一项对坦桑尼亚和南非狩猎采集人群的50多万种遗传标记的研究显示，博茨瓦纳、纳米比亚和南非北部喀拉哈里沙漠地区的以咔哒声作为语言的布须曼人拥有全世界最高的遗传多样性水平。Brenna M. Henn及其同事研究了27个非洲人群的遗传标记，包括来自坦桑尼亚的哈扎人、散达维人的以咔哒声作为语言的个体和南非的Khomani布须曼人。这组作者探索了这些人群的祖先世系，来确定非洲的狩猎-采集人群和农业-游牧人群是否具有明显不同的人口历史。他们的分析提示这些狩猎-采集人群拥有其他非洲人口没有的遗传多样性。这组作者发现，在过去5000年中，随着农业人群在非洲扩展，像哈扎人这样的一些狩猎-采集者的人口规模急剧下降，而另外一些人群最近已经开始吸收农业移民。这组作者说，该研究发现的这种遗传多样性的模式提示，现代人起源于非洲南部，而不是此前认为的起源于东非。（生物谷Bioon.com）
生物谷推荐原文出处：
PNAS doi: 10.1073/pnas.1017511108
Hunter-gatherer genomic diversity suggests a southern African origin for modern humans
Brenna M. Henna,1, Christopher R. Gignouxb, Matthew Jobinc,d, Julie M. Grankae, J. M. Macphersonf, Jeffrey M. Kidda, Laura Rodríguez-Botiguég, Sohini Ramachandranh, Lawrence Honf, Abra Brisbini, Alice A. Linj, Peter A. Underhillj, David Comasg, Kenneth K. Kiddk, Paul J. Normanl, Peter Parhaml, Carlos D. Bustamantea, Joanna L. Mountainf, and Marcus W. Feldmane
Africa is inferred to be the continent of origin for all modern human populations, but the details of human prehistory and evolution in Africa remain largely obscure owing to the complex histories of hundreds of distinct populations. We present data for more than 580,000 SNPs for several hunter-gatherer populations: the Hadza and Sandawe of Tanzania, and the ≠Khomani Bushmen of South Africa, including speakers of the nearly extinct N|u language. We find that African hunter-gatherer populations today remain highly differentiated, encompassing major components of variation that are not found in other African populations. Hunter-gatherer populations also tend to have the lowest levels of genome-wide linkage disequilibrium among 27 African populations. We analyzed geographic patterns of linkage disequilibrium and population differentiation, as measured by FST, in Africa. The observed patterns are consistent with an origin of modern humans in southern Africa rather than eastern Africa, as is generally assumed. Additionally, genetic variation in African hunter-gatherer populations has been significantly affected by interaction with farmers and herders over the past 5,000 y, through both severe population bottlenecks and sex-biased migration. However, African hunter-gatherer populations continue to maintain the highest levels of genetic diversity in the world.
