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Armstrong E, Tallavaara M, Hopcroft PO, Valdes PJ. North African humid periods over the past 800,000 years. Nat Commun 2023; 14:5549. [PMID: 37684244 PMCID: PMC10491769 DOI: 10.1038/s41467-023-41219-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 08/24/2023] [Indexed: 09/10/2023] Open
Abstract
The Sahara region has experienced periodic wet periods over the Quaternary and beyond. These North African Humid Periods (NAHPs) are astronomically paced by precession which controls the intensity of the African monsoon system. However, most climate models cannot reconcile the magnitude of these events and so the driving mechanisms remain poorly constrained. Here, we utilise a recently developed version of the HadCM3B coupled climate model that simulates 20 NAHPs over the past 800 kyr which have good agreement with NAHPs identified in proxy data. Our results show that precession determines NAHP pacing, but we identify that their amplitude is strongly linked to eccentricity via its control over ice sheet extent. During glacial periods, enhanced ice-albedo driven cooling suppresses NAHP amplitude at precession minima, when humid conditions would otherwise be expected. This highlights the importance of both precession and eccentricity, and the role of high latitude processes in determining the timing and amplitude of the NAHPs. This may have implications for the out of Africa dispersal of plants and animals throughout the Quaternary.
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Affiliation(s)
- Edward Armstrong
- Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland.
| | - Miikka Tallavaara
- Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
| | - Peter O Hopcroft
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Paul J Valdes
- School of Geographical Sciences, University of Bristol, Bristol, UK
- Cabot Institute, University of Bristol, Bristol, UK
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2
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Tydecks L, Hernández-Agüero JA, Böhning-Gaese K, Bremerich V, Jeschke JM, Schütt B, Zarfl C, Tockner K. Oases in the Sahara Desert-Linking biological and cultural diversity. PLoS One 2023; 18:e0290304. [PMID: 37590303 PMCID: PMC10434913 DOI: 10.1371/journal.pone.0290304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 08/05/2023] [Indexed: 08/19/2023] Open
Abstract
The diversity of life sensu lato comprises both biological and cultural diversity, described as "biocultural diversity." Similar to plant and animal species, cultures and languages are threatened by extinction. Since drylands are pivotal systems for nature and people alike, we use oases in the Sahara Desert as model systems for examining spatial patterns and trends of biocultural diversity. We identify both the underlying drivers of biodiversity and the potential proxies that are fundamental for understanding reciprocal linkages between biological and cultural diversity in oases. Using oases in Algeria as an example we test current indices describing and quantifying biocultural diversity and identify their limitations. Finally, we discuss follow-up research questions to better understand the underlying mechanisms that control the coupling and decoupling of biological and cultural diversity in oases.
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Affiliation(s)
- Laura Tydecks
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
- Freie Universität Berlin, Berlin, Germany
| | | | - Katrin Böhning-Gaese
- Faculty of Biosciences, Goethe University, Frankfurt (Main), Germany
- Senckenberg Biodiversity and Climate Research Centre (BiK-F), Frankfurt (Main), Germany
| | - Vanessa Bremerich
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
| | - Jonathan M. Jeschke
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
- Freie Universität Berlin, Berlin, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
| | | | - Christiane Zarfl
- Department of Geosciences, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Klement Tockner
- Senckenberg Gesellschaft für Naturforschung, Frankfurt (Main), Germany
- Faculty of Biosciences, Goethe University, Frankfurt (Main), Germany
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3
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L Rocha J, Silva P, Santos N, Nakamura M, Afonso S, Qninba A, Boratynski Z, Sudmant PH, Brito JC, Nielsen R, Godinho R. North African fox genomes show signatures of repeated introgression and adaptation to life in deserts. Nat Ecol Evol 2023; 7:1267-1286. [PMID: 37308700 PMCID: PMC10527534 DOI: 10.1038/s41559-023-02094-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 04/26/2023] [Indexed: 06/14/2023]
Abstract
Elucidating the evolutionary process of animal adaptation to deserts is key to understanding adaptive responses to climate change. Here we generated 82 individual whole genomes of four fox species (genus Vulpes) inhabiting the Sahara Desert at different evolutionary times. We show that adaptation of new colonizing species to a hot arid environment has probably been facilitated by introgression and trans-species polymorphisms shared with older desert resident species, including a putatively adaptive 25 Mb genomic region. Scans for signatures of selection implicated genes affecting temperature perception, non-renal water loss and heat production in the recent adaptation of North African red foxes (Vulpes vulpes), after divergence from Eurasian populations approximately 78 thousand years ago. In the extreme desert specialists, Rueppell's fox (V. rueppellii) and fennec (V. zerda), we identified repeated signatures of selection in genes affecting renal water homeostasis supported by gene expression and physiological differences. Our study provides insights into the mechanisms and genetic underpinnings of a natural experiment of repeated adaptation to extreme conditions.
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Affiliation(s)
- Joana L Rocha
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal.
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal.
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal.
- Department of Integrative Biology and Department of Statistics, University of California Berkeley, Berkeley, CA, USA.
| | - Pedro Silva
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
| | - Nuno Santos
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
| | - Mónia Nakamura
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
| | - Sandra Afonso
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
| | - Abdeljebbar Qninba
- Laboratory of Geophysics and Natural Hazards, Geophysics, Natural Patrimony and Green Chemistry Research Center (GEOPAC), Institut Scientifique, Mohammed V University of Rabat, Rabat, Morocco
| | - Zbyszek Boratynski
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
| | - Peter H Sudmant
- Department of Integrative Biology and Department of Statistics, University of California Berkeley, Berkeley, CA, USA
- Center for Computational Biology, University of California, Berkeley, CA, USA
| | - José C Brito
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
| | - Rasmus Nielsen
- Department of Integrative Biology and Department of Statistics, University of California Berkeley, Berkeley, CA, USA.
- Center for Computational Biology, University of California, Berkeley, CA, USA.
- Globe Institute, University of Copenhagen, Copenhagen, Denmark.
| | - Raquel Godinho
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal.
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal.
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal.
- Department of Zoology, University of Johannesburg, Auckland Park, South Africa.
