Menozzi P, Piazza A, Cavalli-Sforza L
Science. 1978 Sep 1;201(4358):786-92. doi: 10.1126/science.356262.
Multivarate techniques can be used to condense the information for a large number of loci and alleles into one or a few synthetic variables. The geographic distribution of synthetic variables can be plotted by the same technique used in mapping the gene frequency of a single allele. Synthetic maps were constructed for Europe and the Near East, with the use of principal components to condense the information of 38 independent alleles from ten loci. The first principal component summarizes close to 30% of the total information and shows gradients. Maps thus constructed show clines in remarkable agreement with those expected on the basis of the spread of early farming in Europe, thus supporting the hypothesis that this spread was a demic spread rather than a cultural diffusion of farming technology.
多变量技术可用于将大量基因座和等位基因的信息浓缩为一个或几个综合变量。综合变量的地理分布可以通过与绘制单个等位基因基因频率相同的技术来绘制。利用主成分分析来浓缩来自十个基因座的38个独立等位基因的信息，构建了欧洲和近东地区的综合地图。第一主成分总结了近30%的总信息并显示出梯度。这样构建的地图显示出的渐变与基于欧洲早期农业传播所预期的渐变显著一致，从而支持了这样一种假说，即这种传播是人口扩散而非农业技术的文化传播。
