Datasets S5 from Specialized sledge dogs accompanied Inuit dispersal across the North American Arctic

Domestic dogs have been central to life in the North American Arctic for millennia. The ancestors of the Inuit were the first to introduce the widespread usage of dog sledge transportation technology to the Americas, but whether the Inuit adopted local Paleo-Inuit dogs or introduced a new dog population to the region remains unknown. To test these hypotheses, we generated mitochondrial DNA and geometric morphometric data of skull and dental elements from a total of 922 North American Arctic dogs and wolves spanning over 4500 years. Our analyses revealed that dogs from Inuit sites dating from 2000 BP possess morphological and genetic signatures that distinguish them from earlier Paleo-Inuit dogs, and identified a novel mitochondrial clade in eastern Siberia and Alaska. The genetic legacy of these Inuit dogs survives today in modern Arctic sledge dogs despite phenotypic differences between archaeological and modern Arctic dogs. Together, our data reveal that Inuit dogs derive from a secondary pre-contact migration of dogs distinct from Paleo-Inuit dogs, and most likely aided the Inuit expansion across the North American Arctic beginning around 1000 BP.

家犬自千余年前便成为北美北极地区生活的重要构成。爱斯基摩人的先祖是首个将狗拉雪橇运输技术广泛应用于美洲的群体，然而，爱斯基摩人是否采纳了当地的帕莱奥-爱斯基摩犬，或是引入了新的犬种至该地区，至今仍是个谜。为了验证这些假设，我们收集了922只北美北极地区犬类和狼类的线粒体DNA以及颅骨和牙齿元素几何形态测量数据，时间跨度超过4500年。我们的分析揭示，公元前2000年左右的爱斯基摩犬在形态学和遗传特征上与早期帕莱奥-爱斯基摩犬有显著区别，并在西伯利亚东部和阿拉斯加地区识别出一个新的线粒体类群。这些爱斯基摩犬的遗传遗产至今仍存在于现代北极雪橇犬中，尽管考古学上的北极犬与现代北极犬在表型上存在差异。我们的数据共同表明，爱斯基摩犬源自一次独立于帕莱奥-爱斯基摩犬的次级接触前犬种迁移，且很可能自公元前1000年起助力了爱斯基摩人在北美北极地区的扩张。