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Kandel AW, Sommer C, Kanaeva Z, Bolus M, Bruch AA, Groth C, Haidle MN, Hertler C, Heß J, Malina M, Märker M, Hochschild V, Mosbrugger V, Schrenk F, Conard NJ. The ROCEEH Out of Africa Database (ROAD): A large-scale research database serves as an indispensable tool for human evolutionary studies. PLoS One 2023; 18:e0289513. [PMID: 37527270 PMCID: PMC10393170 DOI: 10.1371/journal.pone.0289513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 07/19/2023] [Indexed: 08/03/2023] Open
Abstract
Large scale databases are critical for helping scientists decipher long-term patterns in human evolution. This paper describes the conception and development of such a research database and illustrates how big data can be harnessed to formulate new ideas about the past. The Role of Culture in Early Expansions of Humans (ROCEEH) is a transdisciplinary research center whose aim is to study the origins of culture and the multifaceted aspects of human expansions across Africa and Eurasia over the last three million years. To support its research, the ROCEEH team developed an online tool named the ROCEEH Out of Africa Database (ROAD) and implemented its web-based applications. ROAD integrates geographical data as well as archaeological, paleoanthropological, paleontological and paleobotanical content within a robust chronological framework. In fact, a unique feature of ROAD is its ability to dynamically link scientific data both spatially and temporally, thereby allowing its reuse in ways that were not originally conceived. The data stem from published sources spanning the last 150 years, including those generated by the research team. Descriptions of these data rely on the development of a standardized vocabulary and profit from online explanations of each table and attribute. By synthesizing legacy data, ROAD facilitates the reuse of heritage data in novel ways. Database queries yield structured information in a variety of interoperable formats. By visualizing data on maps, users can explore this vast dataset and develop their own theories. By downloading data, users can conduct further quantitative analyses, for example with Geographic Information Systems, modeling programs and artificial intelligence. In this paper, we demonstrate the innovative nature of ROAD and show how it helps scientists studying human evolution to access datasets from different fields, thereby connecting the social and natural sciences. Because it permits the reuse of "old" data in new ways, ROAD is now an indispensable tool for researchers of human evolution and paleogeography.
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Affiliation(s)
- Andrew W Kandel
- The Role of Culture in Early Expansions of Humans, Heidelberg Academy of Sciences and Humanities, Tübingen, Germany
| | - Christian Sommer
- The Role of Culture in Early Expansions of Humans, Heidelberg Academy of Sciences and Humanities, Tübingen, Germany
| | - Zara Kanaeva
- The Role of Culture in Early Expansions of Humans, Heidelberg Academy of Sciences and Humanities, Tübingen, Germany
| | - Michael Bolus
- The Role of Culture in Early Expansions of Humans, Heidelberg Academy of Sciences and Humanities, Tübingen, Germany
- Department of Geosciences, Working Group Early Prehistory and Quaternary Ecology, University of Tübingen, Tübingen, Germany
| | - Angela A Bruch
- The Role of Culture in Early Expansions of Humans, Senckenberg Forschungsinstitut, Heidelberg Academy of Sciences and Humanities, Frankfurt/Main, Germany
| | - Claudia Groth
- The Role of Culture in Early Expansions of Humans, Senckenberg Forschungsinstitut, Heidelberg Academy of Sciences and Humanities, Frankfurt/Main, Germany
| | - Miriam N Haidle
- Department of Geosciences, Working Group Early Prehistory and Quaternary Ecology, University of Tübingen, Tübingen, Germany
- The Role of Culture in Early Expansions of Humans, Senckenberg Forschungsinstitut, Heidelberg Academy of Sciences and Humanities, Frankfurt/Main, Germany
| | - Christine Hertler
- The Role of Culture in Early Expansions of Humans, Senckenberg Forschungsinstitut, Heidelberg Academy of Sciences and Humanities, Frankfurt/Main, Germany
| | - Julia Heß
- The Role of Culture in Early Expansions of Humans, Senckenberg Forschungsinstitut, Heidelberg Academy of Sciences and Humanities, Frankfurt/Main, Germany
| | - Maria Malina
- The Role of Culture in Early Expansions of Humans, Heidelberg Academy of Sciences and Humanities, Tübingen, Germany
| | - Michael Märker
- Department of Earth and Environmental Sciences, University of Pavia, Pavia, Italy
- Working Group on "Soil Erosion and Feedbacks", Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany
| | - Volker Hochschild
- Institute of Geography, Department of Geosciences, University of Tübingen, Tübingen, Germany
| | - Volker Mosbrugger
- The Role of Culture in Early Expansions of Humans, Senckenberg Forschungsinstitut, Heidelberg Academy of Sciences and Humanities, Frankfurt/Main, Germany
| | - Friedemann Schrenk
- The Role of Culture in Early Expansions of Humans, Senckenberg Forschungsinstitut, Heidelberg Academy of Sciences and Humanities, Frankfurt/Main, Germany
| | - Nicholas J Conard
- Department of Geosciences, Working Group Early Prehistory and Quaternary Ecology, University of Tübingen, Tübingen, Germany
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Hempel E, Westbury MV, Grau JH, Trinks A, Paijmans JLA, Kliver S, Barlow A, Mayer F, Müller J, Chen L, Koepfli KP, Hofreiter M, Bibi F. Diversity and Paleodemography of the Addax ( Addax nasomaculatus), a Saharan Antelope on the Verge of Extinction. Genes (Basel) 2021; 12:genes12081236. [PMID: 34440410 PMCID: PMC8394336 DOI: 10.3390/genes12081236] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 08/05/2021] [Accepted: 08/08/2021] [Indexed: 12/18/2022] Open
Abstract
Since the 19th century, the addax (Addax nasomaculatus) has lost approximately 99% of its former range. Along with its close relatives, the blue antelope (Hippotragus leucophaeus) and the scimitar-horned oryx (Oryx dammah), the addax may be the third large African mammal species to go extinct in the wild in recent times. Despite this, the evolutionary history of this critically endangered species remains virtually unknown. To gain insight into the population history of the addax, we used hybridization capture to generate ten complete mitochondrial genomes from historical samples and assembled a nuclear genome. We found that both mitochondrial and nuclear diversity are low compared to other African bovids. Analysis of mitochondrial genomes revealed a most recent common ancestor ~32 kya (95% CI 11–58 kya) and weak phylogeographic structure, indicating that the addax likely existed as a highly mobile, panmictic population across its Sahelo–Saharan range in the past. PSMC analysis revealed a continuous decline in effective population size since ~2 Ma, with short intermediate increases at ~500 and ~44 kya. Our results suggest that the addax went through a major bottleneck in the Late Pleistocene, remaining at low population size prior to the human disturbances of the last few centuries.
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Affiliation(s)
- Elisabeth Hempel
- Evolutionary Adaptive Genomics, Institute of Biochemistry and Biology, Faculty of Science, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany; (J.H.G.); (M.H.)
- Museum für Naturkunde, Berlin, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany; (F.M.); (J.M.); (F.B.)
- Correspondence:
| | - Michael V. Westbury
- Evolutionary Adaptive Genomics, Institute of Biochemistry and Biology, Faculty of Science, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany; (J.H.G.); (M.H.)
- Section for Evolutionary Genomics, The GLOBE Institute, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen, Denmark;
| | - José H. Grau
- Evolutionary Adaptive Genomics, Institute of Biochemistry and Biology, Faculty of Science, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany; (J.H.G.); (M.H.)
- Museum für Naturkunde, Berlin, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany; (F.M.); (J.M.); (F.B.)
| | - Alexandra Trinks
- Evolutionary Adaptive Genomics, Institute of Biochemistry and Biology, Faculty of Science, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany; (J.H.G.); (M.H.)
