Beringia and the peopling of the Western Hemisphere

Abstract

Did Beringian environments represent an ecological barrier to humans until less than 15 000 years ago or was access to the Americas controlled by the spatial–temporal distribution of North American ice sheets? Beringian environments varied with respect to climate and biota, especially in the two major areas of exposed continental shelf. The East Siberian Arctic Shelf (‘Great Arctic Plain’ (GAP)) supported a dry steppe-tundra biome inhabited by a diverse large-mammal community, while the southern Bering-Chukchi Platform (‘Bering Land Bridge’ (BLB)) supported mesic tundra and probably a lower large-mammal biomass. A human population with west Eurasian roots occupied the GAP before the Last Glacial Maximum (LGM) and may have accessed mid-latitude North America via an interior ice-free corridor. Re-opening of the corridor less than 14 000 years ago indicates that the primary ancestors of living First Peoples, who already had spread widely in the Americas at this time, probably dispersed from the NW Pacific coast. A genetic ‘arctic signal’ in non-arctic First Peoples suggests that their parent population inhabited the GAP during the LGM, before their split from the former. We infer a shift from GAP terrestrial to a subarctic maritime economy on the southern BLB coast before dispersal in the Americas from the NW Pacific coast.

Uniparental genetic markers in Native Americans: A summary of all available data from ancient and contemporary populations

“…The peopling of the Americas by modern humans is a complex and fascinating chapter in human evolutionary history. Native Americans originated from a Beringian ancestral population that expanded into the American continent around 16,000 years before the present (ybp), according to genetic data, with multiple events of genetic contact among different ancient groups occurring thereafter (reviewed in Bisso‐Machado et al, 2016; Hoffecker et al, 2016; Mulligan & Szathmáry, 2017; Bisso‐Machado & Fagundes, 2019; Hoffecker et al, 2019; Pinotti et al, 2019). Starting from the early 1990's, uniparental genetic markers became the major genetic resource for studying evolutionary relationships among Native American populations.…”

High dispersal ability versus migratory traditions: Fine‐scale population structure and post‐glacial colonisation in bar‐tailed godwits

“…Presumably, subsequent re‐flooding of the Bering Strait (by c. 11K ybp) and incremental reduction and isolation of tundra habitat associated with the warming period leading to the mid‐Holocene Climatic Optimum (c. 8K ybp; Kraaijeveld & Nieboer, 2000; Stewart & Dalén, 2008; Wauchope et al., 2017) served to isolate these three extant lineages into their present‐day breeding ranges (Figure 1). Similar structure across Beringia is found in numerous avian species (Winker et al., 2023), and the deeper biogeographical history of the region, which includes the periodic appearance and disappearance of the Bering Land Bridge, is reflected in the complex histories of diverse taxa, including plants and humans (Hoffecker et al., 2023; Wen et al., 2016).…”