Transmissible Cancer Group, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK.
Department of Archaeology, Durham University, Durham, UK.
Science. 2018 Jul 6;361(6397):81-85. doi: 10.1126/science.aao4776.
Dogs were present in the Americas before the arrival of European colonists, but the origin and fate of these precontact dogs are largely unknown. We sequenced 71 mitochondrial and 7 nuclear genomes from ancient North American and Siberian dogs from time frames spanning ~9000 years. Our analysis indicates that American dogs were not derived from North American wolves. Instead, American dogs form a monophyletic lineage that likely originated in Siberia and dispersed into the Americas alongside people. After the arrival of Europeans, native American dogs almost completely disappeared, leaving a minimal genetic legacy in modern dog populations. The closest detectable extant lineage to precontact American dogs is the canine transmissible venereal tumor, a contagious cancer clone derived from an individual dog that lived up to 8000 years ago.
狗在欧洲殖民者到达美洲之前就已经存在于美洲，但这些史前狗的起源和命运在很大程度上是未知的。我们对来自北美和西伯利亚的 71 个线粒体和 7 个核基因组进行了测序，这些样本的时间跨度约为 9000 年。我们的分析表明，美洲的狗不是由北美狼衍生而来的。相反，美洲的狗形成了一个单系群，可能起源于西伯利亚，并与人类一起扩散到美洲。欧洲人到来后，美洲本土的狗几乎完全消失了，在现代犬种群中只留下了微不足道的遗传痕迹。与史前美洲狗最接近的现存可检测世系是犬传染性性病肿瘤，这是一种传染性癌症克隆，源自一只生活在 8000 年前的狗。