- Institute of Pathology, Charité–Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany;
| | - Johanna L. A. Paijmans
- Evolutionary Adaptive Genomics, Institute of Biochemistry and Biology, Faculty of Science, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany; (J.H.G.); (M.H.)
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK;
| | - Sergei Kliver
- Institute of Molecular and Cellular Biology SB RAS, 8/2 Acad. Lavrentiev Ave, 630090 Novosibirsk, Russia;
| | - Axel Barlow
- Evolutionary Adaptive Genomics, Institute of Biochemistry and Biology, Faculty of Science, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany; (J.H.G.); (M.H.)
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK;
| | - Frieder Mayer
- Museum für Naturkunde, Berlin, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany; (F.M.); (J.M.); (F.B.)
| | - Johannes Müller
- Museum für Naturkunde, Berlin, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany; (F.M.); (J.M.); (F.B.)
| | - Lei Chen
- School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710072, China;
| | - Klaus-Peter Koepfli
- Smithsonian-Mason School of Conservation, George Mason University, Front Royal, VA 22630, USA;
- Smithsonian Conservation Biology Institute, Center for Species Survival, National Zoological Park, Front Royal, VA 22630, USA
- Computer Technologies Laboratory, ITMO University, 197101 Saint Petersburg, Russia
| | - Michael Hofreiter
- Evolutionary Adaptive Genomics, Institute of Biochemistry and Biology, Faculty of Science, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany; (J.H.G.); (M.H.)
| | - Faysal Bibi
- Museum für Naturkunde, Berlin, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany; (F.M.); (J.M.); (F.B.)
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Rare crested rat subfossils unveil Afro-Eurasian ecological corridors synchronous with early human dispersals. Proc Natl Acad Sci U S A 2021; 118:2105719118. [PMID: 34312232 DOI: 10.1073/pnas.2105719118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Biotic interactions between Africa and Eurasia across the Levant have invoked particular attention among scientists aiming to unravel early human dispersals. However, it remains unclear whether behavioral capacities enabled early modern humans to surpass the Saharo-Arabian deserts or if climatic changes triggered punctuated dispersals out of Africa. Here, we report an unusual subfossil assemblage discovered in a Judean Desert's cliff cave near the Dead Sea and dated to between ∼42,000 and at least 103,000 y ago. Paleogenomic and morphological comparisons indicate that the specimens belong to an extinct subspecies of the eastern African crested rat, Lophiomys imhausi maremortum subspecies nova, which diverged from the modern eastern African populations in the late Middle Pleistocene ∼226,000 to 165,000 y ago. The reported paleomitogenome is the oldest so far in the Levant, opening the door for future paleoDNA analyses in the region. Species distribution modeling points to the presence of continuous habitat corridors connecting eastern Africa with the Levant during the Last Interglacial ∼129,000 to 116,000 y ago, providing further evidence of the northern ingression of African biomes into Eurasia and reinforcing previous suggestions of the critical role of climate change in Late Pleistocene intercontinental biogeography. Furthermore, our study complements other paleoenvironmental proxies with local-instead of interregional-paleoenvironmental data, opening an unprecedented window into the Dead Sea rift paleolandscape.
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Sánchez Goñi MF. Regional impacts of climate change and its relevance to human evolution. EVOLUTIONARY HUMAN SCIENCES 2020; 2:e55. [PMID: 37588361 PMCID: PMC10427484 DOI: 10.1017/ehs.2020.56] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The traditional concept of long and gradual, glacial-interglacial climate changes during the Quaternary has been challenged since the 1980s. High temporal resolution analysis of marine, terrestrial and ice geological archives has identified rapid, millennial- to centennial-scale, and large-amplitude climatic cycles throughout the last few million years. These changes were global but have had contrasting regional impacts on the terrestrial and marine ecosystems, with in some cases strong changes in the high latitudes of both hemispheres but muted changes elsewhere. Such a regionalization has produced environmental barriers and corridors that have probably triggered niche contractions/expansions of hominin populations living in Eurasia and Africa. This article reviews the long- and short-timescale ecosystem changes that have punctuated the last few million years, paying particular attention to the environments of the last 650,000 years, which have witnessed key events in the evolution of our lineage in Africa and Eurasia. This review highlights, for the first time, a contemporaneity between the split between Denisovan and Neanderthals, at ~650-400 ka, and the strong Eurasian ice-sheet expansion down to the Black Sea. This ice expansion could form an ice barrier between Europe and Asia that may have triggered the genetic drift between these two populations.
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9
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African climate response to orbital and glacial forcing in 140,000-y simulation with implications for early modern human environments. Proc Natl Acad Sci U S A 2020; 117:2255-2264. [PMID: 31964850 DOI: 10.1073/pnas.1917673117] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A climate/vegetation model simulates episodic wetter and drier periods at the 21,000-y precession period in eastern North Africa, the Arabian Peninsula, and the Levant over the past 140,000 y. Large orbitally forced wet/dry extremes occur during interglacial time, ∼130 to 80 ka, and conditions between these two extremes prevail during glacial time, ∼70 to 15 ka. Orbital precession causes high seasonality in Northern Hemisphere (NH) insolation at ∼125, 105, and 83 ka, with stronger and northward extended summer monsoon rains in North Africa and the Arabian Peninsula and increased winter rains in the Mediterranean Basin. The combined effects of these two seasonally distinct rainfall regimes increase vegetation and narrow the width of the Saharan-Arabian desert and semidesert zones. During the opposite phase of the precession cycle (∼115, 95, and 73 ka), NH seasonality is low, and decreased summer insolation and increased winter insolation cause monsoon and storm track rains to decrease and the width of the desert zone to increase. During glacial time (∼70 to 15 ka), forcing from large ice sheets and lowered greenhouse gas concentrations combine to increase winter Mediterranean storm track precipitation; the southward retreat of the northern limit of summer monsoon rains is relatively small, thereby limiting the expansion of deserts. The lowered greenhouse gas concentrations cause the near-equatorial zone to cool and reduce convection, causing drier climate with reduced forest cover. At most locations and times, the simulations agree with environmental observations. These changing regional patterns of climate/vegetation could have influenced the dispersal of early humans through expansions and contractions of well-watered corridors.
