The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Mietje Germonpré - One of the best experts on this subject based on the ideXlab platform.
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ancient dna suggests modern wolves trace their origin to a Late Pleistocene expansion from beringia
Molecular Ecology, 2020Co-Authors: Liisa Loog, Mietje Germonpré, Olaf Thalmann, Mikkelholger S Sinding, Verena J Schuenemann, Angela R Perri, Herve BocherensAbstract:Grey wolves (Canis lupus) are one of the few large terrestrial carnivores that have maintained a wide geographical distribution across the Northern Hemisphere throughout the Pleistocene and Holocene. Recent genetic studies have suggested that, despite this continuous presence, major demographic changes occurred in wolf populations between the Late Pleistocene and early Holocene, and that extant wolves trace their ancestry to a single Late Pleistocene population. Both the geographical origin of this ancestral population and how it became widespread remain unknown. Here, we used a spatially and temporally explicit modelling framework to analyse a data set of 90 modern and 45 ancient mitochondrial wolf genomes from across the Northern Hemisphere, spanning the last 50,000 years. Our results suggest that contemporary wolf populations trace their ancestry to an expansion from Beringia at the end of the Last Glacial Maximum, and that this process was most likely driven by Late Pleistocene ecological fluctuations that occurred across the Northern Hemisphere. This study provides direct ancient genetic evidence that long-range migration has played an important role in the population history of a large carnivore, and provides insight into how wolves survived the wave of megafaunal extinctions at the end of the last glaciation. Moreover, because Late Pleistocene grey wolves were the likely source from which all modern dogs trace their origins, the demographic history described in this study has fundamental implications for understanding the geographical origin of the dog.
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modern wolves trace their origin to a Late Pleistocene expansion from beringia
bioRxiv, 2018Co-Authors: Liisa Loog, Olaf Thalmann, Mikkelholger S Sinding, Verena J Schuenemann, Angela R Perri, Mietje GermonpréAbstract:Grey wolves (Canis lupus) are one of the few large terrestrial carnivores that maintained a wide geographic distribution across the Northern Hemisphere throughout the Pleistocene and Holocene. Recent genetic studies have suggested that, despite this continuous presence, major demographic changes occurred in wolf populations between the Late Pleistocene and early Holocene, and that extant wolves trace their ancestry to a single Late Pleistocene population. Both the geographic origin of this ancestral population and how it became widespread remain a mystery. Here we analyzed a large dataset of novel modern and ancient mitochondrial wolf genomes, spanning the last 50,000 years, using a spatially and temporally explicit modeling framework to show that contemporary wolf populations across the globe trace their ancestry to an expansion from Beringia at the end of the Last Glacial Maximum - a process most likely driven by the significant ecological changes that occurred across the Northern Hemisphere during this period. This study provides direct ancient genetic evidence that long-range migration has played an important role in the population history of a large carnivore and provides an insight into how wolves survived the wave of megafaunal extinctions at the end of the last glaciation. Moreover, because Late Pleistocene grey wolves were the likely source from which all modern dogs trace their origins, the demographic history described in this study has fundamental implications for understanding the geographical origin of the dog.
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Nonreceding hare lines: genetic continuity since the Late Pleistocene in European mountain hares (Lepus timidus)
Biological Journal of the Linnean Society, 2017Co-Authors: Steve Smith, Edson Sandoval-castellanos, Vendela K. Lagerholm, Hannes Napierala, Mikhail V. Sablin, Johanna Von Seth, Florian A. Fladerer, Mietje Germonpré, Piotr Wojtal, Rebecca MillerAbstract:Nonreceding hare lines : genetic continuity since the Late Pleistocene in European mountain hares (Lepus timidus)
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serial population extinctions in a small mammal indicate Late Pleistocene ecosystem instability
Proceedings of the National Academy of Sciences of the United States of America, 2012Co-Authors: Selina Brace, Mietje Germonpré, Rebecca Miller, Eleftheria Palkopoulou, Love Dalen, Adrian M Lister, Marcel Otte, Simon Blockley, John R Stewart, Ian BarnesAbstract:The Late Pleistocene global extinction of many terrestrial mammal species has been a subject of intensive scientific study for over a century, yet the relative contributions of environmental changes and the global expansion of humans remain unresolved. A defining component of these extinctions is a bias toward large species, with the majority of small-mammal taxa apparently surviving into the present. Here, we investigate the population-level history of a key tundra-specialist small mammal, the collared lemming (Dicrostonyx torquatus), to explore whether events during the Late Pleistocene had a discernible effect beyond the large mammal fauna. Using ancient DNA techniques to sample across three sites in North-West Europe, we observe a dramatic reduction in genetic diversity in this species over the last 50,000 y. We further identify a series of extinction-recolonization events, indicating a previously unrecognized instability in Late Pleistocene small-mammal populations, which we link with climatic fluctuations. Our results reveal climate-associated, repeated regional extinctions in a keystone prey species across the Late Pleistocene, a pattern likely to have had an impact on the wider steppe-tundra community, and one that is concordant with environmental change as a major force in structuring Late Pleistocene biodiversity.
