>one might predict a change in the dairy culture in Japan if suddenly the population was significantly more tolerant of lactose.
It might change or it might not. Just because a dietary option is open to you doesn't mean you're going to take it. Nothing prevents me from eating sushi, and I still don't, and the reason is obvious: I didn't grow up eating it, so it isn't part of my normal diet.
It's one thing to say that culture and genetics are not completely independent. It's another to say that culture is heavily influenced by genetics, to the extent that it's a hereditary trait.
It might change or it might not. Just because a dietary option is open to you doesn't mean you're going to take it. Nothing prevents me from eating sushi, and I still don't, and the reason is obvious: I didn't grow up eating it, so it isn't part of my normal diet.
It's one thing to say that culture and genetics are not completely independent. It's another to say that culture is heavily influenced by genetics, to the extent that it's a hereditary trait.