Since the Arctic is not Asia is not Africa, there is no surprise that there might be different selection pressures, and the real question is why one would expect selection pressures to be universally identical such that evolution would stop at the neck.
The real question is why you think selection pressures in Africa, which is an extraordinarily diverse continent, would be universally identical such that evolution would stop at the neck. You keep bringing up “disease burden”—okay, I’ll bite. What’s your evidence that disease burden was substantially different in Africa, as a whole, than anywhere else prior to industrialization?
What’s your evidence that disease burden was substantially different in Africa, as a whole, than anywhere else prior to industrialization?
This is not a controversial point. Warmer and tropical climates have always had higher parasite and disease loads than colder ones. If you disagree with basic stuff like this, the burden is on you.
Although in this case the relevant factor is that since humans originally evolved in Africa, it had more diseases that co-evolved with humans. Hence why South America, which has a cilmate similar to Africa had an even lower disease burden than Europe. At least until Europeans brought Africans, some of whom were infected with African diseases there.
The real question is why you think selection pressures in Africa, which is an extraordinarily diverse continent, would be universally identical such that evolution would stop at the neck. You keep bringing up “disease burden”—okay, I’ll bite. What’s your evidence that disease burden was substantially different in Africa, as a whole, than anywhere else prior to industrialization?
This is not a controversial point. Warmer and tropical climates have always had higher parasite and disease loads than colder ones. If you disagree with basic stuff like this, the burden is on you.
Although in this case the relevant factor is that since humans originally evolved in Africa, it had more diseases that co-evolved with humans. Hence why South America, which has a cilmate similar to Africa had an even lower disease burden than Europe. At least until Europeans brought Africans, some of whom were infected with African diseases there.
You might want to look at Africa on a map, because it isn’t all tropical.
You seem to be thinking of Africa as a tiny place with uniform geography and climate and biome—it’s not.