Genetic evidence of an early exit of Homo sapiens sapiens from Africa through eastern Africa
Genetic evidence of an early exit of Homo sapiens sapiens from Africa through eastern Africa
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DOI：
10.1038/70550
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发表时间：
1999-12-01
期刊：
影响因子：
30.8
通讯作者：
Santachiara-Benerecetti, AS
中科院分区：
文献类型：
--
作者：
Quintana-Murci, L;Semino, O;Santachiara-Benerecetti, AS
迄今为止，走出非洲的情景(1)还没有提供多少证据来证明现代人类离开非洲的确切路线。人们假设有两条主要的传播路线：一条通过北非进入黎凡特，有化石遗迹记录(2)，另一条沿南亚穿过埃塞俄比亚，但几乎没有证据存在(3)。线粒体 DNA (mtDNA) 可用于追踪母系血统，mtDNA 的地理分布和变异可以为确定遥远过去的潜在范围扩张和迁徙路线提供丰富的信息。线粒体单倍群 M 最初被认为是东亚起源的古老标记 (4,5)，但在印度 (6) 和埃塞俄比亚 (7) 频繁发现，引发了其起源问题。 （单倍群是一组共享某些序列变异的单倍型。）其变异和地理分布表明，亚洲单倍群 M 在 5 万多年前就与东非单倍群 M 分离。另外两个变体（489C 和 10873C）也支持单倍群 M 在非洲的单一起源。这些发现，再加上黎凡特单倍群 M 的实际缺失及其在南阿拉伯半岛的高频率，使 Rn 成为假设的从非洲经东非/印度西部出口路线的第一个遗传指标。这可能是现代人类唯一一次成功地走出非洲的早期扩散事件。
The out-of-Africa scenario(1) has hitherto provided little evidence for the precise route by which modern humans left Africa. Two major routes of dispersal have been hypothesized: one through North Africa into the Levant, documented by fossil remains(2), and one through Ethiopia along South Asia, for which little, if any, evidence exists(3). Mitochondrial DNA (mtDNA) can be used to trace maternal ancestry, The geographic distribution and variation of mtDNAs can be highly informative in defining potential range expansions and migration routes in the distant past. The mitochondrial haplogroup M, first regarded as an ancient marker of East-Asian origin(4,5), has been found at high frequency in India(6) and Ethiopia(7), raising the question of its origin. (A haplogroup is a group of haplotypes that share some sequence variations.) Its variation and geographical distribution suggest that Asian haplogroup M separated from eastern-African haplogroup M more than 50.000 years ago. Two other variants (489C and 10873C) also support a single origin of haplogroup M in Africa. These findings, together with the virtual absence of haplogroup M in the Levant and its high frequency in the South-Arabian peninsula, render Rn the first genetic indicator for the hypothesized exit route from Africa through eastern Africa/western India. This was possibly the only successful early dispersal event of modern humans out of Africa.