Differences

I was wondering about differences in humans, this morning on my walk to work.

The differences between men and women (appart from the obvious, and partly because of the obvious) seem to be role-related. Men are physically bigger and stronger, which has always been attributed to men doing the hunting. Women became less capable of hunting because of changes in the female pelvis, due in turn to the increasing brain sizes at birth. I wonder whether this effect has partly affected the general differences in attitude. Men are generally less capable of multi-tasking and more attuned to plugging into a single task the to the exclusion of all else.

The I started thinking about regional differences. Recently a friend of mine pointed out the falsity in the assumption that black people have the pigmentation due to more sun. Is this were true then how come middle-eastern peoples (across the equator) are not darker than southern african peoples. Where did the facial features of eastern asian people come from? How come there are just a few physical shapes of caucasian people (the squat, dark haired and the tall, blonde shapes)?

Potentially there are actually more than one origins of the species? Perhaps it's not even that simple and I'm falling into the all-too-human trap of pattern-matching.