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 Palaeo-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 Palaeo-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 Palaeo-Inuit dogs, and probably aided the Inuit expansion across the North American Arctic beginning around 1000 BP.

Deciphering diet and monitoring movement: Multiple stable isotope analysis of the viking age settlement at Hofstaðir, Lake Mývatn, Iceland.

OBJECTIVES: A previous multi-isotope study of archaeological faunal samples from Skútustaðir, an early Viking age settlement on the southern shores of Lake Mývatn in north-east Iceland, demonstrated that there are clear differences in δ(34)S stable isotope values between animals deriving their dietary protein from terrestrial, freshwater, and marine reservoirs. The aim of this study was to use this information to more accurately determine the diet of humans excavated from a nearby late Viking age churchyard. MATERIALS AND METHODS: δ(13)C, δ(15)N, and δ(34)S analyses were undertaken on terrestrial animal (n = 39) and human (n = 46) bone collagen from Hofstaðir, a high-status Viking-period farmstead ∼10 km north-west of Skútustaðir. RESULTS: δ(34)S values for Hofstaðir herbivores were ∼6‰ higher relative to those from Skútustaðir (δ(34)S: 11.4 ± 2.3‰ versus 5.6 ± 2.8‰), while human δ(13)C, δ(15)N, and δ(34)S values were broad ranging (-20.2‰ to -17.3‰, 7.4‰ to 12.3‰, and 5.5‰ to 14.9‰, respectively). DISCUSSION: Results suggest that the baseline δ(34)S value for the Mývatn region is higher than previously predicted due to a possible sea-spray effect, but the massive deposition of Tanytarsus gracilentus (midges) (δ(34)S: -3.9‰) in the soil in the immediate vicinity of the lake is potentially lowering this value. Several terrestrial herbivores displayed higher bone collagen δ(34)S values than their contemporaries, suggesting trade and/or movement of animals to the region from coastal areas. Broad ranging δ(13)C, δ(15)N, and δ(34)S values for humans suggest the population were consuming varied diets, while outliers within the dataset could conceivably have been migrants to the area.