Nick Blegen - One of the best experts on this subject based on the ideXlab platform.
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Late Pleistocene mammals from kibogo kenya systematic paleontology paleoenvironments and non analog associations
Journal of Vertebrate Paleontology, 2020Co-Authors: Tyler J Faith, Nick Blegen, John Rowan, Kaedan Obrien, Daniel J. PeppeAbstract:We report on the Late Pleistocene (36–12 ka) mammals from Kibogo in the Nyanza Rift of western Kenya, providing (1) a systematic description of the mammal remains, (2) an assessment of their paleoe...
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the menengai tuff a 36 ka widespread tephra and its chronological relevance to Late Pleistocene human evolution in east africa
Quaternary Science Reviews, 2016Co-Authors: Nick Blegen, Tyler J Faith, Francis H Brown, Brian R Jicha, Katie M Binetti, Joseph V Ferraro, Patrick N Gathogo, Jonathan L Richardson, Christian A. TryonAbstract:Abstract The East African Rift preserves the world's richest Middle and Late Pleistocene (∼780–12 ka) geological, archaeological and paleontological archives relevant to the emergence of Homo sapiens . This region also provides unparalleled chronological control for many important sites through tephrochronology, the dating and correlation of volcanic ashes as widespread isochronous markers in the geological record. There are many well-characterized Pliocene-Early Pleistocene tephras that are widespread across East Africa. A comparable framework is lacking for the Middle and Late Pleistocene; a period characterized by spatially and temporally complex patterns of climate change, as well as the emergence of modern Homo sapiens and the dispersal of this species across and out of Africa. Unraveling relationships among these spatial and temporally complex phenomena requires a precise chronology. To this end we report the Menengai Tuff, a widespread volcanic ash produced by the large-scale caldera-forming eruption in Kenya and 40 Ar/ 39 Ar dated to 35.62 ± 0.26 ka. Geochemical characterization of 565 glass shards from 36 samples by wavelength-dispersive electron probe microanalysis show the Menengai Tuff was deposited over >115,000 km 2 and is found in the Baringo, Chalbi, Elmenteita, Nakuru, Olorgesailie, Turkana, and Victoria basins, all of which preserve rich Late Pleistocene paleoenvironmental and archaeological archives. Correlation and dating of the Menengai Tuff demonstrate that it is the most widespread tephra and largest eruption currently known from the Late Pleistocene of East Africa. As such, it is a valuable marker in establishing a Late Pleistocene chronology for paleoclimatic, archeological, and paleontological records relevant to the study of human evolution.
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Biogeographic and Evolutionary Implications of an Extinct Late Pleistocene Impala from the Lake Victoria Basin, Kenya
Journal of Mammalian Evolution, 2014Co-Authors: J. Tyler Faith, Christian A. Tryon, Daniel J. Peppe, Emily J. Beverly, Nick BlegenAbstract:This study contributes to the growing complexity of the impala fossil record through a morphological description and analysis of Aepyceros fossils from Late Pleistocene deposits in Kenya’s Lake Victoria Basin. We show that the Lake Victoria impala belongs to an extinct species that differs from modern impala and its fossil predecessors by a combination of exceptionally deep mandibles and teeth characterized by greater hypsodonty and occlusal lengths. Whereas modern impala ( A. melampus ) displays substantial ecological flexibility, these traits in the extinct species suggest a more dedicated adaptation to grazing in open and dry environments. Previous phylogeographic observations indicate that A. melampus was extirpated from East Africa, perhaps during the middle-to-Late Pleistocene, and Later recolonized from southern Africa. The Lake Victoria impala raises the possibility that the evidence interpreted as extirpation may instead reflect speciation, with A. melampus giving rise to a novel East African species while persisting unchanged in southern Africa. Increased rainfall and rising atmospheric CO_2 concentrations at the end of the Pleistocene may have played a role in the disappearance of the extinct form via habitat loss and possibly competition with the more versatile A. melampus .
