Wikipedia’s article on the matter is excellent. I mean it literally, it is a very good wiki article compared to other wiki articles, and a very, very good article compared to other articles in general.
For a critical essay on human races, see Confusions About Human Races by R.C. Lewontin. And see Human genetic diversity: Lewontin’s fallacy by A.W.F. Edwards for a refutal of that. Note that the refutal is pretty hard to understand without prior knowledge of statistics and genetics.
Lewontin is quoted in Edwards abov as riting:
”It is clear that our perception of relatively large differences between human races and subgroups, as compared to the variation within these groups, is indeed a biased perception and that, based on randomly chosen genetic differences, human races and populations are remarkably similar to each other, with the largest part by far of human variation being accounted for by the differences between individuals. Human racial classification is of no social value and is positively destructive of social and human relations. Since such racial classification is now seen to be of virtually no genetic or taxonomic significance either, no justification can be offered for its continuance” (my emfasis)
is falt out rong. If one takes a look at, for instance, Categorization of humans in biomedical research: genes, race and disease by Neal Risch1, Esteban Burchard, Elad Ziv, Hua Tang, it is clear that racial classifications ar useful for medical purposes. And it shud be clear that being able to better help people medically is of ”social value” (Lewontin’s frase).
Based on reading these texts and others, it is my view that ther ar significant genetic differences between different populations of humans (15%ish), and that these differences ar relevant to som traits (such as intelligence and skin-pigmentation). But also that most (85% ish) of the variation of genes in humans is within groups. Based on this information, one wud expect most human traits to overlap greatly, wich is also wat intelligence (a human trait) reserchers find. (See the pictur on this wiki article.2)
Notes
1Here is an interview of him, interesting fellow.
2And if anyone nos how to calculate how large an area on the graf is shared by the two functions (normal distrubutions), let me no!