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Mairal M, Caujapé-Castells J, Pellissier L, Jaén-Molina R, Álvarez N, Heuertz M, Sanmartín I. A tale of two forests: ongoing aridification drives population decline and genetic diversity loss at continental scale in Afro-Macaronesian evergreen-forest archipelago endemics. ANNALS OF BOTANY 2018; 122:1005-1017. [PMID: 29905771 PMCID: PMC6266103 DOI: 10.1093/aob/mcy107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 05/25/2018] [Indexed: 05/24/2023]
Abstract
BACKGROUND AND AIMS Various studies and conservationist reports have warned about the contraction of the last subtropical Afro-Macaronesian forests. These relict vegetation zones have been restricted to a few oceanic and continental islands around the edges of Africa, due to aridification. Previous studies on relict species have generally focused on glacial effects on narrow endemics; however, little is known about the effects of aridification on the fates of previously widespread subtropical lineages. METHODS Nuclear microsatellites and ecological niche modelling were used to understand observed patterns of genetic diversity in two emblematic species, widely distributed in these ecosystems: Canarina eminii (a palaeoendemic of the eastern Afromontane forests) and Canarina canariensis (a palaeoendemic of the Canarian laurel forests). The software DIYABC was used to test alternative demographic scenarios and an ensemble method was employed to model potential distributions of the selected plants from the end of the deglaciation to the present. KEY RESULTS All the populations assessed experienced a strong and recent population decline, revealing that locally widespread endemisms may also be alarmingly threatened. CONCLUSIONS The detected extinction debt, as well as the extinction spiral to which these populations are subjected, demands urgent conservation measures for the unique, biodiversity-rich ecosystems that they inhabit.
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Affiliation(s)
- Mario Mairal
- Real Jardín Botánico (RJB), CSIC, Plaza de Murillo, Madrid, Spain
- Departamento de Biodiversidad Molecular y Banco de ADN, Jardín Botánico ‘Viera y Clavijo’ – Unidad Asociada CSIC (Cabildo de Gran Canaria), Las Palmas de Gran Canaria, Spain
| | - Juli Caujapé-Castells
- Departamento de Biodiversidad Molecular y Banco de ADN, Jardín Botánico ‘Viera y Clavijo’ – Unidad Asociada CSIC (Cabildo de Gran Canaria), Las Palmas de Gran Canaria, Spain
| | - Loïc Pellissier
- Landscape Ecology, Institute of Terrestrial Ecosystems, ETH Zürich, Zürich, Switzerland
- Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - Ruth Jaén-Molina
- Departamento de Biodiversidad Molecular y Banco de ADN, Jardín Botánico ‘Viera y Clavijo’ – Unidad Asociada CSIC (Cabildo de Gran Canaria), Las Palmas de Gran Canaria, Spain
| | - Nadir Álvarez
- Department of Ecology and Evolution, Institute of Biology, University of Lausanne, Biophore Dorigny, Lausanne, Switzerland
| | | | - Isabel Sanmartín
- Real Jardín Botánico (RJB), CSIC, Plaza de Murillo, Madrid, Spain
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Langgut D, Almogi-Labin A, Bar-Matthews M, Pickarski N, Weinstein-Evron M. Evidence for a humid interval at ∼56–44 ka in the Levant and its potential link to modern humans dispersal out of Africa. J Hum Evol 2018; 124:75-90. [DOI: 10.1016/j.jhevol.2018.08.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 08/06/2018] [Accepted: 08/07/2018] [Indexed: 12/13/2022]
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Fulgione A, Hancock AM. Archaic lineages broaden our view on the history of Arabidopsis thaliana. THE NEW PHYTOLOGIST 2018; 219:1194-1198. [PMID: 29862511 DOI: 10.1111/nph.15244] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 04/25/2018] [Indexed: 05/15/2023]
Abstract
Contents Summary 1194 I. Introduction 1194 II. Origin of the A. thaliana species 1194 III. The classic model of the history of A. thaliana 1195 IV. New genomic data from outside Eurasia challenge our view of A. thaliana history 1195 V. Conclusions 1197 Acknowledgements 1197 References 1197 SUMMARY: Natural variation in Arabidopsis thaliana has contributed to discoveries in diverse areas of plant biology. While A. thaliana has typically been considered a weed associated primarily with human-mediated environments, including agricultural and urban sites and railways, it has recently been shown that it is also native in remote natural areas, including high altitude sites in Eurasia and Africa, from the Atlas mountains in Morocco to the afro-alpine regions in Eastern and South Africa to Yunnan in China, the Himalayas and the Tibetan Plateau. This finding suggests that while A. thaliana has been extensively studied in Europe and Western Asia there are still many open questions about its population history, genotype-phenotype relationships and mechanisms of adaptation.
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Affiliation(s)
- Andrea Fulgione
- Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany
| | - Angela M Hancock
- Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany
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13
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Font-Porterias N, Solé-Morata N, Serra-Vidal G, Bekada A, Fadhlaoui-Zid K, Zalloua P, Calafell F, Comas D. The genetic landscape of Mediterranean North African populations through complete mtDNA sequences. Ann Hum Biol 2018; 45:98-104. [DOI: 10.1080/03014460.2017.1413133] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Neus Font-Porterias
- Departament de Ciències Experimentals i de la Salut, Institute of Evolutionary Biology (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Neus Solé-Morata
- Departament de Ciències Experimentals i de la Salut, Institute of Evolutionary Biology (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Gerard Serra-Vidal
- Departament de Ciències Experimentals i de la Salut, Institute of Evolutionary Biology (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Asmahan Bekada
- Département de Biotechnologie, Faculté des Sciences de la Nature et de la Vie, Université Oran 1 (Ahmad Ben Bella), Oran, Algeria
| | - Karima Fadhlaoui-Zid
- Laboratoire de Génetique, Immunologie et Pathologies Humaines, Faculté des Sciences de Tunis, Campus Univesritaire El Manar II, Université El Manar, Tunis, Tunisia
| | - Pierre Zalloua
- School of Medicine, The Lebanese American University, Chouran, Beirut, Lebanon
| | - Francesc Calafell
- Departament de Ciències Experimentals i de la Salut, Institute of Evolutionary Biology (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - David Comas
- Departament de Ciències Experimentals i de la Salut, Institute of Evolutionary Biology (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
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Vaks A, Bar-Matthews M, Ayalon A, Matthews A, Frumkin A. Pliocene–Pleistocene palaeoclimate reconstruction from Ashalim Cave speleothems, Negev Desert, Israel. ACTA ACUST UNITED AC 2017. [DOI: 10.1144/sp466.10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractSpeleothems from Ashalim Cave, located in the arid central Negev Desert, Israel, were used in a reconstruction of the palaeoclimate of the northern Saharan–Arabian desert margin. The sequence of speleothems is composed of three stratigraphic members: the yellow Pliocene Basal Member, the brown Early Pleistocene Intermediate Member and the thin Middle–Late Pleistocene Young Member. The age of the Basal Member is c. 3.1 Ma and the base of the Intermediate Member is 1.272 ± 0.018 Ma. Two last deposition periods of the Young Member occurred at 221–190 ka (Negev Humid Period (NHP) 2) and 134–114 ka (NHP-1), associated with interglacial marine isotopic stages 7.3–7.1 and 5.5, respectively. NHP-1 and -2 occurred when the African monsoon index was highest in the last 221 ka. The δ18O values of the speleothems range between −6.9 and −11.2‰, 2–4‰ less than in the speleothems of central and northern Israel. This may indicate a remote southern tropical source of precipitation, although during NHP-1 and -2 the thickness of the Negev Desert speleothems decreases from north to south, showing a stronger northern Mediterranean source of moisture. The δ13C values of the speleothems (3.5 to −8.5‰) show steppe to semi-desert C4 type vegetation. The 87Sr/86Sr ratios of the speleothems increased from c. 0.7078 in the Pliocene to 0.7082–0.7085 in the Pleistocene, indicating an increasing supply of desert dust and a decrease in host rock weathering.
