Anyone claiming it is a "social construct" is about as skeptical as John Edwards.
It is almost surreal for me to even have to make an argument that an Eskimo is not a Pygmy and that a Masai is not Aboriginie.
Yes, but none of those are "races." In fact, to most people a Masai anda Pygmy are the "same" race (both "black," "negro," or whatever), despite the fact that they're probably genetically more distinct from each other than a Japanese is from a Finn.
I will grant for the sake of argument that humans can be grouped into genetic clades. (Actually, that's probably not true -- there's enough intermixture that it makes it very difficult to do such grouping. But there do seem to be moderate-sized groups that are relatively uniform. So, as I said, I will grant the existence of clades.) These "clades," however, tend to be relatively small -- no larger than a few million at most and often far smaller.
The problem is that there is no rational way to group clades into anything that sensibly looks like "races." The "Finns," for example, might form a clade, as might the "Icelandic" and the "Japanese," and the "Australian Aboriginal" and the "Tasmanian." The question becomes how to put them together. Most people would like to group the Finns with the Icelandic as part of a "Nordic" or "White" or "Aryan" race. The problem is that those larger scale groupings quickly collapse under analysis; two relatively closely related groups will be in different "races," and two entirely different groups will be entirely separate. There is, for example, more genetic diversity in Africa (among the "black" race) than there is in the entire rest of the world combined -- the Navajo, Norwegians, and Japanese are
all more closely related to each other than, say, the Masai and Watusi.
Think of it this way : there are certainly biological species -- a "cat" is meaningful, as is a "dog." Those are biological constructs, not social ones. But suppose I wanted to define the super-categories of "pets" "food animals" and "predators." We would find that both cats and goldfish are "pets" and that sharks and wolves are predators. (And, of course tuna and cows are "food animals.") What biological basis can you make for that distinction?
Similarly, "cats" are pets, as are "dogs" -- but "wolves" and "tigers" are "predators." Chickens are "food animals" while eagles are "predators" and parakeets are "pets." Again, I defy you to justify this categorization biologically. The fact that some species are often kepts as pets and others are not does not in any way justify "pet" as a biological category; "pet" is a purely social construction.
So you're right about a Masai not being a pygmy. But what you can't do is defined what Masai and pygmies (and the rest of the "black" race) have in common that makes them "the same race," while excluding the Italians....