Deep haplotype divergence and long-range linkage disequilibrium at Xp21.1 provide evidence that humans descend from a structured ancestral population
Deep haplotype divergence and long-range linkage disequilibrium at Xp21.1 provide evidence that humans descend from a structured ancestral population
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DOI：
10.1534/genetics.105.041095
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发表时间：
2005-08-01
期刊：
影响因子：
3.3
通讯作者：
Hammer, MF
中科院分区：
文献类型：
--
作者：
Garrigan, D;Mobasher, Z;Hammer, MF
化石证据将人类祖先与130，000 - 160，000年前从非洲现代纤细形态进化而来的人群联系起来。然而，化石本身并不能为所有现代智人的祖先是由一个单一的非洲种群组成，还是由不同的古代种群混合而成的问题提供明确的答案。DNA序列数据一直支持单一起源模型，即解剖学上的现代非洲人扩大并完全取代了所有其他古代人类种群。借助于一种新颖的实验设计，我们提出了第一个遗传证据，在统计上拒绝了零假设，即我们的物种来自一个单一的，历史上的panmictic人口。在全球42条X染色体的样本中，两个非洲个体携带一个非编码17.5 kb序列的谱系，该谱系已经存活了超过100万年，没有任何与该基因座上其他谱系进行重组的明确痕迹。这些模式的深单倍型分歧和长距离连锁不平衡是最好的解释了一个长期的祖先人口细分，其次是相对较近的杂交。这一推论支持了人类进化模型，该模型将人属不同非洲分支之间的混合物纳入其中。
Fossil evidence links human ancestry with populations that evolved from modern gracile morphology in Africa 130,000-160,000 years ago. Yet fossils alone do not provide clear answers to the question of whether the ancestors of all modern Homo sapiens comprised a single African population or an amalgamation of distinct archaic populations. DNA sequence data have consistently supported a single-origin model in which anatomically modern Africans expanded and completely replaced all other archaic hominin populations. Aided by a novel experimental design, we present the first genetic evidence that statistically rejects the null hypothesis that our species descends from a single, historically panmictic population. In a global sample of 42 X chromosomes, two African individuals carry a lineage of noncoding 17.5-kb sequence that has survived for > 1 million years without any clear traces of ongoing recombination with other lineages at this locus. These patterns of deep haplotype divergence and long-range linkage disequilibrium are best explained by a prolonged period of ancestral population subdivision followed by relatively recent interbreeding. This inference supports human evolution models that incorporate admixture between divergent African branches of the genus Homo.