Evidence that two main bottleneck events shaped modern human genetic diversity — Proceedings B
There is a strong consensus that modern humans originated in Africa and moved out to colonize the world approximately 50 000 years ago. During the process of expansion, variability was lost, creating a linear gradient of decreasing diversity with [...]
In today’s Science, Jacobs et al discuss Ages for the Middle Stone Age of Southern Africa: Implications for Human Behavior and Dispersal:
The expansion of modern human populations in Africa 80,000 to 60,000 years ago and their initial exodus out of Africa have been tentatively linked to two phases of technological and behavioral [...]
Henn et al. in P.N.A.S. present Y-chromosomal evidence of a pastoralist migration through Tanzania to southern Africa (doi):
Although geneticists have extensively debated the mode by which agriculture diffused from the Near East to Europe, they have not directly examined similar agropastoral diffusions in Africa. It is unclear, for example, whether early [...]
Scientific American covers the human diaspora in a nice broad-brush overview:
Fifty or sixty thousand years ago a small band of Africans—a few hundred or even several thousand—crossed the strait in tiny boats, never to return.
The reason they left their homeland in eastern Africa is not completely understood. Perhaps the climate changed, or once [...]
John Hawks has a nicely detailed discussion about handling exponential growth in demographic models. Very interesting, and hopefully he’ll keep them coming:
Exponential growth is a feature of current human populations, and was may represent how the human population behaved during some episodes of its demographic history. However, “exponential” can mean different things to different [...]
Out in the AJHG, is the next in the National Genographic line of studies. This one, by Behar et al. assesses 624 mitochondrial genomes from Khoisan hunter gatherers in Africa (doi). The abstract says:
The quest to explain demographic history during the early part of human evolution has been limited because of [...]
No doubt you’ve all seen some of the hype surrounding the new book, Big Brain: The Origins and Future of Human Intelligence by Gary Lynch and Richard Granger. The book argues that a long-extinct hominin species, the “Boskops”, were much smarter then we are:
Our big brains, our language ability, and our intelligence make [...]
Through the magic of the internet (via), I’ve come across this posting where “DarkSoul” posts some photos of a modern day skirmish between the Kalenjin and Kisii tribes in Kenya. There’s an associated news story here, but I think the pictures can speak for themselves:
No time to read this now, but it looks very interesting: Proportionally more deleterious genetic variation in European than in African populations (doi). Abstract says -
Quantifying the number of deleterious mutations per diploid human genome is of crucial concern to both evolutionary and medical geneticists. Here we combine genome-wide polymorphism data from [...]
Out in PNAS – Maternal traces of deep common ancestry and asymmetric gene flow between Pygmy hunter–gatherers and Bantu-speaking farmers (doi:10.1073/pnas.0711467105):
Two groups of populations with completely different lifestyles—the Pygmy hunter–gatherers and the Bantu-speaking farmers—coexist in Central Africa. We investigated the origins of these two groups and the interactions between them, by analyzing [...]