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Affiliation(s)
- Anton Vaks
- Geological Survey of Israel, 30 Malchei Israel Street, Jerusalem 9550161, Israel
| | - Miryam Bar-Matthews
- Geological Survey of Israel, 30 Malchei Israel Street, Jerusalem 9550161, Israel
| | - Avner Ayalon
- Geological Survey of Israel, 30 Malchei Israel Street, Jerusalem 9550161, Israel
| | - Alan Matthews
- Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Amos Frumkin
- Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
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Abstract
Homo sapiens phylogeography begins with the species' origin nearly 200 kya in Africa. First signs of the species outside Africa (in Arabia) are from 125 kya. Earliest dates elsewhere are now 100 kya in China, 45 kya in Australia and southern Europe (maybe even 60 kya in Australia), 32 kya in northeast Siberia, and maybe 20 kya in the Americas. Humans reached arctic regions and oceanic islands last-arctic North America about 5 kya, mid- and eastern Pacific islands about 2-1 kya, and New Zealand about 700 y ago. Initial routes along coasts seem the most likely given abundant and easily harvested shellfish there as indicated by huge ancient oyster shell middens on all continents. Nevertheless, the effect of geographic barriers-mountains and oceans-is clear. The phylogeographic pattern of diasporas from several single origins-northeast Africa to Eurasia, southeast Eurasia to Australia, and northeast Siberia to the Americas-allows the equivalent of a repeat experiment on the relation between geography and phylogenetic and cultural diversity. On all continents, cultural diversity is high in productive low latitudes, presumably because such regions can support populations of sustainable size in a small area, therefore allowing a high density of cultures. Of course, other factors operate. South America has an unusually low density of cultures in its tropical latitudes. A likely factor is the phylogeographic movement of peoples from the Old World bringing novel and hence, lethal diseases to the New World, a foretaste, perhaps, of present day global transport of tropical diseases.
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End-member modelling as a tool for climate reconstruction-An Eastern Mediterranean case study. PLoS One 2017; 12:e0185136. [PMID: 28934332 PMCID: PMC5608325 DOI: 10.1371/journal.pone.0185136] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 09/05/2017] [Indexed: 11/19/2022] Open
Abstract
The Eastern Mediterranean Sea is a sink for terrigenous sediments from North Africa, Europe and Asia Minor. Its sediments therefore provide valuable information on the climate dynamics in the source areas and the associated transport processes. We present a high-resolution dataset of sediment core M40/4_SL71, which was collected SW of Crete and spans the last ca. 180 kyr. We analysed the clay mineral composition, the grain size distribution within the silt fraction, and the abundance of major and trace elements. We tested the potential of end-member modelling on these sedimentological datasets as a tool for reconstructing the climate variability in the source regions and the associated detrital input. For each dataset, we modelled three end members. All end members were assigned to a specific provenance and sedimentary process. In total, three end members were related to the Saharan dust input, and five were related to the fluvial sediment input. One end member was strongly associated with the sapropel layers. The Saharan dust end members of the grain size and clay mineral datasets generally suggest enhanced dust export into the Eastern Mediterranean Sea during the dry phases with short-term increases during Heinrich events. During the African Humid Periods, dust export was reduced but may not have completely ceased. The loading patterns of two fluvial end members show a strong relationship with the Northern Hemisphere insolation, and all fluvial end members document enhanced input during the African Humid Periods. The sapropel end member most likely reflects the fixation of redox-sensitive elements within the anoxic sapropel layers. Our results exemplify that end-member modelling is a valuable tool for interpreting extensive and multidisciplinary datasets.
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Identifying early modern human ecological niche expansions and associated cultural dynamics in the South African Middle Stone Age. Proc Natl Acad Sci U S A 2017; 114:7869-7876. [PMID: 28739910 DOI: 10.1073/pnas.1620752114] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The archaeological record shows that typically human cultural traits emerged at different times, in different parts of the world, and among different hominin taxa. This pattern suggests that their emergence is the outcome of complex and nonlinear evolutionary trajectories, influenced by environmental, demographic, and social factors, that need to be understood and traced at regional scales. The application of predictive algorithms using archaeological and paleoenvironmental data allows one to estimate the ecological niches occupied by past human populations and identify niche changes through time, thus providing the possibility of investigating relationships between cultural innovations and possible niche shifts. By using such methods to examine two key southern Africa archaeological cultures, the Still Bay [76-71 thousand years before present (ka)] and the Howiesons Poort (HP; 66-59 ka), we identify a niche shift characterized by a significant expansion in the breadth of the HP ecological niche. This expansion is coincident with aridification occurring across Marine Isotope Stage 4 (ca. 72-60 ka) and especially pronounced at 60 ka. We argue that this niche shift was made possible by the development of a flexible technological system, reliant on composite tools and cultural transmission strategies based more on "product copying" rather than "process copying." These results counter the one niche/one human taxon equation. They indicate that what makes our cultures, and probably the cultures of other members of our lineage, unique is their flexibility and ability to produce innovations that allow a population to shift its ecological niche.
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18
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Houldcroft CJ, Ramond JB, Rifkin RF, Underdown SJ. Migrating microbes: what pathogens can tell us about population movements and human evolution. Ann Hum Biol 2017; 44:397-407. [PMID: 28511559 DOI: 10.1080/03014460.2017.1325515] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND The biology of human migration can be observed from the co-evolutionary relationship with infectious diseases. While many pathogens are brief, unpleasant visitors to human bodies, others have the ability to become life-long human passengers. The story of a pathogen's genetic code may, therefore, provide insight into the history of its human host. The evolution and distribution of disease in Africa is of particular interest, because of the deep history of human evolution in Africa, the presence of a variety of non-human primates, and tropical reservoirs of emerging infectious diseases. METHODS This study explores which pathogens leave traces in the archaeological record, and whether there are realistic prospects that these pathogens can be recovered from sub-Saharan African archaeological contexts. RESULTS Three stories are then presented of germs on a journey. The first is the story of HIV's spread on the back of colonialism and the railway networks over the last 150 years. The second involves the spread of Schistosoma mansoni, a parasite which shares its history with the trans-Atlantic slave trade and the origins of fresh-water fishing. Finally, we discuss the tantalising hints of hominin migration and interaction found in the genome of human herpes simplex virus 2. CONCLUSIONS Evidence from modern African pathogen genomes can provide data on human behaviour and migration in deep time and contribute to the improvement of human quality-of-life and longevity.
