Thing is race and sex are completely different. Race being a social construct is a lot more solid an argument than sex being a social construct.

See the thing with race is that is is a lot more like a "spectrum" though I hate that word for this. It's just that race isn't one thing or the other. It isn't bolian. Unless you go into stupid American race theory where it is all White or Not White or Black or not Black where convenient and lumping the vast majority of the world's population into the weird ass brown category, which they don't fit into cleanly anyway.

So like race, yeah personal appearance and shared genetic markers through relatives is a genetic thing that isn't "socially derived" and I guess if you want to boil race down entirely to appearance that's fine. But here is where I think it is completely different, how do you define the racial categories? Can you come up with some objective, non-culturally influenced criteria upon which you can classify the races and come to anything resembling what we know to be the racial categories as popularly believed? It's not as simple as ovum and sperm production.

Wanna do skin color? That's fine, what shade do you draw the line at? How about Mexicans and Arabs basically having the same skin color but not being the same race? Race or at the very least how we choose to categorize it is basically a kind of social construct and the races aren't exactly fixed either since, if you put two races together in the same island, lo and behold they will end up mixing and creating a new race out of the old races that don't really exist anymore.

So unlike sex, race sort of is fluid, sort of is a spectrum, and sort of is socially defined. It's just that the same idiocy that says you can get pregnant you just gotta believe is the same sort of idiocy that makes you think you can change your genetic heritage just by acting like a stereotype and making a funny face with plastic surgery.