If race is defined as a breeding population (gene pool), there are different human races because the human species is not a single panmictic population where mating is random, i.e. there are barriers to gene flow: "In almost every species, the number of individuals is so great that the species population is widely dispersed and subdivided into a number of breeding populations or demes." (David J. Merrell, The Adaptive Seascape: The Mechanism of Evolution, 1994) A breeding population (gene pool) is defined as "a group from within which mates are typically chosen" (John H. Relethford, Human Population Genetics, 2012) and because these groups of individuals having higher in-group mating than out-group: there are different frequencies in genes between breeding populations. I've noticed that in some population genetics literature, a breeding population is synonymous with race. This was not though the traditional definition, and "race = breeding population" only came into usage after the modern evolutionary synthesis (1950s). Rather than abandon the concept of race, geneticists and biologists re-defined it in terms of population genetics (Dobzhansky, Mayr, Simpson etc.) Clearly human races exist if they are breeding populations, and there are thousands of them (they more or less map onto ethnic groups). The problem though is a "mismatch" where traditional racial groups like "White" "Black" or "Mongoloid" are not gene pools per se but arbitrary groupings of hundreds of them: "The majority of human population geneticists and biological anthropologists, though they reject the race concept because of the arbitrariness of racial divisions, are prepared to divide the entire human species into more-or-less discrete panmictic units or demes despite the extensive continuities in breeding patterns and allelic distributions that exist. Biological anthropologist Jonathan Marks, for example, rejects the “typological” division of humans into a small number of discrete races because, circling the globe, one finds that traits are distributing continuously. He argues instead that it is the “small biopackages” called populations, not races, that are the “real units of human diversity” (1995: 274, 116). Similarly, human population geneticist L. Luca Cavalli-Sforza treats panmictic populations as real but characterizes attempts to classify “clusters” of populations into races as a “futile exercise” (Cavalli-Sforza, Menozzi, and Piazza 1994, 19)." (Gannett, 2003) Here we also have a semantic dispute. Some biologists don't think it is wise to call a breeding population a race. Your thoughts?
Why I am against defining a breeding population as a race: 1. Semantics: why not just calling them breeding populations? This was Ashley Montagu's argument in 1962: "Why call such populations 'races' when the operational definition of what they are is sharply and clearly stated in the words used to convey what we mean, namely, populations which differ from one another in particular frequencies of certain specified genes? Surely, to continue the use of the word “race” under such circumstances is to exemplify what A. E. Housman so aptly described as “calling in ambiguity of language to promote confusion of thought” (1933:31)." ("The Concept of Race". American Anthropologist. 1962. 64[5]: 919-928) 2. Mismatch: breeding populations do not match traditional or "ordinary" races: "Sarich and Miele (2004, 172) judge that the Dogon, Teita, and Bushmen (their terms) are distinctive races... Of course, Sarich and Miele are entitled to use the word 'race' however they want. But their central and explicit aim is to vindicate the ordinary concept of race, and so they cannot soundly replace ordinary race-talk with some other kind of talk." (Glasgow, 2009)
