@thltd_: Human races are separate *sub*...

Human races are separate *sub*species as per the criteria used to classify every non-human animal species on earth. In The Descent of Man, Darwin wrote that if we classified by morphology alone (which we don't), Blacks and Whites would be recognized as separate species.

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Subspecies = two or more populations within the same species that have become phenotypically distinct from one another (due to geographic or ecological separation and divergent evolution), that can successfully interbreed to produce fertile offspring but generally avoid doing so.

The typical answer is one but if you look at admixture analyses of canid species and humans, at k=6 the canid "species" show similar levels of overlap to human "subspecies." There's still a lot of debate over how to properly define a species.

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Maybe looking at K=5 would be more appropriate for the canids, since the authors of this paper divided them into five major population groups, but the genetic overlap is there either way. Among humans, K=6 corresponds to the six historically recognized "major races."