I should add that the differences between G-N are no greater than the differences between an Inuit and an African, or a pygmy and a European.
Bull-pucky. Absolute, undiluted, freshly-wet, fly-swarmed, horse manure.
I don't know if I can find your exact examples. But let's look at various human crania, including at least some native Africans and Amerindians. BTW, many of these are 19th drawings from a time when racial differences were typically (if anything) over emaphasized:
Bushman (African) and Fuegian (Pacific Islander)
Ah, darn. That's all I can google for now. Maybe more later. Anyway, this is baloney, but Merry Christmas.