A hello from Britain page 2

[Lewis]

In terms of diets varying depending on where we come from, lactose tolerance amongst certain populations is an obvious one

So would celiac/coeliac be. And then there's sheer tolerance to carbohydrate. There seems to be a relation between this and light cycles - unsurprisingly I guess. (Electric light is going to disrupt that of course.) But Dr. Kruse, who has an interest in this, seems to think that one's immediate ancestry is of more relevance than what latitude one happens to be residing at now. There's a site in the U.S. where people check their genetic information with a view to bthis sort of thing. An interesting question would be how many people even know what's "in season" where they live.