The evolution of dog diet and foraging: Insights from archaeological canids in Siberia.

Research on the evolution of dog foraging and diet has largely focused on scavenging during their initial domestication and genetic adaptations to starch-rich food environments following the advent of agriculture. The Siberian archaeological record evidences other critical shifts in dog foraging and diet that likely characterize Holocene dogs globally. By the Middle Holocene, body size reconstruction for Siberia dogs indicates that most were far smaller than Pleistocene wolves. This contributed to dogs' tendencies to scavenge, feed on small prey, and reduce social foraging. Stable carbon and nitrogen isotope analysis of Siberian dogs reveals that their diets were more diverse than those of Pleistocene wolves. This included habitual consumption of marine and freshwater foods by the Middle Holocene and reliance on C4 foods by the Late Holocene. Feeding on such foods and anthropogenic waste increased dogs' exposure to microbes, affected their gut microbiomes, and shaped long-term dog population history.

Human population dynamics and Yersinia pestis in ancient northeast Asia.

We present genome-wide data from 40 individuals dating to c.16,900 to 550 years ago in northeast Asia. We describe hitherto unknown gene flow and admixture events in the region, revealing a complex population history. While populations east of Lake Baikal remained relatively stable from the Mesolithic to the Bronze Age, those from Yakutia and west of Lake Baikal witnessed major population transformations, from the Late Upper Paleolithic to the Neolithic, and during the Bronze Age, respectively. We further locate the Asian ancestors of Paleo-Inuits, using direct genetic evidence. Last, we report the most northeastern ancient occurrence of the plague-related bacterium, Yersinia pestis Our findings indicate the highly connected and dynamic nature of northeast Asia populations throughout the Holocene.

Investigating Holocene human population history in North Asia using ancient mitogenomes.

Archaeogenomic studies have largely elucidated human population history in West Eurasia during the Stone Age. However, despite being a broad geographical region of significant cultural and linguistic diversity, little is known about the population history in North Asia. We present complete mitochondrial genome sequences together with stable isotope data for 41 serially sampled ancient individuals from North Asia, dated between c.13,790 BP and c.1,380 BP extending from the Palaeolithic to the Iron Age. Analyses of mitochondrial DNA sequences and haplogroup data of these individuals revealed the highest genetic affinity to present-day North Asian populations of the same geographical region suggesting a possible long-term maternal genetic continuity in the region. We observed a decrease in genetic diversity over time and a reduction of maternal effective population size (Ne) approximately seven thousand years before present. Coalescent simulations were consistent with genetic continuity between present day individuals and individuals dating to 7,000 BP, 4,800 BP or 3,000 BP. Meanwhile, genetic differences observed between 7,000 BP and 3,000 BP as well as between 4,800 BP and 3,000 BP were inconsistent with genetic drift alone, suggesting gene flow into the region from distant gene pools or structure within the population. These results indicate that despite some level of continuity between ancient groups and present-day populations, the region exhibits a complex demographic history during the Holocene.

A Second Mortuary Hiatus on Lake Baikal in Siberia and the Arrival of Small-Scale Pastoralism.

The spread of pastoralism in Asia is poorly understood, including how such processes affected northern forager populations. Lake Baikal's western shore has a rich Holocene archaeological record that tracks these processes. The Early Bronze Age here is evidenced by numerous forager burials. The Early Iron Age (EIA) is thought to mark the arrival of pastoralists, but archaeological remains from this period have received little analysis. New radiocarbon dates for EIA human remains from 23 cemeteries indicate that no burials were created along this shore for ~900 years. This period, from ~3670 to 2760 cal. BP, spans from the end of the Early Bronze Age to the advent of the EIA. The burial gap may mark disruption of local foraging populations through incursions by non-local pastoralists. Radiocarbon dates on faunal remains indicate that domestic herd animals first appear around 3275 cal. BP, just prior to the first EIA human burials. Stable carbon and nitrogen isotope analysis of human remains and zooarchaeological data indicate that domestic fauna were minor dietary components for EIA people. Like preceding foragers, the EIA groups relied extensively on Baikal's aquatic food sources, indicating that the scale of pastoralism during this period was relatively limited.