Canid Diversity and Conservation Unit, Veterinary Genetics Laboratory, University of California, Davis, USA.
Mol Biol Evol. 2013 May;30(5):1103-18. doi: 10.1093/molbev/mst027. Epub 2013 Feb 13.
Dogs originated more than 14,000 BP, but the location(s) where they first arose is uncertain. The earliest archeological evidence of ancient dogs was discovered in Europe and the Middle East, some 5-7 millennia before that from Southeast Asia. However, mitochondrial DNA analyses suggest that most modern dogs derive from Southeast Asia, which has fueled the controversial hypothesis that dog domestication originated in this region despite the lack of supporting archeological evidence. We propose and investigate with Y chromosomes an alternative hypothesis for the proximate origins of dogs from Southeast Asia--a massive Neolithic expansion of dogs from this region that largely replaced more primitive dogs to the west and north. Previous attempts to test matrilineal findings with independent patrilineal markers have lacked the necessary genealogical resolution and mutation rate estimates. Here, we used Y chromosome genotypes, composed of 29 single-nucleotide polymorphism (SNPs) and 5 single tandem repeats (STRs), from 338 Australian dingoes, New Guinea singing dogs, and village dogs from Island Southeast Asia, along with modern European breed dogs, to estimate the evolutionary mutation rates of Y chromosome STRs based on calibration to the independently known age of the dingo population. Dingoes exhibited a unique haplogroup characterized by a single distinguishing SNP mutation and 14 STR haplotypes. The age of the European haplogroup was estimated to be only 1.7 times older than that of the dingo population, suggesting an origin during the Neolithic rather than the Paleolithic (as predicted by the Southeast Asian origins hypothesis). We hypothesize that isolation of Neolithic dogs from wolves in Southeast Asia was a key step accelerating their phenotypic transformation, enhancing their value in trade and as cargo, and enabling them to rapidly expand and replace more primitive dogs to the West. Our findings also suggest that dingoes could have arrived in Australia directly from Taiwan, independently of later dispersals of dogs through Thailand to Island Southeast Asia.
狗起源于 14000 多年前,但它们最初出现的地点尚不确定。最早的古代犬类考古证据发现于欧洲和中东,比东南亚早了 5000-7000 年。然而,线粒体 DNA 分析表明,大多数现代犬类起源于东南亚,尽管缺乏支持这一假说的考古证据,但这一假说引发了争议,即犬类的驯化起源于该地区。我们提出并通过 Y 染色体来检验一个替代性假说,即来自东南亚的犬类的近源起源——来自该地区的大量新石器时代犬类扩张,这些犬类在很大程度上取代了西部和北部更为原始的犬类。此前,用独立的父系标记检验母系发现的尝试缺乏必要的谱系分辨率和突变率估计。在这里,我们使用了来自 338 只澳大利亚野狗、新几内亚歌唱犬和东南亚岛屿村落犬的 Y 染色体基因型,由 29 个单核苷酸多态性 (SNP) 和 5 个单串联重复 (STR) 组成,以及现代欧洲品种犬,根据对野狗种群年龄的独立校准,估计 Y 染色体 STR 的进化突变率。野狗表现出一个独特的单倍群,其特征是一个独特的 SNP 突变和 14 个 STR 单倍型。欧洲单倍群的年龄估计仅比野狗种群大 1.7 倍,这表明其起源于新石器时代,而不是旧石器时代(如东南亚起源假说所预测的那样)。我们假设,东南亚新石器时代犬类与狼的隔离是一个关键步骤,加速了它们的表型转变,提高了它们在贸易和货物运输中的价值,并使它们能够迅速扩张并取代西部更为原始的犬类。我们的研究结果还表明,野狗可能是直接从台湾到达澳大利亚的,与后来通过泰国向东南亚岛屿扩散的犬类无关。