Mikkelholger S Sinding - One of the best experts on this subject based on the ideXlab platform.
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ancient dna suggests modern wolves trace their origin to a Late Pleistocene expansion from beringia
Molecular Ecology, 2020Co-Authors: Liisa Loog, Mietje Germonpré, Olaf Thalmann, Mikkelholger S Sinding, Verena J Schuenemann, Angela R Perri, Herve BocherensAbstract:Grey wolves (Canis lupus) are one of the few large terrestrial carnivores that have maintained a wide geographical distribution across the Northern Hemisphere throughout the Pleistocene and Holocene. Recent genetic studies have suggested that, despite this continuous presence, major demographic changes occurred in wolf populations between the Late Pleistocene and early Holocene, and that extant wolves trace their ancestry to a single Late Pleistocene population. Both the geographical origin of this ancestral population and how it became widespread remain unknown. Here, we used a spatially and temporally explicit modelling framework to analyse a data set of 90 modern and 45 ancient mitochondrial wolf genomes from across the Northern Hemisphere, spanning the last 50,000 years. Our results suggest that contemporary wolf populations trace their ancestry to an expansion from Beringia at the end of the Last Glacial Maximum, and that this process was most likely driven by Late Pleistocene ecological fluctuations that occurred across the Northern Hemisphere. This study provides direct ancient genetic evidence that long-range migration has played an important role in the population history of a large carnivore, and provides insight into how wolves survived the wave of megafaunal extinctions at the end of the last glaciation. Moreover, because Late Pleistocene grey wolves were the likely source from which all modern dogs trace their origins, the demographic history described in this study has fundamental implications for understanding the geographical origin of the dog.
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modern wolves trace their origin to a Late Pleistocene expansion from beringia
bioRxiv, 2018Co-Authors: Liisa Loog, Olaf Thalmann, Mikkelholger S Sinding, Verena J Schuenemann, Angela R Perri, Mietje GermonpréAbstract:Grey wolves (Canis lupus) are one of the few large terrestrial carnivores that maintained a wide geographic distribution across the Northern Hemisphere throughout the Pleistocene and Holocene. Recent genetic studies have suggested that, despite this continuous presence, major demographic changes occurred in wolf populations between the Late Pleistocene and early Holocene, and that extant wolves trace their ancestry to a single Late Pleistocene population. Both the geographic origin of this ancestral population and how it became widespread remain a mystery. Here we analyzed a large dataset of novel modern and ancient mitochondrial wolf genomes, spanning the last 50,000 years, using a spatially and temporally explicit modeling framework to show that contemporary wolf populations across the globe trace their ancestry to an expansion from Beringia at the end of the Last Glacial Maximum - a process most likely driven by the significant ecological changes that occurred across the Northern Hemisphere during this period. This study provides direct ancient genetic evidence that long-range migration has played an important role in the population history of a large carnivore and provides an insight into how wolves survived the wave of megafaunal extinctions at the end of the last glaciation. Moreover, because Late Pleistocene grey wolves were the likely source from which all modern dogs trace their origins, the demographic history described in this study has fundamental implications for understanding the geographical origin of the dog.
James Blinkhorn - One of the best experts on this subject based on the ideXlab platform.
