> So how exactly does the diet of Mongolians prove lactase persistence is not fundamentally genetic? It doesn't, but I think it indicates that genetic lactase

> So how exactly does the diet of Mongolians prove lactase persistence is not fundamentally genetic? It doesn't, but I think it indicates that genetic lactase persistence is not the only factor that affects lactose intolerance. Otherwise, how do you call a lactose-intolerant person that can tolerate significant amounts of lactose?