Le Megan K, Smith Olivia S, Akbari Ali, Harpak Arbel, Reich David, Narasimhan Vagheesh M
Department of Computer Science, The University of Texas at Austin.
Department of Integrative Biology, The University of Texas at Austin.
bioRxiv. 2022 Aug 26:2022.08.24.505188. doi: 10.1101/2022.08.24.505188.
Ancient DNA has revolutionized our understanding of human population history. However, its potential to examine how rapid cultural evolution to new lifestyles may have driven biological adaptation has not been met, largely due to limited sample sizes. We assembled genome-wide data from 1,291 individuals from Europe over 10,000 years, providing a dataset that is large enough to resolve the timing of selection into the Neolithic, Bronze Age, and Historical periods. We identified 25 genetic loci with rapid changes in frequency during these periods, a majority of which were previously undetected. Signals specific to the Neolithic transition are associated with body weight, diet, and lipid metabolism-related phenotypes. They also include immune phenotypes, most notably a locus that confers immunity to infection at a time when ancient genomes have been shown to adapt to human hosts, thus providing a possible example of human-pathogen co-evolution. In the Bronze Age, selection signals are enriched near genes involved in pigmentation and immune-related traits, including at a key human protein interactor of SARS-CoV-2. Only in the Historical period do the selection candidates we detect largely mirror previously-reported signals, highlighting how the statistical power of previous studies was limited to the last few millennia. The Historical period also has multiple signals associated with vitamin D binding, providing evidence that lactase persistence may have been part of an oligogenic adaptation for efficient calcium uptake and challenging the theory that its adaptive value lies only in facilitating caloric supplementation during times of scarcity. Finally, we detect selection on complex traits in all three periods, including selection favoring variants that reduce body weight in the Neolithic. In the Historical period, we detect selection favoring variants that increase risk for cardiovascular disease plausibly reflecting selection for a more active inflammatory response that would have been adaptive in the face of increased infectious disease exposure. Our results provide an evolutionary rationale for the high prevalence of these deadly diseases in modern societies today and highlight the unique power of ancient DNA in elucidating biological change that accompanied the profound cultural transformations of recent human history.
古代DNA彻底改变了我们对人类种群历史的理解。然而,由于样本量有限,其在研究快速的文化进化到新的生活方式如何驱动生物适应方面的潜力尚未得到充分发挥。我们收集了一万多年来来自欧洲的1291个人的全基因组数据,提供了一个足够大的数据集,以确定新石器时代、青铜时代和历史时期的选择时间。我们确定了25个在这些时期频率快速变化的基因位点,其中大多数以前未被发现。新石器时代过渡特有的信号与体重、饮食和脂质代谢相关的表型有关。它们还包括免疫表型,最显著的是一个在古代基因组已显示适应人类宿主时赋予抗感染能力的位点,从而提供了一个人类与病原体共同进化的可能例子。在青铜时代,选择信号在参与色素沉着和免疫相关性状的基因附近富集,包括在严重急性呼吸综合征冠状病毒2的一个关键人类蛋白相互作用因子处。只有在历史时期,我们检测到的选择候选基因在很大程度上反映了先前报道的信号,突出了先前研究的统计能力在过去几千年中是如何受到限制的。历史时期也有多个与维生素D结合相关的信号,这表明乳糖酶持久性可能是有效钙吸收的多基因适应的一部分,并对其适应性价值仅在于在稀缺时期促进热量补充的理论提出了挑战。最后,我们在所有三个时期都检测到了对复杂性状的选择,包括在新石器时代有利于降低体重的变异的选择。在历史时期,我们检测到有利于增加心血管疾病风险的变异的选择,这可能反映了对更活跃的炎症反应的选择,这种反应在面对增加的传染病暴露时可能是适应性的。我们的结果为当今现代社会中这些致命疾病的高发病率提供了一个进化的理论依据,并突出了古代DNA在阐明伴随近代人类历史深刻文化变革的生物变化方面的独特力量。