I've recently joined Netflix and this is an FYI.
They have 2,800 documentaries and include many genres and makers (National Geo., BBC, PBS, Discovery, IMAX, etc.)
It's like having a classroom in your living room only better, imo! I watched The Real Eve tracing the mitichrondial DNA from one woman (not the Biblical Eve, but one in a group of people that were barely suriving).
It also answered the question of why black people are black and white people are white. Briefly, it's because living by the equator, especially in desert-like Africa at the time, the ultra-violet rays tended to destroy folate, which led to birth defects and deaths of fetuses. A lot of melanin in the skin protected them and they could then reproduce successfully. The darker the skin, the more you'd have offspring and pass on your genes.
As they migrated towards the poles and away from the equator, then the problem was production of vitamin D. There wasn't as much sunlight, so melanin prevented producing vitamin D, also essential for life. So the lighter people had more offspring, and so on till they became light-skinned. A geneticist said any group of black people would turn white and vice-versa within 20,000 years this way in those conditions.
Anyway, back to the selection of documentaries on Netflix---it's wonderful!
Pat