But the point is: Society unambiguously recognizes Obama as black. Biology does not. Therefore if you say society is wrong, you are just saying the social co

But the point is: Society unambiguously recognizes Obama as black. Biology does not. Therefore if you say society is wrong, you are just saying the social construct of race is wrong, and reinforcing the idea that race in our society is socially constructed and independent of any biological idea you can put forward. The larger question would be for shades that we might accept are "red" but don't necessarily meet the wavelength definition. Additionally human populations are not like wavelengths in that they are dynamically defined. You can find all sorts of populations with identifiable genetic similarities. However, we construct race differently than that. Arguing that society is biologically incorrect in a definition of race is just saying that the social construct is unmoored from the biology.