During the last glacial-interglacial cycle, Arctic biotas experienced substantial climatic changes, yet the nature, extent and rate of their responses are not fully understood
. Here we report a ...large-scale environmental DNA metagenomic study of ancient plant and mammal communities, analysing 535 permafrost and lake sediment samples from across the Arctic spanning the past 50,000 years. Furthermore, we present 1,541 contemporary plant genome assemblies that were generated as reference sequences. Our study provides several insights into the long-term dynamics of the Arctic biota at the circumpolar and regional scales. Our key findings include: (1) a relatively homogeneous steppe-tundra flora dominated the Arctic during the Last Glacial Maximum, followed by regional divergence of vegetation during the Holocene epoch; (2) certain grazing animals consistently co-occurred in space and time; (3) humans appear to have been a minor factor in driving animal distributions; (4) higher effective precipitation, as well as an increase in the proportion of wetland plants, show negative effects on animal diversity; (5) the persistence of the steppe-tundra vegetation in northern Siberia enabled the late survival of several now-extinct megafauna species, including the woolly mammoth until 3.9 ± 0.2 thousand years ago (ka) and the woolly rhinoceros until 9.8 ± 0.2 ka; and (6) phylogenetic analysis of mammoth environmental DNA reveals a previously unsampled mitochondrial lineage. Our findings highlight the power of ancient environmental metagenomics analyses to advance understanding of population histories and long-term ecological dynamics.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
Early human dispersals within the Americas Moreno-Mayar, J Víctor; Vinner, Lasse; de Barros Damgaard, Peter ...
Science (American Association for the Advancement of Science),
12/2018, Volume:
362, Issue:
6419
Journal Article
Peer reviewed
Open access
Studies of the peopling of the Americas have focused on the timing and number of initial migrations. Less attention has been paid to the subsequent spread of people within the Americas. We sequenced ...15 ancient human genomes spanning from Alaska to Patagonia; six are ≥10,000 years old (up to ~18× coverage). All are most closely related to Native Americans, including those from an Ancient Beringian individual and two morphologically distinct "Paleoamericans." We found evidence of rapid dispersal and early diversification that included previously unknown groups as people moved south. This resulted in multiple independent, geographically uneven migrations, including one that provides clues of a Late Pleistocene Australasian genetic signal, as well as a later Mesoamerican-related expansion. These led to complex and dynamic population histories from North to South America.
For decades, archaeologists have debated whether Paleolithic humans withdrew from Northeast Asia during the Last Glacial Maximum (LGM), an issue especially important for the Pleistocene peopling of ...Siberia, Beringia, and the Americas. Evidence suggests a population contraction occurred around the global LGM between 26,000 and 20,000 cal BP. For one, gaps exist in prehistoric
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C records that separate older sites with no wedge-shaped microblade cores from younger sites with the technology. Also, variation between actual and simulated distributions of dates indicates periods of abandonment rather than continuous occupation. The maritime region of Sakhalin and Hokkaido, in contrast, may have experienced population expansion at the time when the islands were connected to mainland Asia as part of a peninsula. It is further possible that the genetic split between Paleo Siberians and ancestral Native Americans can be traced archaeologically through the distribution of wedge-shaped microblade cores from the coastal zones back into interior regions following the population contractions. Finally, if humans retreated from a greater part of Northeast Asia at the LGM, then a genetic standstill in Beringia or Siberia is difficult to reconcile.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
For a century, archaeologists have puzzled over the enigma of successful whaling unfolding with no predecessors prior to the last two millennia. The emergence of social complexity is linked with the ...appearance of the Old Bering Sea (OBS) aesthetic engraved on walrus ivory implements found in sites with large cemeteries and thick middens. Significantly, many OBS sites co-occur with major haulout locations for Pacific walrus, whose procurement engendered relationships that, along with seafaring or hunting technology, were the pivotal drivers that fostered whaling. Our revision of extant
