and discrimination are wrong as a matter of principle, not of science. That said, it is hard to see anything in the new understanding of race that gives ammunition to racists. The reverse is the case. Exploration of the genome has shown that all humans, whatever their race, share the same set of genes. Each gene exists in a variety of alternative forms known as alleles, so one might suppose that races have distinguishing alleles, but even this is not the case. A few alleles have highly skewed distributions but these do not suffice to explain the difference between races. The difference between races seems to rest on the subtle matter of relative allele frequencies. The overwhelming verdict of the genome is to declare the basic unity of humankind.
Human evolution has not only been recent and extensive, it has also been regional. The period of 30,000 to 5,000 years ago, from which signals of recent natural selection can be detected, occurred after the splitting of the three major races, so represents selection that has occurred largely independently within each race. The three principal races are Africans (those who live south of the Sahara), East Asians (Chinese, Japanese, and Koreans), and Caucasians (Europeans and the peoples of the Near East and the Indian subcontinent). In each of these races, a different set of genes has been changed by natural selection
This is just what would be expected for populations that had to adapt to different challenges on each continent. The genes specially affected by natural selection control not only expected traits like skin color and nutritional metabolism, but also some aspects of brain function
Human social structures change so slowly and with such difficulty as to suggest an evolutionary influence at work. Modern humans lived for 185,000 years as hunters and gatherers before settling down in fixed communities. Putting a roof over one’s head and being able to own more than one could carry might seem an obvious move. The fact that it took so long suggests that a genetic change in human social behavior was required and took many generations to evolve.
The various races have evolved along substantially parallel paths, but because they have done so independently, it’s not surprising that they have made these two pivotal transitions in social structure at somewhat different times. Caucasians were the first to establish settled communities, some 15,000 years ago, followed by East Asians and Africans. China, which developed the first modern state, shed tribalism two millennia ago, Europe did so only a thousand years ago, and populations in the Middle East and Africa are in the throes of the process.
