I came across an interesting study by Penn State’s Stephan Schuster, to be published in Nature this month, finding that any two African bushmen who spoke different languages were more different genetically than a European and an Asian. That was true even if the bushmen lived within walking distance of each other.

This lends credence to the theory that non-Africans are descended from a single breeding female – our Mitochondrial Eve – who migrated from what is now Kenya to what is now Yemen ~150,000 years ago (and whose descendents apparently went on to populate all of non-Africa). Others may have crossed with her, and their maternal ancestry eliminated through some as of yet not understood mechanism. For example, the Toba supervolcanic eruption in Indonesia ~70,000 years ago caused an Ice Age that lasted for 1,800 years, reducing the non-African human population from about that of Boston to about that of Fenway Park. Mitochondrial Eve’s descendents, possibly further afield from Toba than others (the Levant, Europe, the Steppes, whatever), could have been the sole survivors. The rest of Africa, particularly the southern home of the bushmen, was free to intermingle and diversify their DNA-base.

The study also found 1.3 million tiny variations that hadn’t been observed before in any human DNA, suggesting that mitochondrial DNA may be more important to genetic diversification than previously thought, only 7,000 or so generations having passed since “Eve” migrated.

The engineering mastery and elegance of nature never ceases to amaze me.