title: Postglacial viability and colonization in North America's ice-free corridor.
abstract: During the Last Glacial Maximum, continental ice sheets isolated Beringia (northeast Siberia and northwest North America) from unglaciated North America. By around 15 to 14 thousand calibrated radiocarbon years before present (cal. kyr bp), glacial retreat opened an approximately 1,500-km-long corridor between the ice sheets. It remains unclear when plants and animals colonized this corridor and it became biologically viable for human migration. We obtained radiocarbon dates, pollen, macrofossils and metagenomic DNA from lake sediment cores in a bottleneck portion of the corridor. We find evidence of steppe vegetation, bison and mammoth by approximately 12.6 cal. kyr bp, followed by open forest, with evidence of moose and elk at about 11.5 cal. kyr bp, and boreal forest approximately 10 cal. kyr bp. Our findings reveal that the first Americans, whether Clovis or earlier groups in unglaciated North America before 12.6 cal. kyr bp, are unlikely to have travelled by this route into the Americas. However, later groups may have used this north-south passageway.
authors: Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Copenhagen 1350, Denmark.
authors: Mikkel W
authors: MW
authors: Pedersen
authors: Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Copenhagen 1350, Denmark.
authors: Anthony
authors: A
authors: Ruter
authors: Department of Anthropology, University of Alberta, Edmonton, Alberta T6G 2H4, Canada.
authors: Charles
authors: C
authors: Schweger
authors: Department of Anthropology, University of Alberta, Edmonton, Alberta T6G 2H4, Canada.
authors: Harvey
authors: H
authors: Friebe
authors: School of Archaeology, University of Oxford, Oxford OX1 3QY, UK.
authors: Richard A
authors: RA
authors: Staff
authors: Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Copenhagen 1350, Denmark.|Department of Earth Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
authors: Kristian K
authors: KK
authors: Kjeldsen
authors: Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Copenhagen 1350, Denmark.
authors: Marie L Z
authors: ML
authors: Mendoza
authors: Royal Alberta Museum, Edmonton, Alberta T5N 0M6, Canada.
authors: Alwynne B
authors: AB
authors: Beaudoin
authors: Department of Anthropology, MacEwan University, Edmonton, Alberta T5J 4S2, Canada.
authors: Cynthia
authors: C
authors: Zutter
authors: Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Copenhagen 1350, Denmark.|Department of Geoscience, Aarhus University, 8000 Aarhus, Denmark.
authors: Nicolaj K
authors: NK
authors: Larsen
authors: Department of Anthropology, University of Alaska Fairbanks, Fairbanks, Alaska 99775, USA.
authors: Ben A
authors: BA
authors: Potter
authors: Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Copenhagen 1350, Denmark.|Department of Integrative Biology, University of California, Berkeley, California 94720-3140, USA.|Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark.
authors: Rasmus
authors: R
authors: Nielsen
authors: Department of Archaeology, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
authors: Rebecca A
authors: RA
authors: Rainville
authors: Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Copenhagen 1350, Denmark.
authors: Ludovic
authors: L
authors: Orlando
authors: Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Copenhagen 1350, Denmark.|Department of Anthropology, Southern Methodist University, Dallas, Texas 75275, USA.
authors: David J
authors: DJ
authors: Meltzer
authors: Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Copenhagen 1350, Denmark.
authors: Kurt H
authors: KH
authors: Kjær
authors: Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Copenhagen 1350, Denmark.|Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.|Wellcome Trust Sanger Institute, Cambridge CB10 1SA, UK.
authors: Eske
authors: E
authors: Willerslev
mesh_terms: D025041:Animal Migration; D000818:Animals; D016164:Bison / Q000502:physiology; D004247:DNA / Q000032:analysis; D003670:Deer / Q000502:physiology; D065928:Forests; D005580:Fossils; D023281:Genomics; D019015:Geologic Sediments / Q000737:chemistry; D049690:History, Ancient; D063426:Human Migration / Q000266:history*; D006801:Humans; D046448:Ice Cover; D056665:Mammoths / Q000502:physiology; D008962:Models, Theoretical; D009656:North America; D011058:Pollen; D055110:Radiometric Dating; D012800:Siberia
chemical_list: D004247:DNA