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Affiliation(s)
- Charlotte J Houldcroft
- a Department of Archaeology and Anthropology, Division of Biological Anthropology , University of Cambridge , Cambridge , UK.,b McDonald Institute of Archaeological Research, University of Cambridge , Cambridge , UK
| | - Jean-Baptiste Ramond
- c Department of Genetics , Centre for Microbial Ecology and Genomics, Genomic Research Institute, University of Pretoria , Hatfield , South Africa
| | - Riaan F Rifkin
- c Department of Genetics , Centre for Microbial Ecology and Genomics, Genomic Research Institute, University of Pretoria , Hatfield , South Africa
| | - Simon J Underdown
- d Department of Anthropology & Geography, Human Origins and Palaeoenvironmental Research Group (HOPE) , Oxford Brookes University , Oxford , UK.,e Leverhulme Centre for Human Evolutionary Studies , Henry Wellcome Building , Cambridge , UK
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19
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Vahia MN, Yadav N, Ladiwala U, Mathur D. A diffusion based study of population dynamics: Prehistoric migrations into South Asia. PLoS One 2017; 12:e0176985. [PMID: 28493906 PMCID: PMC5426639 DOI: 10.1371/journal.pone.0176985] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Accepted: 04/20/2017] [Indexed: 01/04/2023] Open
Abstract
A diffusion equation has been used to study migration of early humans into the South Asian subcontinent. The diffusion equation is tempered by a set of parameters that account for geographical features like proximity to water resources, altitude, and flatness of land. The ensuing diffusion of populations is followed in time-dependent computer simulations carried out over a period of 10,000 YBP. The geographical parameters are determined from readily-available satellite data. The results of our computer simulations are compared to recent genetic data so as to better correlate the migratory patterns of various populations; they suggest that the initial populations started to coalesce around 4,000 YBP before the commencement of a period of relative geographical isolation of each population group. The period during which coalescence of populations occurred appears consistent with the established timeline associated with the Harappan civilization and also, with genetic admixing that recent genetic mapping data reveal. Our results may contribute to providing a timeline for the movement of prehistoric people. Most significantly, our results appear to suggest that the Ancestral Austro-Asiatic population entered the subcontinent through an easterly direction, potentially resolving a hitherto-contentious issue.
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Affiliation(s)
- Mayank N. Vahia
- Tata Institute of Fundamental Research, Mumbai, India
- * E-mail:
| | - Nisha Yadav
- Tata Institute of Fundamental Research, Mumbai, India
| | - Uma Ladiwala
- Tata Institute of Fundamental Research, Mumbai, India
| | - Deepak Mathur
- Tata Institute of Fundamental Research, Mumbai, India
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20
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African genomes illuminate the early history and transition to selfing in Arabidopsis thaliana. Proc Natl Acad Sci U S A 2017; 114:5213-5218. [PMID: 28473417 DOI: 10.1073/pnas.1616736114] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Over the past 20 y, many studies have examined the history of the plant ecological and molecular model, Arabidopsis thaliana, in Europe and North America. Although these studies informed us about the recent history of the species, the early history has remained elusive. In a large-scale genomic analysis of African A. thaliana, we sequenced the genomes of 78 modern and herbarium samples from Africa and analyzed these together with over 1,000 previously sequenced Eurasian samples. In striking contrast to expectations, we find that all African individuals sampled are native to this continent, including those from sub-Saharan Africa. Moreover, we show that Africa harbors the greatest variation and represents the deepest history in the A. thaliana lineage. Our results also reveal evidence that selfing, a major defining characteristic of the species, evolved in a single geographic region, best represented today within Africa. Demographic inference supports a model in which the ancestral A. thaliana population began to split by 120-90 kya, during the last interglacial and Abbassia pluvial, and Eurasian populations subsequently separated from one another at around 40 kya. This bears striking similarities to the patterns observed for diverse species, including humans, implying a key role for climatic events during interglacial and pluvial periods in shaping the histories and current distributions of a wide range of species.
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21
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The chronostratigraphy of the Haua Fteah cave (Cyrenaica, northeast Libya) — Optical dating of early human occupation during Marine Isotope Stages 4, 5 and 6. J Hum Evol 2017; 105:69-88. [DOI: 10.1016/j.jhevol.2017.01.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 01/11/2017] [Accepted: 01/24/2017] [Indexed: 11/20/2022]
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22
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Mapping Palaeohydrography in Deserts: Contribution from Space-Borne Imaging Radar. WATER 2017. [DOI: 10.3390/w9030194] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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23
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Ehrmann W, Schmiedl G, Beuscher S, Krüger S. Intensity of African Humid Periods Estimated from Saharan Dust Fluxes. PLoS One 2017; 12:e0170989. [PMID: 28129378 PMCID: PMC5271358 DOI: 10.1371/journal.pone.0170989] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 01/13/2017] [Indexed: 11/19/2022] Open
Abstract
North Africa experienced dramatic changes in hydrology and vegetation during the late Quaternary driven by insolation-induced shifts of the tropical rain belt and further modulated by millennial-scale droughts and vegetation-climate feedbacks. While most past proxy and modelling studies concentrated on the temporal and spatial dynamics of the last African humid period, little is known about the intensities and characteristics of pre-Holocene humid periods. Here we present a high-resolution record of fine-grained eastern Saharan dust from the Eastern Mediterranean Sea spanning the last 180 kyr, which is based on the clay mineral composition of the marine sediments, especially the kaolinite/chlorite ratio. Minimum aeolian kaolinite transport occurred during the African Humid Periods because kaolinite deflation was hampered by increased humidity and vegetation cover. Instead, kaolinite weathering from kaolinite-bearing Cenozoic rocks was stored in lake basins, river beds and soils during these periods. During the subsequent dry phases, fine-grained dust was mobilised from the desiccated lakes, rivers and soils resulting in maximum aeolian uptake and transport of kaolinite. The kaolinite transport decreased again when these sediment sources exhausted. We conclude that the amount of clay-sized dust blown out of the Sahara into the Eastern Mediterranean Sea is proportional to the intensity of the kaolinite weathering and accumulation in soils and lake sediments, and thus to the strength of the preceding humid period. These humid periods provided the windows for the migration of modern humans out of Africa, as postulated previously. The strongest humid period occurred during the Eemian and was followed by two weaker phases centred at ca. 100 ka and ca. 80 ka.
