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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.


  
Patterns and trends of Northern Hemisphere snow mass from 1980 to 2018 期刊论文
NATURE, 2020, 581 (7808) : 294-+
作者:  Ibrahim, Nizar;  Maganuco, Simone;  Dal Sasso, Cristiano;  Fabbri, Matteo;  Auditore, Marco;  Bindellini, Gabriele;  Martill, David M.;  Zouhri, Samir;  Mattarelli, Diego A.;  Unwin, David M.;  Wiemann, Jasmina;  Bonadonna, Davide;  Amane, Ayoub;  Jakubczak, Juliana;  Joger, Ulrich;  Lauder, George V.;  Pierce, Stephanie E.
收藏  |  浏览/下载:18/0  |  提交时间:2020/05/25

Warming surface temperatures have driven a substantial reduction in the extent and duration of Northern Hemisphere snow cover(1-3). These changes in snow cover affect Earth'  s climate system via the surface energy budget, and influence freshwater resources across a large proportion of the Northern Hemisphere(4-6). In contrast to snow extent, reliable quantitative knowledge on seasonal snow mass and its trend is lacking(7-9). Here we use the new GlobSnow 3.0 dataset to show that the 1980-2018 annual maximum snow mass in the Northern Hemisphere was, on average, 3,062 +/- 35 billion tonnes (gigatonnes). Our quantification is for March (the month that most closely corresponds to peak snow mass), covers non-alpine regions above 40 degrees N and, crucially, includes a bias correction based on in-field snow observations. We compare our GlobSnow 3.0 estimates with three independent estimates of snow mass, each with and without the bias correction. Across the four datasets, the bias correction decreased the range from 2,433-3,380 gigatonnes (mean 2,867) to 2,846-3,062 gigatonnes (mean 2,938)-a reduction in uncertainty from 33% to 7.4%. On the basis of our bias-corrected GlobSnow 3.0 estimates, we find different continental trends over the 39-year satellite record. For example, snow mass decreased by 46 gigatonnes per decade across North America but had a negligible trend across Eurasia  both continents exhibit high regional variability. Our results enable a better estimation of the role of seasonal snow mass in Earth'  s energy, water and carbon budgets.


Applying a bias correction to a state-of-the-art dataset covering non-alpine regions of the Northern Hemisphere and to three other datasets yields a more constrained quantification of snow mass in March from 1980 to 2018.


  
Early Holocene crop cultivation and landscape modification in Amazonia 期刊论文
NATURE, 2020, 581 (7807) : 190-+
作者:  Hendershot, J. Nicholas;  Smith, Jeffrey R.;  Anderson, Christopher B.;  Letten, Andrew D.;  Frishkoff, Luke O.;  Zook, Jim R.;  Fukami, Tadashi;  Daily, Gretchen C.
收藏  |  浏览/下载:32/0  |  提交时间:2020/07/03

The onset of plant cultivation is one of the most important cultural transitions in human history(1-4). Southwestern Amazonia has previously been proposed as an early centre of plant domestication, on the basis of molecular markers that show genetic similarities between domesticated plants and wild relatives(4-6). However, the nature of the early human occupation of southwestern Amazonia, and the history of plant cultivation in this region, are poorly understood. Here we document the cultivation of squash (Cucurbita sp.) at about 10,250 calibrated years before present (cal. yr bp), manioc (Manihot sp.) at about 10,350 cal. yr bp and maize (Zea mays) at about 6,850 cal. yr bp, in the Llanos de Moxos (Bolivia). We show that, starting at around 10,850 cal. yr bp, inhabitants of this region began to create a landscape that ultimately comprised approximately 4,700 artificial forest islands within a treeless, seasonally flooded savannah. Our results confirm that the Llanos de Moxos is a hotspot for early plant cultivation and demonstrate that-ever since their arrival in Amazonia-humans have markedly altered the landscape, with lasting repercussions for habitat heterogeneity and species conservation.


  
Inequality has deep roots in Eurasia 期刊论文
NATURE, 2017, 551 (7682) : 573-575
作者:  Elliott, Michelle
收藏  |  浏览/下载:0/0  |  提交时间:2019/11/27
Black Death at the Golden Gate: The Race to Save America from the Bubonic Plague 期刊论文
NATURE, 2019, 568 (7753) : 454-455
作者:  Tansey, Tilli
收藏  |  浏览/下载:0/0  |  提交时间:2019/11/27
Plan S: don't ignore Latin America 期刊论文
NATURE, 2019, 573 (7775) : 495-495
作者:  Debat, Humberto;  Babini, Dominique
收藏  |  浏览/下载:0/0  |  提交时间:2019/11/27
Late-surviving stem mammal links the lowermost Cretaceous of North America and Gondwana (vol 558, pg 108, 2018) 期刊论文
NATURE, 2018, 562 (7728) : E27-E27
作者:  Huttenlocker, Adam K.;  Grossnickle, David M.;  Kirkland, James I.;  Schultz, Julia A.;  Luo, Zhe-Xi
收藏  |  浏览/下载:7/0  |  提交时间:2019/11/27
Evolutionary enhancement of Zika virus infectivity in Aedes aegypti mosquitoes 期刊论文
NATURE, 2017, 545 (7655) : 482-+
作者:  Liu, Yang;  Liu, Jianying;  Du, Senyan;  Shan, Chao;  Nie, Kaixiao;  Zhang, Rudian;  Li, Xiao-Feng;  Zhang, Renli;  Wang, Tao;  Qin, Cheng-Feng;  Wang, Penghua;  Shi, Pei-Yong;  Cheng, Gong
收藏  |  浏览/下载:13/0  |  提交时间:2019/04/09
Cutting collaborations will not put 'America first' 期刊论文
NATURE, 2017, 544 (7649) : 139-139
作者:  Maziak, Wasim
收藏  |  浏览/下载:0/0  |  提交时间:2019/04/09