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Late Pleistocene to holocene human palaeoecology in the tropical environments of coastal eastern africa
Palaeogeography Palaeoclimatology Palaeoecology, 2020Co-Authors: James Blinkhorn, Patrick Roberts, Mary E Prendergast, Anneke Janzen, Ceri Shipton, Jana Zech, Alison CrowtherAbstract:Abstract The ecological adaptations that stimuLated the dispersal and technological strategies of our species during the Late Pleistocene remain hotly disputed, with some influential theories focusing on grassland biomes or marine resources as key drivers behind the rapid expansion and material culture innovations of Homo sapiens within and beyond Africa. Here, we present novel chronologically resolved, zooarchaeological taxonomic and taphonomic analysis, and stable isotope analysis of human and faunal tooth enamel, from the site of Panga ya Saidi (c. 78–0.4 ka), Kenya. Zooarchaeological data provide rare insights into the fauna associated with, and utilized by, Late Pleistocene-Holocene human populations in tropical coastal eastern Africa. Combined zooarchaeological and faunal stable isotope data provide some of the only dated, ‘on-site’ archives of palaeoenvironments beyond the arid interior of eastern Africa for this time period, while stable isotope analysis of humans provides direct snapshots of the dietary reliance of foragers at the site. Results demonstrate that humans consistently utilized tropical forest and grassland biomes throughout the period of site occupation, through a transition from Middle Stone Age to Later Stone Age technological industries and the arrival of agriculture in the region. By contrast, while coastal resources were obtained for use in symbolic material culture, there is limited evidence for consumption of marine resources until the Holocene. We argue that the ecotonal or heterogeneous environments of coastal eastern Africa may have represented an important refugium for populations during the increasing climatic variability of the Late Pleistocene and Holocene, and that tropical environments were one of a diverse series of ecosystems exploited by H. sapiens in Africa at the dawn of global migrations.
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environments and cultural change in the indian subcontinent implications for the dispersal of homo sapiens in the Late Pleistocene
Current Anthropology, 2017Co-Authors: James Blinkhorn, Michael D PetragliaAbstract:The Indian subcontinent lies on a key east-west corridor for hominin expansions across Asia, which has led to it playing a prominent role in debate surrounding the dispersal of modern humans. The current geography and ecology of the region consists of a diverse array of habitats. An examination of changes in monsoonal intensity indicates that geographic reconfiguration of ecological diversity occurred, but at a regional level, South Asia is shown to provide suitable environments for hominin occupations throughout the Late Pleistocene. Unfortunately, the fossil record of South Asia remains poor, preventing decisive resolution of modern human dispersal debates. However, in the past decade new interdisciplinary approaches to the archaeological record have overhauled the framework for understanding behavioral change during the Late Pleistocene. While the nature of the Late Acheulean to Middle Paleolithic transition remains to be resolved, it is now clear that it appears significantly Later than in other Old W...
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ostrich expansion into india during the Late Pleistocene implications for continental dispersal corridors
Palaeogeography Palaeoclimatology Palaeoecology, 2015Co-Authors: James Blinkhorn, Hema Achyuthan, Michael D PetragliaAbstract:Abstract New evidence is presented for the earliest occurrence of ostrich (Struthio sp.) in India during the Late Pleistocene along with a synthesis on the evidence for ostrich populations in the subcontinent. Direct dating of ostrich eggshell using Accelerator Mass Spectrometry (AMS) radiocarbon methods on excavated samples from Katoati, Rajasthan, India is supported by Optically StimuLated Luminescence (OSL) dating of associated sediments to demonstrate the arrival of ostrich in India before 60 thousand years ago (ka). In addition, the first stable isotope studies on ostrich eggshell from India have been conducted, yielding a new form of palaeoenvironmental proxy data for the Late Pleistocene. The geographic expansion of ostrich into India corresponds with the distribution of Sahel-like environments, bordering but not substantially colonising endemic Indian vegetation zones. The dispersal of ostrich into India marks a rare introduction of megafauna into the subcontinent during the Late Pleistocene, the longevity of which spans a period more than 40 ka. The timespan and range of this colonisation indicate the availability and exploitation of suitable habitats in India. The continental dispersal of ostrich into India during the Late Pleistocene offers useful insights into the debate surrounding the dispersal of modern humans, and contrasts with the hypothesized coastal movement of Homo sapiens into India.
Christian A. Tryon - One of the best experts on this subject based on the ideXlab platform.