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Affiliation(s)
- Werner Ehrmann
- Institut für Geophysik und Geologie, Universität Leipzig, Talstraße 35, Leipzig, Germany
- * E-mail:
| | - Gerhard Schmiedl
- Centrum für Erdsystemforschung und Nachhaltigkeit, Universität Hamburg, Bundesstraße 55, Hamburg, Germany
| | - Sarah Beuscher
- Institut für Geophysik und Geologie, Universität Leipzig, Talstraße 35, Leipzig, Germany
| | - Stefan Krüger
- Institut für Geophysik und Geologie, Universität Leipzig, Talstraße 35, Leipzig, Germany
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Timing and causes of North African wet phases during the last glacial period and implications for modern human migration. Sci Rep 2016; 6:36367. [PMID: 27808237 PMCID: PMC5093410 DOI: 10.1038/srep36367] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 09/29/2016] [Indexed: 11/08/2022] Open
Abstract
We present the first speleothem-derived central North Africa rainfall record for the last glacial period. The record reveals three main wet periods at 65-61 ka, 52.5-50.5 ka and 37.5-33 ka that lead obliquity maxima and precession minima. We find additional minor wet episodes that are synchronous with Greenland interstadials. Our results demonstrate that sub-tropical hydrology is forced by both orbital cyclicity and North Atlantic moisture sources. The record shows that after the end of a Saharan wet phase around 70 ka ago, North Africa continued to intermittently receive substantially more rainfall than today, resulting in favourable environmental conditions for modern human expansion. The encounter and subsequent mixture of Neanderthals and modern humans – which, on genetic evidence, is considered to have occurred between 60 and 50 ka – occurred synchronously with the wet phase between 52.5 and 50.5 ka. Based on genetic evidence the dispersal of modern humans into Eurasia started less than 55 ka ago. This may have been initiated by dry conditions that prevailed in North Africa after 50.5 ka. The timing of a migration reversal of modern humans from Eurasia into North Africa is suggested to be coincident with the wet period between 37.5 and 33 ka.
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26
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Cherni L, Pakstis AJ, Boussetta S, Elkamel S, Frigi S, Khodjet-El-Khil H, Barton A, Haigh E, Speed WC, Ben Ammar Elgaaied A, Kidd JR, Kidd KK. Genetic variation in Tunisia in the context of human diversity worldwide. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 161:62-71. [PMID: 27192181 PMCID: PMC5084816 DOI: 10.1002/ajpa.23008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 04/22/2016] [Indexed: 11/09/2022]
Abstract
OBJECTIVES North Africa has a complex demographic history of migrations from within Africa, Europe, and the Middle East. However, population genetic studies, especially for autosomal genetic markers, are few relative to other world regions. We examined autosomal markers for eight Tunisian and Libyan populations in order to place them in a global context. MATERIALS AND METHODS Data were collected by TaqMan on 399 autosomal single nucleotide polymorphisms on 331 individuals from Tunisia and Libya. These data were combined with data on the same SNPs previously typed on 2585 individuals from 57 populations from around the world. Where meaningful, close by SNPs were combined into multiallelic haplotypes. Data were evaluated by clustering, principal components, and population tree analyses. For a subset of 102 SNPs, data from the literature on seven additional North African populations were included in analyses. RESULTS Average heterozygosity of the North African populations is high relative to our global samples, consistent with a complex demographic history. The Tunisian and Libyan samples form a discrete cluster in the global and regional views and can be separated from sub-Sahara, Middle East, and Europe. Within Tunisia the Nebeur and Smar are outlier groups. Across North Africa, pervasive East-West geographical patterns were not found. DISCUSSION Known historical migrations and invasions did not displace or homogenize the genetic variation in the region but rather enriched it. Even a small region like Tunisia contains considerable genetic diversity. Future studies across North Africa have the potential to increase our understanding of the historical demographic factors influencing the region. Am J Phys Anthropol 161:62-71, 2016. © 2016 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Lotfi Cherni
- Laboratory of Genetics, Immunology and Human Pathology, Science Faculty of Tunis, University of Tunis El Manar, 2092, Tunis, Tunisia.,High Institute of Biotechnology, University of Monastir, Monastir, 5000, Tunisia
| | - Andrew J Pakstis
- Department of Genetics, Yale University School of Medicine, New Haven, CT, 06520
| | - Sami Boussetta
- Laboratory of Genetics, Immunology and Human Pathology, Science Faculty of Tunis, University of Tunis El Manar, 2092, Tunis, Tunisia
| | - Sarra Elkamel
- Laboratory of Genetics, Immunology and Human Pathology, Science Faculty of Tunis, University of Tunis El Manar, 2092, Tunis, Tunisia
| | - Sabeh Frigi
- Laboratory of Genetics, Immunology and Human Pathology, Science Faculty of Tunis, University of Tunis El Manar, 2092, Tunis, Tunisia
| | - Houssein Khodjet-El-Khil
- Laboratory of Genetics, Immunology and Human Pathology, Science Faculty of Tunis, University of Tunis El Manar, 2092, Tunis, Tunisia
| | - Alison Barton
- Department of Genetics, Yale University School of Medicine, New Haven, CT, 06520
| | - Eva Haigh
- Department of Genetics, Yale University School of Medicine, New Haven, CT, 06520
| | - William C Speed
- Department of Genetics, Yale University School of Medicine, New Haven, CT, 06520
| | - Amel Ben Ammar Elgaaied
- Laboratory of Genetics, Immunology and Human Pathology, Science Faculty of Tunis, University of Tunis El Manar, 2092, Tunis, Tunisia
| | - Judith R Kidd
- Department of Genetics, Yale University School of Medicine, New Haven, CT, 06520
| | - Kenneth K Kidd
- Department of Genetics, Yale University School of Medicine, New Haven, CT, 06520
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Jacquet S, Garros C, Lombaert E, Walton C, Restrepo J, Allene X, Baldet T, Cetre-Sossah C, Chaskopoulou A, Delecolle JC, Desvars A, Djerbal M, Fall M, Gardes L, de Garine-Wichatitsky M, Goffredo M, Gottlieb Y, Gueye Fall A, Kasina M, Labuschagne K, Lhor Y, Lucientes J, Martin T, Mathieu B, Miranda M, Pages N, Pereira da Fonseca I, Ramilo DW, Segard A, Setier-Rio ML, Stachurski F, Tabbabi A, Talla Seck M, Venter G, Zimba M, Balenghien T, Guis H, Chevillon C, Bouyer J, Huber K. Colonization of the Mediterranean basin by the vector biting midge speciesCulicoides imicola: an old story. Mol Ecol 2015; 24:5707-25. [DOI: 10.1111/mec.13422] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 10/06/2015] [Accepted: 10/09/2015] [Indexed: 11/27/2022]
