نتایج جستجو برای: pleistocene

تعداد نتایج: 8977  

2016
Jeremy D. Shakun Maureen E. Raymo David W. Lea

Early Pleistocene glacial cycles in marine δO exhibit strong obliquity pacing, but there is a perplexing lack of precession variability despite its important influence on summer insolation intensity – the presumed forcing of ice sheet growth and decay according to the Milankovitch hypothesis. This puzzle has been explained in two ways: Northern Hemisphere ice sheets instead respond to insolatio...

2011
Giorgio Manzi

The origin of H. sapiens has deep roots, which include two crucial nodes: (1) the emergence and diffusion of the last common ancestor of later Homo (in the Early Pleistocene) and (2) the tempo and mode of the appearance of distinct evolutionary lineages (in the Middle Pleistocene). The window between 1,000 and 500 thousand years before present appears of crucial importance, including the genera...

2015
Jun Liu Cuimin Wang Dongli Fu Xiaoju Hu Xiangmo Xie Pengfei Liu Qiong Zhang Meng-Hua Li

Quaternary climatic changes have been recognized to influence the distribution patterns and evolutionary histories of extant organisms, but their effects on alpine species are not well understood. To investigate the Pleistocene climatic oscillations on the genetic structure of amphibians, we sequenced one mitochondrial and three nuclear DNA fragments in Nanorana parkeri, a frog endemic to the T...

Journal: :Molecular ecology 2010
Carolin A Rebernig Gerald M Schneeweiss Katharina E Bardy Peter Schönswetter Jose L Villaseñor Renate Obermayer Tod F Stuessy Hanna Weiss-Schneeweiss

Pleistocene climatic fluctuations had major impacts on desert biota in southwestern North America. During cooler and wetter periods, drought-adapted species were isolated into refugia, in contrast to expansion of their ranges during the massive aridification in the Holocene. Here, we use Melampodium leucanthum (Asteraceae), a species of the North American desert and semi-desert regions, to inve...

2013
Donald A. McFarlane Joyce Lundberg DONALD A. MCFARLANE JOYCE LUNDBERG

A middle Pleistocene age and biogeography for the extinct rodent Megalomys curazensis from Curacao, Netherlands Antilles.

F. Zarei H. Hosseinzadeh Sahafi S. Farivar, Z. Jalil-Piran

The Japanese threadfin bream, Nemipterus japonicus, the most abundant and crucially economic Nemipterus species is widespread throughout the Indo-West Pacific. The species has been studied widely for various aspects but genetic studies are scanty. This preliminary study contributes to the species phylogeography through the study of the genetic diversity and historical demography of N. japonicus...

2017
Michał Grabowski Tomasz Mamos Karolina Bącela-Spychalska Tomasz Rewicz Remi A. Wattier

BACKGROUND The Balkans are a major worldwide biodiversity and endemism hotspot. Among the freshwater biota, amphipods are known for their high cryptic diversity. However, little is known about the temporal and paleogeographic aspects of their evolutionary history. We used paleogeography as a framework for understanding the onset of diversification in Gammarus roeselii: (1) we hypothesised that,...

2017
Frido Welker Geoff M Smith Jarod M Hutson Lutz Kindler Alejandro Garcia-Moreno Aritza Villaluenga Elaine Turner Sabine Gaudzinski-Windheuser

BACKGROUND Ancient protein sequences are increasingly used to elucidate the phylogenetic relationships between extinct and extant mammalian taxa. Here, we apply these recent developments to Middle Pleistocene bone specimens of the rhinoceros genus Stephanorhinus. No biomolecular sequence data is currently available for this genus, leaving phylogenetic hypotheses on its evolutionary relationship...

1999

Artificial fill (Holocene)—Mud, sand, and gravel of varying proportions, possibly including foreign debris such as concrete, logs, timbers, or brick. Used for highway roadbeds and other construction. Thickness generally greater than 2 m. Mapped where fill substantially obscures or has altered original geologic deposit. Beach deposits (Holocene)—Soft sand, silt, and mud deposited or reworked by ...

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