Cavalli-Sforza L
Department of Genetics, Stanford University, California, USA.
Pathol Biol (Paris). 1998 Feb;46(2):98-102.
Population genetics is almost eighty years old, but benefited only very recently from the advantages of direct DNA analysis. Nevertheless, much knowledge had already accumulated and was completely confirmed by the study of DNA markers. Major benefits of the latter came with microsatellites. It allowed to discover an error made with classical markers but even more seriously with RFLPs, because of the practically involuntary sampling of individuals almost exclusively of European origin for the detection of polymorphisms. Among other evolutionary application of microsatellites, the most attractive is their very recent use for dating population separations during the recent migration out of Africa of modern humans. They confirm the theory that this expansion was quite recent. Single nucleotide substitutions are the major material of evolution, and so far markers of this kind were rare. A new method, DHPLC, is excellent for their detection and testing. In humans it has been applied almost exclusively to the Y chromosome, and in a year it has given a completely new picture of Y chromosome genetics. Some applications of statistical methods to genetic geography of classical markers and ADN markers will show the power of the geographical approach, and therefore the need of a wide collection of population samples, as will be made possible by the HGDP (Human Genome Diversity Project).
群体遗传学已有近八十年的历史，但直到最近才受益于直接DNA分析的优势。尽管如此，此前已经积累了大量知识，并且通过对DNA标记的研究得到了充分证实。微卫星给后者带来了主要益处。它使得人们发现了经典标记存在的一个错误，而对于限制性片段长度多态性（RFLP）来说，这个错误更为严重，因为在检测多态性时，几乎完全是无意中选取了几乎清一色欧洲裔的个体进行抽样。在微卫星的其他进化应用中，最吸引人的是其最近用于确定现代人类近期从非洲迁出期间群体分离时间的用途。它们证实了这种扩张是相当近期发生的这一理论。单核苷酸替换是进化的主要物质，而到目前为止这类标记很少见。一种新方法，变性高效液相色谱法（DHPLC），非常适合对其进行检测和测试。在人类中，它几乎只应用于Y染色体，并且在一年内就给出了Y染色体遗传学的全新图景。将统计方法应用于经典标记和DNA标记的遗传地理学的一些实例将展示地理方法的强大作用，因此也凸显了广泛收集群体样本的必要性，而人类基因组多样性计划（HGDP）将使之成为可能。
