After my post on the race question I thought it would be useful to point to Jerry Coynes Are there human races?. The utility is that Coynes book Speciation strongly shaped my own perceptions. I knew the empirical reality of clustering before I read that book, but the analogy with species concept debates was only striking after becoming more familiar with that literature. Coynes post was triggered by a review of Race?: Debunking a Scientific Myth and Race and the Genetic Revolution: Science, Myth, and Culture. He terms the review tendentious, and I generally agree.

In the early 20th century Western intellectuals of all political stripes understood what biology told us about human taxonomy. In short, human races were different, and the white European race was superior on the metrics which mattered (this was even true of Left-Socialist intellectuals such as H. G. Wells and Jack London). In the early 21st century Western intellectuals of all political stripes understand what biology teaches us about human taxonomy. Human races are basically the same, and for all practical purposes identical, and equal on measures which matter (again, to Western intellectuals). As Coyne alludes to in his post these are both ideologically driven positions. One of the main reasons that I shy away from modern liberalism is a strong commitment to interchangeability and identity across all individuals and populations as a matter of fact, rather than equality as a matter of legal commitment. In a minimal government scenario the details of human variation are not of particular relevance, but if you accept the feasibility of social engineering (a term I am not using in an insulting sense, but in a descriptive one) you have to start out with a model of human nature. So this is not just an abstract issue. For whatever reason many moderns, both liberals and economic conservatives, start out with one of near identity (e.g., H. economicus in economics).

I want to highlight a few sections of Coynes post:

What are races?

In my own field of evolutionary biology, races of animals (also called subspecies or ecotypes) are morphologically distinguishable populations that live in allopatry (i.e. are geographically separated). There is no firm criterion on how much morphological difference it takes to delimit a race. Races of mice, for example, are described solely on the basis of difference in coat color, which could involve only one or two genes.

Under that criterion, are there human races?

Yes. As we all know, there are morphologically different groups of people who live in different areas, though those differences are blurring due to recent innovations in transportation that have led to more admixture between human groups.

Why do these differences exist?

The short answer is, of course, evolution. The groups exist because human populations have an evolutionary history, and, like different species themselves, that ancestry leads to clustering and branching, though humans have a lot of genetic interchange between the branches!

More here:
Jerry Coyne on race: a reflection of evolution | Gene Expression