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the menengai tuff a 36 ka widespread tephra and its chronological relevance to Late Pleistocene human evolution in east africa
Quaternary Science Reviews, 2016Co-Authors: Nick Blegen, Tyler J Faith, Francis H Brown, Brian R Jicha, Katie M Binetti, Joseph V Ferraro, Patrick N Gathogo, Jonathan L Richardson, Christian A. TryonAbstract:Abstract The East African Rift preserves the world's richest Middle and Late Pleistocene (∼780–12 ka) geological, archaeological and paleontological archives relevant to the emergence of Homo sapiens . This region also provides unparalleled chronological control for many important sites through tephrochronology, the dating and correlation of volcanic ashes as widespread isochronous markers in the geological record. There are many well-characterized Pliocene-Early Pleistocene tephras that are widespread across East Africa. A comparable framework is lacking for the Middle and Late Pleistocene; a period characterized by spatially and temporally complex patterns of climate change, as well as the emergence of modern Homo sapiens and the dispersal of this species across and out of Africa. Unraveling relationships among these spatial and temporally complex phenomena requires a precise chronology. To this end we report the Menengai Tuff, a widespread volcanic ash produced by the large-scale caldera-forming eruption in Kenya and 40 Ar/ 39 Ar dated to 35.62 ± 0.26 ka. Geochemical characterization of 565 glass shards from 36 samples by wavelength-dispersive electron probe microanalysis show the Menengai Tuff was deposited over >115,000 km 2 and is found in the Baringo, Chalbi, Elmenteita, Nakuru, Olorgesailie, Turkana, and Victoria basins, all of which preserve rich Late Pleistocene paleoenvironmental and archaeological archives. Correlation and dating of the Menengai Tuff demonstrate that it is the most widespread tephra and largest eruption currently known from the Late Pleistocene of East Africa. As such, it is a valuable marker in establishing a Late Pleistocene chronology for paleoclimatic, archeological, and paleontological records relevant to the study of human evolution.
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Late Pleistocene age and archaeological context for the hominin calvaria from gvjm 22 lukenya hill kenya
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Christian A. Tryon, Tyler J Faith, Isabelle Crevecoeur, Ravid Ekshtain, Joelle Nivens, David B Patterson, Emma Mbua, Fred SpoorAbstract:Kenya National Museums Lukenya Hill Hominid 1 (KNM-LH 1) is a Homo sapiens partial calvaria from site GvJm-22 at Lukenya Hill, Kenya, associated with Later Stone Age (LSA) archaeological deposits. KNM-LH 1 is securely dated to the Late Pleistocene, and samples a time and region important for understanding the origins of modern human diversity. A revised chronology based on 26 accelerator mass spectrometry radiocarbon dates on ostrich eggshells indicates an age range of 23,576-22,887 y B.P. for KNM-LH 1, confirming prior attribution to the Last Glacial Maximum. Additional dates extend the maximum age for archaeological deposits at GvJm-22 to >46,000 y B.P. (>46 kya). These dates are consistent with new analyses identifying both Middle Stone Age and LSA lithic technologies at the site, making GvJm-22 a rare eastern African record of major human behavioral shifts during the Late Pleistocene. Comparative morphometric analyses of the KNM-LH 1 cranium document the temporal and spatial complexity of early modern human morphological variability. Features of cranial shape distinguish KNM-LH 1 and other Middle and Late Pleistocene African fossils from crania of recent Africans and samples from Holocene LSA and European Upper Paleolithic sites.
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Biogeographic and Evolutionary Implications of an Extinct Late Pleistocene Impala from the Lake Victoria Basin, Kenya
Journal of Mammalian Evolution, 2014Co-Authors: J. Tyler Faith, Christian A. Tryon, Daniel J. Peppe, Emily J. Beverly, Nick BlegenAbstract:This study contributes to the growing complexity of the impala fossil record through a morphological description and analysis of Aepyceros fossils from Late Pleistocene deposits in Kenya’s Lake Victoria Basin. We show that the Lake Victoria impala belongs to an extinct species that differs from modern impala and its fossil predecessors by a combination of exceptionally deep mandibles and teeth characterized by greater hypsodonty and occlusal lengths. Whereas modern impala ( A. melampus ) displays substantial ecological flexibility, these traits in the extinct species suggest a more dedicated adaptation to grazing in open and dry environments. Previous phylogeographic observations indicate that A. melampus was extirpated from East Africa, perhaps during the middle-to-Late Pleistocene, and Later recolonized from southern Africa. The Lake Victoria impala raises the possibility that the evidence interpreted as extirpation may instead reflect speciation, with A. melampus giving rise to a novel East African species while persisting unchanged in southern Africa. Increased rainfall and rising atmospheric CO_2 concentrations at the end of the Pleistocene may have played a role in the disappearance of the extinct form via habitat loss and possibly competition with the more versatile A. melampus .