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C assays to correct for marine carbon produces a younger 'Low' chronology placing the OBS florescence between AD 650-1250, with its earliest phase Okvik and allied Ipiutak communities from AD 300 to 600. The lithic technology of OBS is distinctive in its notched bifaces with affinities to 3000-year-old Chukchi Archaic assemblages. Later influences on OBS development include Ipiutak lithic technology and suggest migration, and either adversarial, or trading relationships with Alaska. The acquisition of rare commodities (driftwood, iron and obsidian) contributed to differential success and resulted in inequality recorded in burials.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Ground-penetrating radar (GPR) offers many advantages for assessing archaeological potential in frozen and partially frozen contexts in high latitude and alpine regions. These settings pose several ...challenges for GPR, including extreme velocity changes at the interface of frozen and active layers, cryogenic patterns resulting in anomalies that can easily be mistaken for cultural features, and the difficulty in accessing sites and deploying equipment in remote settings. In this study we discuss some of these challenges while highlighting the potential for this method by describing recent successful investigations with GPR in the region. We draw on cases from Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Kobuk Valley National Park, and Gates of the Arctic National Park and Preserve. The sites required small aircraft accessibility with light equipment loads and minimal personnel. The substrates we investigate include coastal saturated active layer over permafrost, interior well-drained active layer over permafrost, a frozen thermo-karst lake, and an alpine ice patch. These examples demonstrate that GPR is effective at mapping semi-subterranean house remains in several contexts, including houses with no surface manifestation. GPR is also shown to be effective at mapping anomalies from the skeletal remains of a late Pleistocene mammoth frozen in ice. The potential for using GPR in ice and snow patch archaeology, an area of increasing interest with global environmental change exposing new material each year, is also demonstrated.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Despite the ubiquity of obsidian in early Holocene archaeological assemblages across Southeast Alaska, artifact sourcing using bi‐plots and Principal Component Analysis has been hampered by the ...highly correlated geochemistry of two major sources: local Aguada Cove on Suemez Island, and distant Mount Edziza, in the Coast Mountain range. Partial Least Squares Discriminant Analysis (PLS‐DA) models constructed with device‐specific portable X‐ray fluorescence (pXRF) source catalogs benefit from the precision of individual pXRF machines and the ability of PLS‐DA to handle highly correlated data sets to provide a source classification system that complements existing methods. Of the known obsidian sources in or near Southeast Alaska, four are identified in early Holocene archaeological assemblages: Obsidian Cove and Aguada Cove on Suemez Island, Mount Edziza in the Coast Mountain Range, and a newly identified source on Zim Creek, Kupreanof Island. A comprehensive reanalysis of early Holocene microblade cores (101 cores from 13 archaeological sites) across Southeast Alaska confirms the presence of exotic obsidian from Mount Edziza in one of the oldest sites, alongside possible evidence of landscape learning: testing of the obsidian source on Kupreanof Island. The dominance of the Obsidian Cove source for microblade core production supports hypotheses framing Northwest Coast microblade core morphology as an adaptation to the small nodules of raw material available at the source. A simple distance‐decay model indicates no relationship between core reduction intensity and distance from the source, suggesting high forager mobility characterized by regular trips to Suemez Island (a voyage of up to 380 km) throughout the early Holocene.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Our understanding of the northern fluted point tradition, a critical early New World lithic assemblage, is constrained by limited data from stratified, datable contexts. Here, we report on the Raven ...Bluff site in northwest Alaska, where fluted projectile points, microblades, and a well‐preserved faunal assemblage have been recovered from datable sediments. Results show that prehistoric inhabitants occupied a stone‐sorted polygon where retooling, game processing, and raw material procurement occurred mostly between 12,720 and at least 11,340 cal. yr B.P. We argue that once polygon formation ended, the stratigraphic context remained relatively intact. Further studies focused on the site’s lithic and bone assemblages will help shape our understanding of the relationship between fluted point technology, microblades, and caribou hunting in northern Alaska.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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