Barbujani G, Sokal R R, Oden N L
Dipartimento di Scienze Statistiche, Università di Bologna, Italy.
Am J Phys Anthropol. 1995 Feb;96(2):109-32. doi: 10.1002/ajpa.1330960202.
Allele frequency distributions were generated by computer simulation of five models of microevolution in European populations. Genetic distances calculated from these distributions were compared with observed genetic distances among Indo-European speakers. The simulated models differ in complexity, but all incorporate random genetic drift and short-range gene flow (isolation by distance). The best correlations between observed and simulated data were obtained for two models where dispersal of Neolithic farmers from the Near East depends only on population growth. More complex models, where the timing of the farmers' expansion is constrained by archaeological time data, fail to account for a larger fraction of the observed genetic variation; this is also the case for a model including late Neolithic migrations from the Pontic steppes. The genetic structure of current populations speaking Indo-European languages seems therefore to largely reflect a Neolithic expansion. This is consistent with the hypothesis of a parallel spread of farming technologies and a proto-Indo-European language in the Neolithic. Allele-frequency gradients among Indo-European speakers may be due either to incomplete admixture between dispersing farmers, who presumably spoke proto-Indo-European, and pre-existing hunters and gatherers (as in the traditional demic diffusion hypothesis), or to founder effects during the farmers' dispersal. By contrast, successive migrational waves from the East, if any, do not seem to have had genetic consequences detectable by the present comparison of observed and simulated allele frequencies.
等位基因频率分布是通过对欧洲人群中五种微进化模型进行计算机模拟生成的。根据这些分布计算出的遗传距离与印欧语系使用者之间观察到的遗传距离进行了比较。模拟模型在复杂性上有所不同，但都包含随机遗传漂变和短程基因流（距离隔离）。对于新石器时代农民从近东扩散仅取决于人口增长的两个模型，观察到的数据与模拟数据之间的相关性最佳。更复杂的模型，即农民扩张的时间受到考古时间数据的限制，无法解释更大比例的观察到的遗传变异；包括新石器时代晚期从 Pontic 草原迁徙的模型也是如此。因此，目前说印欧语系语言的人群的遗传结构似乎在很大程度上反映了新石器时代的扩张。这与新石器时代农业技术和原始印欧语系语言平行传播的假设一致。印欧语系使用者之间的等位基因频率梯度可能是由于推测说原始印欧语系的扩散农民与先前存在的猎人和采集者之间的不完全混合（如传统的人口扩散假说），或者是由于农民扩散期间的奠基者效应。相比之下，来自东方的连续迁徙浪潮（如果有的话）似乎并没有产生通过目前观察到的和模拟的等位基因频率比较可检测到的遗传后果。
