Department of Human Genetics, The University of Chicago, Room 507, 929 E. 58th St, Chicago, IL 60637, USA.
Curr Biol. 2010 Feb 23;20(4):R208-15. doi: 10.1016/j.cub.2009.11.055.
There has long been interest in understanding the genetic basis of human adaptation. To what extent are phenotypic differences among human populations driven by natural selection? With the recent arrival of large genome-wide data sets on human variation, there is now unprecedented opportunity for progress on this type of question. Several lines of evidence argue for an important role of positive selection in shaping human variation and differences among populations. These include studies of comparative morphology and physiology, as well as population genetic studies of candidate loci and genome-wide data. However, the data also suggest that it is unusual for strong selection to drive new mutations rapidly to fixation in particular populations (the 'hard sweep' model). We argue, instead, for alternatives to the hard sweep model: in particular, polygenic adaptation could allow rapid adaptation while not producing classical signatures of selective sweeps. We close by discussing some of the likely opportunities for progress in the field.
长期以来，人们一直对理解人类适应的遗传基础感兴趣。在多大程度上，人类群体之间的表型差异是由自然选择驱动的？随着最近人类变异的大型全基因组数据集的出现，人们现在有了前所未有的机会来解决这类问题。有几条证据表明，正选择在塑造人类变异和人口之间的差异方面起着重要作用。这些证据包括对比较形态学和生理学的研究，以及对候选基因座和全基因组数据的群体遗传学研究。然而，这些数据也表明，在特定人群中，强烈的选择迅速将新突变驱动到固定状态（“硬扫除”模型）是不常见的。相反，我们提出了替代“硬扫除”模型的方法：特别是，多基因适应可以在不产生选择性扫除的经典特征的情况下允许快速适应。最后，我们讨论了该领域可能取得进展的一些机会。
