The few really dark-skin tribes of South America were late arrivals because almost all of the ancient tribes there near the equator are clearly of much lighter skin than those of equatorial Africa and India, so how do the darwinists explain that?

Presumably dark skin would always come forth for people living in more direct sunlight near the equator, no matter the continent, so obviously people who had naturally selected for lighter skin then migrated to South America, and that was across the Atlantic from the empire of Atlantis.

So-called negroid features are seen characteristic of many of the great stone head statues of the Olmecs, some too with clearly orential features, in Mesoamerica, where the real action was during and after the Ice Age.