Are there biological differences between people? Sure. But which differences are significant enough to draw a line and say, "On that side you are Race A, on this side you are Race B," tends to be answered by what axe one has to grind, who has the power, and who wants to be included with it. And the proof of that is where the "lines" have been drawn down through history.
Reshared post from +George Wiman
Define "race"? Easy! It's, um… Well you see, uh…
What We Mean When We Say ‘Race Is a Social Construct’
In a world where Kevin Garnett, Harold Ford, and Halle Berry all check “black” on the census, even the argument that racial labels refer to natural differences in physical traits doesn’t hold up.