导读：家马很可能起源于欧亚大陆草原，也就是今天的乌克兰和哈萨克斯坦西部，并且随着牧群的扩展而不断与野马杂交繁殖。
马的驯化源于欧亚大陆西部
日前发表在《美国科学院院刊》上的一项研究提出，家马很可能起源于欧亚大陆草原，也就是今天的乌克兰和哈萨克斯坦西部，并且随着牧群的扩展而不断与野马杂交繁殖。
尽管经过了数十年的多样性研究，但是科研人员仍然对马的早期驯化历史有争议，并且对这段历史所知甚少。基于当前考古学、线粒体DNA以及Y—染色体排序等研究提供的证据，许多版本的马驯化过程被提出，例如，考古学证据提示马是在欧亚大陆西部草原驯化的，而来自现代母马的遗传证据指向了跨越广大的地理区域的多重驯化事件。
英国剑桥大学动物学系的Vera Warmuth及其同事使用来自欧亚大陆北部300多匹马的遗传数据，重建了现在家马已经灭绝的野生祖先野马（Equus ferus）的遗传结构，以及马的驯化在欧亚大陆草原的蔓延情况模型。Warmuth研究小组成员重建了野马的种群统计的历史，并且发现有力证据证明野马在大约1.6万年前就扩展出了欧亚大陆东部。“这很有可能反映了这些物种对于欧亚大陆的‘殖民’情况。”Warmuth表示。
通过进一步的分析，Warmuth研究小组认为，大约6000年前，马的驯化起源于欧亚大陆草原西部，并且被驯化的马群在欧亚大陆扩展的过程中不断有野马补充进来。研究人员表示，这些发现证实了马的驯化起源于欧亚大陆西部，并且有证据表明，家马的基因中不断有外来野马基因的注入，因此也就把此前考古学、线粒体DNA以及Y—染色体排序等研究提出的截然不同的证据结合起来，并解释了它们之中原有的冲突。
Reconstructing the origin and spread of horse domestication in the Eurasian steppe
Vera Warmutha,1,2, Anders Erikssona,1,2, Mim Ann Bowerb, Graeme Barkerb, Elizabeth Barrettb, Bryan Kent Hanksc, Shuicheng Lid, David Lomitashvilie, Maria Ochir-Goryaevaf, Grigory V. Sizonovg, Vasiliy Soyonovh, and Andrea Manicaa
Despite decades of research across multiple disciplines, the early history of horse domestication remains poorly understood. On the basis of current evidence from archaeology, mitochondrial DNA, and Y-chromosomal sequencing, a number of different domestication scenarios have been proposed, ranging from the spread of domestic horses out of a restricted primary area of domestication to the domestication of numerous distinct wild horse populations. In this paper, we reconstruct both the population genetic structure of the extinct wild progenitor of domestic horses, Equus ferus, and the origin and spread of horse domestication in the Eurasian steppes by fitting a spatially explicit stepping-stone model to genotype data from >300 horses sampled across northern Eurasia. We find strong evidence for an expansion of E. ferus out of eastern Eurasia about 160 kya, likely reflecting the colonization of Eurasia by this species. Our best-fitting scenario further suggests that horse domestication originated in the western part of the Eurasian steppe and that domestic herds were repeatedly restocked with local wild horses as they spread out of this area. By showing that horse domestication was initiated in the western Eurasian steppe and that the spread of domestic herds across Eurasia involved extensive introgression from the wild, the scenario of horse domestication proposed here unites evidence from archaeology, mitochondrial DNA, and Y-chromosomal DNA.
文献链接： https://www.pnas.org/content/early/2012/05/02/1111122109.abstract?sid=22978db8-aa2b-48b9-9cf3-d6a022b64270
