Wooller Matthew J, Saulnier-Talbot Émilie, Potter Ben A, Belmecheri Soumaya, Bigelow Nancy, Choy Kyungcheol, Cwynar Les C, Davies Kimberley, Graham Russell W, Kurek Joshua, Langdon Peter, Medeiros Andrew, Rawcliffe Ruth, Wang Yue, Williams John W
Water and Environmental Research Center, Institute of Northern Engineering, Fairbanks, AK, USA.
Alaska Stable Isotope Facility, College of Fisheries and Ocean Sciences, Fairbanks, AK, USA.
R Soc Open Sci. 2018 Jun 20;5(6):180145. doi: 10.1098/rsos.180145. eCollection 2018 Jun.
Palaeoenvironmental records from the now-submerged Bering Land Bridge (BLB) covering the Last Glacial Maximum (LGM) to the present are needed to document changing environments and connections with the dispersal of humans into North America. Moreover, terrestrially based records of environmental changes are needed in close proximity to the re-establishment of circulation between Pacific and Atlantic Oceans following the end of the last glaciation to test palaeo-climate models for the high latitudes. We present the first terrestrial temperature and hydrologic reconstructions from the LGM to the present from the BLB's south-central margin. We find that the timing of the earliest unequivocal human dispersals into Alaska, based on archaeological evidence, corresponds with a shift to warmer/wetter conditions on the BLB between 14 700 and 13 500 years ago associated with the early Bølling/Allerød interstadial (BA). These environmental changes could have provided the impetus for eastward human dispersal at that time, from Western or central Beringia after a protracted human population standstill. Our data indicate substantial climate-induced environmental changes on the BLB since the LGM, which would potentially have had significant influences on megafaunal and human biogeography in the region.
需要来自现已淹没的白令陆桥（BLB）、涵盖末次盛冰期（LGM）至今的古环境记录，以记录环境变化以及与人类向北美扩散的联系。此外，在上次冰期末太平洋和大西洋之间的环流重新建立后，在其附近需要陆地环境变化记录，以检验高纬度地区的古气候模型。我们展示了来自BLB中南部边缘、从LGM至今的首批陆地温度和水文重建数据。我们发现，基于考古证据，人类最早明确向阿拉斯加扩散的时间，与14700至13500年前BLB上向更温暖/湿润条件的转变相对应，这与早期博林/阿勒罗德间冰期（BA）有关。这些环境变化可能为当时人类从白令陆桥西端或中部经过长期人口停滞后的向东扩散提供了动力。我们的数据表明，自LGM以来，BLB上发生了由气候引起的重大环境变化，这可能对该地区的大型动物群和人类生物地理学产生了重大影响。
