Recent acceleration of human adaptive evolution
Recent acceleration of human adaptive evolution
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DOI：
10.1073/pnas.0707650104
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发表时间：
2007-12-26
影响因子：
11.1
通讯作者：
Moyzis, Robert K.
中科院分区：
文献类型：
--
作者：
Hawks, John;Wang, Eric T.;Moyzis, Robert K.
对人类的基因组调查发现，最近有大量的积极选择。使用390万个HapMap SNP数据集，我们发现在过去的40,000年中，选择的速度大大加快。我们测试了零假设，即最近正向选择的连锁区块的观察到的年龄分布与人类进化过程中恒定的适应性替代速率一致。我们表明，一个足以解释最近选择的变体数量的恒定速率将预测(I)位置杂合度至少比在人类中观察到的低10倍，(它)杂合性和局部重组率的强烈关系，这在人类中没有观察到，(M)人类和黑猩猩之间令人难以置信的高数量的适应性替换，以及(Iv)观察到的高频连锁不平衡块数量的近100倍。更大的人口会产生更多的新的选择突变，我们证明了观察到的数据与人类人口增长的历史模式的一致性。我们认为，人口增长与过去人类文化和生态环境的变化有关。这两个过程都促成了我们物种最近异常快速的遗传进化。
Genomic surveys in humans identify a large amount of recent positive selection. Using the 3.9-million HapMap SNP dataset, we found that selection has accelerated greatly during the last 40,000 years. We tested the null hypothesis that the observed age distribution of recent positively selected linkage blocks is consistent with a constant rate of adaptive substitution during human evolution. We show that a constant rate high enough to explain the number of recently selected variants would predict (i) site heterozygosity at least 10-fold lower than is observed in humans, (it) a strong relationship of heterozygosity and local recombination rate, which is not observed in humans, (M) an implausibly high number of adaptive substitutions between humans and chimpanzees, and (iv) nearly 100 times the observed number of high-frequency linkage disequilibrium blocks. Larger populations generate more new selected mutations, and we show the consistency of the observed data with the historical pattern of human population growth. We consider human demographic growth to be linked with past changes in human cultures and ecologies. Both processes have contributed to the extraordinarily rapid recent genetic evolution of our species.