نتایج جستجو برای: pleistocene

تعداد نتایج: 8977  

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2007
M Martinón-Torres J M Bermúdez de Castro A Gómez-Robles J L Arsuaga E Carbonell D Lordkipanidze G Manzi A Margvelashvili

A common assumption in the evolutionary scenario of the first Eurasian hominin populations is that they all had an African origin. This assumption also seems to apply for the Early and Middle Pleistocene populations, whose presence in Europe has been largely explained by a discontinuous flow of African emigrant waves. Only recently, some voices have speculated about the possibility of Asia bein...

2017
Daniel J. Hill Kevin P. Bolton Alan M. Haywood

The Earth underwent a major transition from the warm climates of the Pliocene to the Pleistocene ice ages between 3.2 and 2.6 million years ago. The intensification of Northern Hemisphere Glaciation is the most obvious result of the Plio-Pleistocene transition. However, recent data show that the ocean also underwent a significant change, with the convergence of deep water mass properties in the...

2013
Eleftheria Palkopoulou Love Dalén Adrian M. Lister Sergey Vartanyan Mikhail Sablin Andrei Sher Veronica Nyström Edmark Mikael D. Brandström Mietje Germonpré Ian Barnes Jessica A. Thomas

Ancient DNA analyses have provided enhanced resolution of population histories in many Pleistocene taxa. However, most studies are spatially restricted, making inference of species-level biogeographic histories difficult. Here, we analyse mitochondrial DNA (mtDNA) variation in the woolly mammoth from across its Holarctic range to reconstruct its history over the last 200 thousand years (kyr). W...

Journal: :Trends in ecology & evolution 2005
Irby J Lovette

How old are most species of North American birds? A longstanding debate centers on whether Pleistocene events caused substantial avian diversification. Two new syntheses of speciation times by Johnson and Cicero, and Weir and Schluter provide compelling evidence of recent Pleistocene speciation, whereas diversification rate analyses by Zink et al. suggest that most speciation events occurred ea...

2006
C. Loehle

Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion EGU Abstract Climates at the Last Glacial Maximum have been inferred from fossil pollen assemblages , but these inferred climates are colder than those produced by climate simulations. Biogeographic evidence also argues against these inferred cold climates. The recolon...

2015
S. Markovic U. G. Wortmann

Introduction Conclusions References

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2000
J A Leonard R K Wayne A Cooper

The Pleistocene was a dynamic period for Holarctic mammal species, complicated by episodes of glaciation, local extinctions, and intercontinental migration. The genetic consequences of these events are difficult to resolve from the study of present-day populations. To provide a direct view of population genetics in the late Pleistocene, we measured mitochondrial DNA sequence variation in seven ...

2004
S. Kathleen Lyons Felisa A. Smith James H. Brown

Numerous anthropological and ecological hypotheses have been proposed to explain the extinction of many large-bodied mammals at the terminal Pleistocene. We find that body size distributions of all mammals in North America, South America, Africa and Australia before and after the late Pleistocene show a similar large-size selectivity of extinctions across continents, despite differences in timi...

2013
Hong Ao Mark J. Dekkers Qi Wei Xiaoke Qiang Guoqiao Xiao

The Nihewan Basin in North China has a rich source of Early Pleistocene Paleolithic sites. Here, we report a high-resolution magnetostratigraphic dating of the Shangshazui Paleolithic site that was found in the northeastern Nihewan Basin in 1972. The artifact layer is suggested to be located in the Matuyama reversed polarity chron just above the upper boundary of the Olduvai polarity subchron, ...

2011
Amanuel Beyin

Although there is a general consensus on African origin of early modern humans, there is disagreement about how and when they dispersed to Eurasia. This paper reviews genetic and Middle Stone Age/Middle Paleolithic archaeological literature from northeast Africa, Arabia, and the Levant to assess the timing and geographic backgrounds of Upper Pleistocene human colonization of Eurasia. At the cen...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید