The dawn of human matrilineal diversity
The dawn of human matrilineal diversity
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DOI：
10.1016/j.ajhg.2008.04.002
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发表时间：
2008-05-01
影响因子：
9.8
通讯作者：
Rosset, Saharon
中科院分区：
文献类型：
--
作者：
Behar, Doron M.;Villems, Richard;Rosset, Saharon
由于中石器时代的古人类学记录稀少，对人类进化早期人口历史的解释一直受限。为了阐明智人起源时线粒体DNA（mtDNA）系统发育的结构，我们构建了一棵母系树，它由来自撒哈拉以南非洲Hg L谱系的624个完整的mtDNA基因组组成。我们特别关注南非的科伊人和桑人（科伊桑人），因为他们被认为是狩猎采集生活方式的独特遗存，并且携带属于现代人类中已知最深分支的父系和母系谱系。系统发育树和溯祖计算都表明，科伊桑人的母系祖先在距今90,000 - 150,000年前从人类mtDNA库的其他部分分化出来，并且在此期间至少有另外五个目前仍然存在的母系谱系并行存在。此外，我们估计在大约60,000 - 70,000年前现代人类迁出非洲期间，撒哈拉以南非洲至少有40个其他在进化上成功的谱系繁荣发展。直到很久以后，在大约40,000年前的旧石器时代晚期开始时，才有其他谱系渗入科伊桑人的mtDNA库。在最近的班图人扩张期间，这一过程进一步加速。我们的研究结果表明，人类在非洲的早期定居已经具有母系结构，并且涉及小型的、独立进化的孤立种群。
The quest to explain demographic history during the early part of human evolution has been limited because of the scarce paleoanthropological record from the Middle Stone Age. To shed light on the structure of the mitochondrial DNA (mtDNA) phylogeny at the dawn of Homo sapiens, we constructed a matrilineal tree composed of 624 complete mtDNA genomes from sub-Saharan Hg L lineages. We paid particular attention to the Khoi and San (Khoisan) people of South Africa because they are considered to be a unique relic of hunter-gatherer lifestyle and to carry paternal and maternal lineages belonging to the deepest clades known among modern humans. Both the tree phylogeny and coalescence calculations suggest that Khoisan matrilineal ancestry diverged from the rest of the human mtDNA pool 90,000-150,000 years before present (ybp) and that at least five additional, currently extant maternal lineages existed during this period in parallel. Furthermore, we estimate that a minimum of 40 other evolutionarily successful lineages flourished in sub-Saharan Africa during the period of modern human dispersal out of Africa approximately 60,000-70,000 ybp. Only much later, at the beginning of the Late Stone Age, about 40,000 ybp, did introgression of additional lineages occur into the Khoisan mtDNA pool. This process was further accelerated during the recent Bantu expansions. Our results suggest that the early settlement of humans in Africa was already matrilineally structured and involved small, separately evolving isolated populations.