An early dog from southeast Alaska supports a coastal route for the first dog migration into the Americas

Abstract

The oldest confirmed remains of domestic dogs in North America are from mid-continent archaeological sites dated approximately 9900 calibrated years before present (cal BP). Although this date suggests that dogs may not have arrived alongside the first Native Americans, the timing and routes for the entrance of New World dogs remain uncertain. Here, we present a complete mitochondrial genome of a dog from southeast Alaska, dated to 10 150 ± 260 cal BP. We compared this high-coverage genome with data from modern dog breeds, historical Arctic dogs and American precontact dogs (PCDs) from before European arrival. Our analyses demonstrate that the ancient dog belongs to the PCD lineage, which diverged from Siberian dogs around 16 700 years ago. This timing roughly coincides with the minimum suggested date for the opening of the North Pacific coastal (NPC) route along the Cordilleran Ice Sheet and genetic evidence for the initial peopling of the Americas. This ancient southeast Alaskan dog occupies an early branching position within the PCD clade, indicating it represents a close relative of the earliest PCDs that were brought alongside people migrating from eastern Beringia southward along the NPC to the rest of the Americas. The stable isotope δ 13 C value of this early dog indicates a marine diet, different from the younger mid-continent PCDs' terrestrial diet. Although PCDs were largely replaced by modern European dog breeds, our results indicate that their population decline started approximately 2000 years BP, coinciding with the expansion of Inuit peoples, who are associated with traditional sled-dog culture. Our findings suggest that dogs formed part of the initial human habitation of the New World, and provide insights into their replacement by both Arctic and European lineages.

Demography and evolutionary history of grey wolf populations around the Bering Strait

“…Archaeological and genetic evidence support the hypothesis that this coastal route was used by the first humans migrating into the Americas around 17 ka (Becerra‐Valdivia & Higham, 2020; Moreno‐Mayar et al, 2018; Pedersen et al, 2016). The same pattern is also being suggested for the early lineages of domesticated dogs, which diverged from the Eastern Siberian lineage c. 16 ka (da Silva Coelho et al, 2021). Other large carnivores, such as brown bears ( U. arctos ), could also have used this coastal route to reach the SEAk region c. 17 ka (Salis et al, 2021).…”

“…The same pattern is also being suggested for the early lineages of domesticated dogs, which diverged from the Eastern Siberian lineage c. 16 ka (da Silva Coelho et al, 2021). Other large carnivores, such as brown bears (U. arctos), could also have used this coastal route to reach the SEAk region c. 17 ka (Salis et al, 2021).…”

In situ evidence for Paleoindian hematite quarrying at the Powars II site (48PL330), Wyoming

“…Beyond its status as a hematite quarry, the Powars II artifact assemblage is itself one of densest and most diverse of any thus far discovered in the early Paleoindian record of the Americas. The site contains over 30 chipped stone tools per square meter, some of the oldest canid remains from an American archaeological site ( 22 ), and rare and/or unique faunal artifacts, among other distinctions. Despite the richness of our excavated sample, the site is known to contain artifacts that we did not recover within our 6-m 2 excavation, most notably Folsom and Agate Basin type spear points ( 1 ) and shell beads ( 2 ).…”

Virtual cultural landscapes: Geospatial visualizations of past environments

“…The current 'coastal migration hypothesis' suggests that people moved south of the continental glaciers by at least 14 050 cal BCE (16 000 cal BP), 1 based on Cooper's Ferry site (Figure 1a) (Davis et al, 2019), by travelling along the coast with the aid of watercraft. By colonizing unglaciated and deglaciated areas of the continental shelf of the Northwest Coast (NWC) of North America exposed by lower sea levels, these people followed what archaeologists refer to as the Pacific Coastal Route or kelp highway (Braje et al, 2017(Braje et al, , 2020da Silva Coelho et al, 2021;Davis & Madsen, 2020;Dixon, 2013aDixon, , 2013bFladmark, 1979;Gruhn, 1994;Heusser, 1955Heusser, , 1960Surovell, 2003). These early archaeological contexts provide evidence of human occupations along the Pacific Coastal Route and are discussed in detail elsewhere (see Braje et al, 2020).…”