眼睛，毛发和皮肤色素在人种中是高度变化的， 特别是在西欧亚人种群体中。这种多样性可以解释为受到了人口历史，选择压力的缓和或显性选择等的影响。 为了调查显性自然选择是否会造成欧洲人种的色素脱失， 我们估计了选择作用对三种已知会对人体色素沉着产生显著作用的基因所产生的影响。 我们利用源自史前欧洲人的古代DNA和计算机模拟的直接方法作出了这些估计。这使我们能够将选择系数确定在较精确的远古年代范围内。我们的研究结果表明这种强劲选择在过去5千年中一直活跃在西欧亚大陆人种的色素相关基因中。
Eye, hair, and skin pigmentation are highly variable in humans, particularly in western Eurasian populations. This diversity may be explained by population history, the relaxation of selection pressures, or positive selection. To investigate whether positive natural selection is responsible for depigmentation within Europe, we estimated the strength of selection acting on three genes known to have significant effects on human pigmentation. In a direct approach, these estimates were made using ancient DNA from prehistoric Europeans and computer simulations. This allowed us to determine selection coefficients for a precisely bounded period in the deep past. Our results indicate that strong selection has been operating on pigmentation-related genes within western Eurasia for the past 5,000 y.
Pigmentation is a polygenic trait encompassing some of the most visible phenotypic variation observed in humans. Here we present direct estimates of selection acting on functional alleles in three key genes known to be involved in human pigmentation pathways—HERC2, SLC45A2, and TYR—using allele frequency estimates from Eneolithic, Bronze Age, and modern Eastern European samples and forward simulations. Neutrality was overwhelmingly rejected for all alleles studied, with point estimates of selection ranging from around 2–10% per generation. Our results provide direct evidence that strong selection favoring lighter skin, hair, and eye pigmentation has been operating in European populations over the last 5,000 y.