Durham Evolution and Ancient DNA, Department of Archaeology, University of Durham, Durham DH1 3LE, United Kingdom.
Proc Natl Acad Sci U S A. 2012 Jun 5;109(23):8878-83. doi: 10.1073/pnas.1203005109. Epub 2012 May 21.
The dog was the first domesticated animal but it remains uncertain when the domestication process began and whether it occurred just once or multiple times across the Northern Hemisphere. To ascertain the value of modern genetic data to elucidate the origins of dog domestication, we analyzed 49,024 autosomal SNPs in 1,375 dogs (representing 35 breeds) and 19 wolves. After combining our data with previously published data, we contrasted the genetic signatures of 121 breeds with a worldwide archeological assessment of the earliest dog remains. Correlating the earliest archeological dogs with the geographic locations of 14 so-called "ancient" breeds (defined by their genetic differentiation) resulted in a counterintuitive pattern. First, none of the ancient breeds derive from regions where the oldest archeological remains have been found. Second, three of the ancient breeds (Basenjis, Dingoes, and New Guinea Singing Dogs) come from regions outside the natural range of Canis lupus (the dog's wild ancestor) and where dogs were introduced more than 10,000 y after domestication. These results demonstrate that the unifying characteristic among all genetically distinct so-called ancient breeds is a lack of recent admixture with other breeds likely facilitated by geographic and cultural isolation. Furthermore, these genetically distinct ancient breeds only appear so because of their relative isolation, suggesting that studies of modern breeds have yet to shed light on dog origins. We conclude by assessing the limitations of past studies and how next-generation sequencing of modern and ancient individuals may unravel the history of dog domestication.
狗是第一种被驯化的动物，但驯化过程何时开始以及是否在北半球发生过一次或多次，仍然不确定。为了确定现代遗传数据在阐明犬类驯化起源方面的价值，我们分析了 1375 只狗（代表 35 个品种）和 19 只狼的 49024 个常染色体 SNP。在将我们的数据与之前发表的数据结合后，我们将 121 个品种的遗传特征与对最早的犬类遗骸的全球考古评估进行了对比。将最早的考古犬与 14 个所谓的“古老”品种（根据其遗传分化定义）的地理位置进行关联，结果产生了一种违反直觉的模式。首先，没有一个古老的品种来自最早的考古遗骸发现的地区。其次，三个古老的品种（贝生吉犬、澳洲野犬和新几内亚歌唱犬）来自于犬狼（犬类的野生祖先）自然分布范围之外的地区，而且这些犬类是在驯化后 10000 多年才被引入这些地区的。这些结果表明，所有具有遗传差异的所谓古老品种的统一特征是与其他品种的近期混合缺乏，这可能是由于地理和文化隔离所致。此外，这些具有遗传差异的古老品种之所以如此独特，仅仅是因为它们相对孤立，这表明对现代品种的研究尚未揭示犬类起源的奥秘。我们最后评估了过去研究的局限性，以及现代和古老个体的下一代测序如何可能揭示犬类驯化的历史。
