Belle Elise M S, Landry Pierre-Alexandre, Barbujani Guido
Università di Ferrara Dipartimento di Biologia Via Borsari 46, 44100 Ferrara, Italy.
Proc Biol Sci. 2006 Jul 7;273(1594):1595-602. doi: 10.1098/rspb.2006.3494.
There is general agreement that the current European gene pool is mainly derived from Palaeolithic hunting-gathering and Neolithic farming ancestors, but different studies disagree on the relative weight of these contributions. We estimated admixture rates in European populations from data on 377 autosomal microsatellite loci in 235 individuals, using five different numerical methods. On average, the Near Eastern (and presumably Neolithic) contribution was between 46 and 66%, and admixture estimates showed, with all methods, a strong and significant negative correlation with distance from the Near East. If the assumptions of the model are approximately correct, i.e. if the Basques' and Near Easterners' genomes represent a good approximation to the Palaeolithic and Neolithic settlers of Europe, respectively, these results imply that half or more of the Europeans' genes are descended from Near Eastern ancestors who immigrated in Europe 10000 years ago. If these assumptions are incorrect, our results show anyway that clinal variation is the rule in the Europeans' genomes and that lower estimates of Near Eastern admixture obtained from the analysis of single markers do not reflect the patterns observed at the genomic level.
目前人们普遍认为,当前的欧洲基因库主要源自旧石器时代的狩猎采集者和新石器时代的农耕祖先,但不同研究对于这些贡献的相对权重存在分歧。我们使用五种不同的数值方法,根据235名个体中377个常染色体微卫星位点的数据,估算了欧洲人群中的混合比例。平均而言,近东地区(大概是新石器时代)的贡献在46%至66%之间,并且所有方法得出的混合比例估算结果都显示,与距近东地区的距离呈强烈且显著的负相关。如果该模型的假设大致正确,即如果巴斯克人和近东人的基因组分别很好地代表了欧洲旧石器时代和新石器时代的定居者,那么这些结果意味着,欧洲人一半或更多的基因源自一万年前移民到欧洲的近东祖先。如果这些假设不正确,无论如何我们的结果都表明,渐变变异是欧洲人基因组的规律,并且通过单个标记分析得出的近东混合比例较低估计值并不能反映在基因组水平上观察到的模式。