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The timing and effect of the earliest human arrivals in North America 期刊论文
NATURE, 2020
作者:  Lorena Becerra-Valdivia;  Thomas Higham
收藏  |  浏览/下载：27/0  |  提交时间：2020/08/09

The peopling of the Americas marks a major expansion of humans across the planet. However, questions regarding the timing and mechanisms of this dispersal remain, and the previously accepted model (termed '  Clovis-first'  )-suggesting that the first inhabitants of the Americas were linked with the Clovis tradition, a complex marked by distinctive fluted lithic points(1)-has been effectively refuted. Here we analyse chronometric data from 42 North American and Beringian archaeological sites using a Bayesian age modelling approach, and use the resulting chronological framework to elucidate spatiotemporal patterns of human dispersal. We then integrate these patterns with the available genetic and climatic evidence. The data obtained show that humans were probably present before, during and immediately after the Last Glacial Maximum (about 26.5-19 thousand years ago)(2,3)but that more widespread occupation began during a period of abrupt warming, Greenland Interstadial 1 (about 14.7-12.9 thousand years beforead 2000)(4). We also identify the near-synchronous commencement of Beringian, Clovis and Western Stemmed cultural traditions, and an overlap of each with the last dates for the appearance of 18 now-extinct faunal genera. Our analysis suggests that the widespread expansion of humans through North America was a key factor in the extinction of large terrestrial mammals.


A Bayesian age model suggests that human dispersal to the Americas probably began before the Last Glacial Maximum, overlapping with the last dates of appearance for several faunal genera.


  
Ice retreat in Wilkes Basin of East Antarctica during a warm interglacial 期刊论文
NATURE, 2020, 583 (7817) : 554-+
作者:  T. Blackburn;  G. H. Edwards;  S. Tulaczyk;  M. Scudder;  G. Piccione;  B. Hallet;  N. McLean;  J. C. Zachos;  B. Cheney;  J. T. Babbe
收藏  |  浏览/下载：21/0  |  提交时间：2020/08/09

Uranium isotopes in subglacial precipitates from the Wilkes Basin of the East Antarctic Ice Sheet reveal ice retreat during a warm Pleistocene interglacial period about 400,000 years ago.


Efforts to improve sea level forecasting on a warming planet have focused on determining the temperature, sea level and extent of polar ice sheets during Earth'  s past interglacial warm periods(1-3). About 400,000 years ago, during the interglacial period known as Marine Isotopic Stage 11 (MIS11), the global temperature was 1 to 2 degrees Celsius greater(2)and sea level was 6 to 13 metres higher(1,3). Sea level estimates in excess of about 10 metres, however, have been discounted because these require a contribution from the East Antarctic Ice Sheet(3), which has been argued to have remained stable for millions of years before and includes MIS11(4,5). Here we show how the evolution of(234)U enrichment within the subglacial waters of East Antarctica recorded the ice sheet'  s response to MIS11 warming. Within the Wilkes Basin, subglacial chemical precipitates of opal and calcite record accumulation of(234)U (the product of rock-water contact within an isolated subglacial reservoir) up to 20 times higher than that found in marine waters. The timescales of(234)U enrichment place the inception of this reservoir at MIS11. Informed by the(234)U cycling observed in the Laurentide Ice Sheet, where(234)U accumulated during periods of ice stability(6)and was flushed to global oceans in response to deglaciation(7), we interpret our East Antarctic dataset to represent ice loss within the Wilkes Basin at MIS11. The(234)U accumulation within the Wilkes Basin is also observed in the McMurdo Dry Valleys brines(8-10), indicating(11)that the brine originated beneath the adjacent East Antarctic Ice Sheet. The marine origin of brine salts(10)and bacteria(12)implies that MIS11 ice loss was coupled with marine flooding. Collectively, these data indicate that during one of the warmest Pleistocene interglacials, the ice sheet margin at the Wilkes Basin retreated to near the precipitate location, about 700 kilometres inland from the current position of the ice margin, which-assuming current ice volumes-would have contributed about 3 to 4 metres(13)to global sea levels.


  
Breaking Earth's shell into a global plate network 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Tang, C. A.;  Webb, A. A. G.;  Moore, W. B.;  Wang, Y. Y.;  Ma, T. H.;  Chen, T. T.
收藏  |  浏览/下载：10/0  |  提交时间：2020/07/21
Methylmercury produced in upper oceans accumulates in deep Mariana Trench fauna 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Sun, Ruoyu;  Yuan, Jingjing;  Sonke, Jeroen E.;  Zhang, Yanxu;  Zhang, Tong;  Zheng, Wang;  Chen, Shun;  Meng, Mei;  Chen, Jiubin;  Liu, Yi;  Peng, Xiaotong;  Liu, Congqiang
收藏  |  浏览/下载：10/0  |  提交时间：2020/07/09
Contactless probing of polycrystalline methane hydrate at pore scale suggests weaker tensile properties than thought 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Atig, Dyhia;  Broseta, Daniel;  Pereira, Jean-Michel;  Brown, Ross
收藏  |  浏览/下载：7/0  |  提交时间：2020/07/09
Increasing trends in regional heatwaves 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Perkins-Kirkpatrick, S. E.;  Lewis, S. C.
收藏  |  浏览/下载：2/0  |  提交时间：2020/07/06
Extreme climate after massive eruption of Alaska's Okmok volcano in 43 BCE and effects on the late Roman Republic and Ptolemaic Kingdom 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (27) : 15443-15449
作者:  McConnell, Joseph R.;  Sigl, Michael;  Plunkett, Gill;  Burke, Andrea;  Kim, Woon Mi;  Raible, Christoph C.;  Wilson, Andrew, I;  Manning, Joseph G.;  Ludlow, Francis;  Chellman, Nathan J.;  Innes, Helen M.;  Yang, Zhen;  Larsen, Jessica F.;  Schaefer, Janet R.;  Kipfstuhl, Sepp;  Mojtabavi, Seyedhamidreza;  Wilhelms, Frank;  Opel, Thomas;  Meyer, Hanno;  Steffensen, Jorgen Peder
收藏  |  浏览/下载：17/0  |  提交时间：2020/06/29
ice core  volcano  Okmok  Rome  climate forcing  
Extreme rainfall events alter the trophic structure in bromeliad tanks across the Neotropics 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Romero, Gustavo Q.;  39;Gorman, Eoin J.
收藏  |  浏览/下载：6/0  |  提交时间：2020/06/29
Contribution of land use to the interannual variability of the land carbon cycle 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Yue, Chao;  Ciais, Philippe;  Houghton, Richard A.;  Nassikas, Alexander A.
收藏  |  浏览/下载：11/0  |  提交时间：2020/06/29
Experimental evidence of dispersal of invasive cyprinid inside waterfowl 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (27) : 15397-15399
作者:  Lovas-Kiss, Adam;  Vincze, Orsolya;  Loki, Viktor;  Paller-Kapusi, Felicia;  Halasi-Kovacs, Bela;  Kovacs, Gyula;  Green, Andy J.;  Lukacs, Balazs Andras
收藏  |  浏览/下载：7/0  |  提交时间：2020/06/29
long-distance dispersal  freshwater  fish distribution  invasion  endozoochory