论文标题
古老的人类Y染色体中的现代等位基因支持亚洲现代人类父亲谱系的起源
Modern alleles in archaic human Y chromosomes support origin of modern human paternal lineages in Asia rather than Africa
论文作者
论文摘要
最近的研究表明，现代和古人类之间的杂交在我们物种史上很普遍。混合后，一些具有混合常染色体的人携带现代的同性恋智人单元DNA，而其余的则携带了古代版本。预计混合常染色体和单元DNA的协同进化会导致现代单亲DNA中的某些地点恢复回古等位基因，而在古老的单亲DNA中，某些地点将发生相反的过程（从古老到现代）。这种类型的进化是区分现代人类的Y系统发育树的两个不同模型的元素之一，它植根于非洲或东亚。假定会发生预期向古等位基因的重新转换，并且在亚洲模型中很容易追溯，但是由于其无限位点的假设，在非洲模型中不存在，这也是由于假定突变的发生在古代独立DNA中的现代等位基因的独立或收敛的突变，因此假定突变是随机发生的，而不是在中性旋转组中随机发生，并且会发生融合的融合。在这里，我们检查了新发表的两个denisovan和两个尼安德特人样本的染色体测序数据，以确定它们是否在不应该根据非洲模型的地点携带现代的Homo Sapiens等位基因。结果表明，根据亚洲模型，很大一部分应该将原始现代Y与原始的古老Y区分开，并在此处携带的现代等位基因。这些现代等位基因中的一些是在所有古老的人类中共享的，而另一些现代等位基因则可以将丹尼索瓦人与尼安德特人区分开。该观察结果最好由古老的Y和混合现代常染色体的共同进化来解释，因此可以支持亚洲模型，因为它考虑了这种共同的进化。
Recent studies have shown that hybridization between modern and archaic humans was commonplace in the history of our species. After admixture, some individuals with admixed autosomes carried the modern Homo Sapiens uniparental DNAs, while the rest carried the archaic versions. Coevolution of admixed autosomes and uniparental DNAs is expected to cause some of the sites in modern uniparental DNAs to revert back to archaic alleles, while the opposite process would occur (from archaic to modern) in some of the sites in archaic uniparental DNAs. This type of coevolution is one of the elements that differentiate the two different models of the Y phylogenetic tree of modern humans, rooting it either in Africa or East Asia. The expected reversion to archaic alleles is assumed to occur and is easily traceable in the Asia model, but is absent in the Africa model due to its infinite site assumption, which also precludes the independent or convergent mutation to modern alleles in archaic uniparental DNAs since mutations are assumed to occur randomly across a neutral genome, and convergent evolution is assumed not to occur. Here, we examined newly published high coverage Y chromosome sequencing data of two Denisovan and two Neanderthal samples to determine whether they carry modern-Homo Sapiens alleles in sites where they are not supposed to according to the Africa model. The results showed that a significant fraction of the sites that, according to the Asia model, should differentiate the original modern Y from the original archaic Y carried modern alleles in the archaic Y samples here. Some of these modern alleles were shared among all archaic humans while others could differentiate Denisovans from Neanderthals. The observation is best accounted for by coevolution of archaic Y and admixed modern autosomes, and hence supports the Asia model, since it takes such coevolution into account.