Affiliation(s)
- S. Jacquet
- CIRAD UMR15 CMAEE; 34398 Montpellier France
- INRA UMR1309 CMAEE; 34398 Montpellier France
- CNRS; UMR 5290 Maladies Infectieuses & Vecteurs-Ecologie, Génétique, Ecologie, Contrôle (MIVEGEC); Université de Montpellier; Montpellier France
- IRD; UR 224 MIVEGEC; BP 64501, Agropolis 34394 Montpellier Cedex 5 France
| | - C. Garros
- CIRAD UMR15 CMAEE; 34398 Montpellier France
- INRA UMR1309 CMAEE; 34398 Montpellier France
| | - E. Lombaert
- INRA; UMR1355; Institut Sophia Agrobiotech; 06903 Sophia Antipolis France
| | - C. Walton
- Computational and Evolutionary Biology; Faculty of Life Sciences; University of Manchester; Manchester UK
| | - J. Restrepo
- CIRAD UMR15 CMAEE; 34398 Montpellier France
- INRA UMR1309 CMAEE; 34398 Montpellier France
| | - X. Allene
- CIRAD UMR15 CMAEE; 34398 Montpellier France
- INRA UMR1309 CMAEE; 34398 Montpellier France
| | - T. Baldet
- CIRAD UMR15 CMAEE; 34398 Montpellier France
- INRA UMR1309 CMAEE; 34398 Montpellier France
| | - C. Cetre-Sossah
- CIRAD UMR15 CMAEE; 34398 Montpellier France
- INRA UMR1309 CMAEE; 34398 Montpellier France
- Plateforme de recherche CYROI; CRVOI; Sainte Clotilde La Réunion France
| | - A. Chaskopoulou
- USDA-ARS European Biological Control Laboratory; 54623 Thessaloniki Greece
| | - J.-C. Delecolle
- Medicine Faculty; Institute of Parasitology and Tropical Pathology (IPPTS); EA7292 67000 Strasbourg France
| | - A. Desvars
- Department of Clinical Microbiology; Umea University; Umea Sweden
| | - M. Djerbal
- Regional Veterinary Laboratory of Draa-Ben-Kheda; Tizi-Ouzou Algeria
| | - M. Fall
- ISRA-LNERV; BP 2057 Dakar Senegal
| | - L. Gardes
- CIRAD UMR15 CMAEE; 34398 Montpellier France
- INRA UMR1309 CMAEE; 34398 Montpellier France
| | - M. de Garine-Wichatitsky
- Cirad; UPR AGIRs, RP-PCP; Harare Zimbabwe
- Cirad; UPR AGIRs; Montpellier France
- Department of Biological Sciences, Entomology; University of Zimbabwe; PO Box MP 167 Mount Pleasant Harare Zimbabwe
| | - M. Goffredo
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise ‘G. Caporale’; 64100 Teramo Italy
| | - Y. Gottlieb
- Koret School of Veterinary Medicine; The Robert H. Smith Faculty of Agriculture, Food and Environment; The Hebrew University of Jerusalem; Rehovot Israel
| | | | - M. Kasina
- Kenya Agricultural and Livestock Research Organization Sericulture; PO Box 7816 Code 01000 Thika Kenya
| | - K. Labuschagne
- Agricultural Research Council-Onderstepoort Veterinary Institute, Parasites, Vectors and Vector-borne Diseases; Onderstepoort 0110 South Africa
| | - Y. Lhor
- Office National de Sécurité Sanitaire des produits Alimentaires (ONSSA); Rabat Morocco
| | - J. Lucientes
- Departamento de Patología Animal; Facultad de Veterinaria; Universidad de Zaragoza; Zaragoza Spain
| | - T. Martin
- UR Hortsys; Cirad; Montpellier France
- Plant Health Department; ICIPE; Nairobi Kenya
| | - B. Mathieu
- Medicine Faculty; Institute of Parasitology and Tropical Pathology (IPPTS); EA7292 67000 Strasbourg France
- EID Méditerranée; 34184 Montpellier France
| | - M. Miranda
- Laboratory of Zoology; University of Balearics (UIB); Palma de Mallorca Spain
| | - N. Pages
- INRA UMR1309 CMAEE; 34398 Montpellier France
- Centre de Recerca en Sanitat Animal (CReSA); UAB-IRTA; Campus de la Universitat Autònoma de Barcelona 08193 Bellaterra (Cerdanyola del Vallès) Spain
- CIRAD; UMR CMAEE; 97170 Petit Bourg Guadeloupe France
| | | | - D. W. Ramilo
- Faculdade de Medicina Veterinária; CIISA; ULisboa; 1300-477 Lisboa Portugal
| | - A. Segard
- CNRS; UMR 5175 CEFE; Université de Montpellier; Montpellier France
- EPHE Campus CNRS; 1919 route de Mende 34293 Montpellier Cedex 5 France
| | | | - F. Stachurski
- CIRAD UMR15 CMAEE; 34398 Montpellier France
- INRA UMR1309 CMAEE; 34398 Montpellier France
| | - A. Tabbabi
- Lab of Medical Parasitology, Biotechnologies & Biomolecules (LR 11 IPT 06); Pasteur Institute of Tunis; Tunis Tunisia
| | | | - G. Venter
- Agricultural Research Council-Onderstepoort Veterinary Institute, Parasites, Vectors and Vector-borne Diseases; Onderstepoort 0110 South Africa
| | - M. Zimba
- Department of Biological Sciences, Entomology; University of Zimbabwe; PO Box MP 167 Mount Pleasant Harare Zimbabwe
| | - T. Balenghien
- CIRAD UMR15 CMAEE; 34398 Montpellier France
- INRA UMR1309 CMAEE; 34398 Montpellier France
| | - H. Guis
- CIRAD UMR15 CMAEE; 34398 Montpellier France
- INRA UMR1309 CMAEE; 34398 Montpellier France
| | - C. Chevillon
- CNRS; UMR 5290 Maladies Infectieuses & Vecteurs-Ecologie, Génétique, Ecologie, Contrôle (MIVEGEC); Université de Montpellier; Montpellier France
- IRD; UR 224 MIVEGEC; BP 64501, Agropolis 34394 Montpellier Cedex 5 France
| | - J. Bouyer
- CIRAD UMR15 CMAEE; 34398 Montpellier France
- INRA UMR1309 CMAEE; 34398 Montpellier France
- ISRA-LNERV; BP 2057 Dakar Senegal
| | - K. Huber
- CIRAD UMR15 CMAEE; 34398 Montpellier France
- INRA UMR1309 CMAEE; 34398 Montpellier France
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Evolution and dispersal of the genus Homo: A landscape approach. J Hum Evol 2015; 87:48-65. [PMID: 26235482 DOI: 10.1016/j.jhevol.2015.07.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 07/05/2015] [Accepted: 07/09/2015] [Indexed: 02/07/2023]
Abstract
The notion of the physical landscape as an arena of ecological interaction and human evolution is a powerful one, but its implementation at larger geographical and temporal scales is hampered by the challenges of reconstructing physical landscape settings in the geologically active regions where the earliest evidence is concentrated. We argue that the inherently dynamic nature of these unstable landscapes has made them important agents of biological change, creating complex topographies capable of selecting for, stimulating, obstructing or accelerating the latent and emerging properties of the human evolutionary trajectory. We use this approach, drawing on the concepts and methods of active tectonics, to develop a new perspective on the origins and dispersal of the Homo genus. We show how complex topography provides an easy evolutionary pathway to full terrestrialisation in the African context, and would have further equipped members of the genus Homo with a suite of adaptive characteristics that facilitated wide-ranging dispersal across ecological and climatic boundaries into Europe and Asia by following pathways of complex topography. We compare this hypothesis with alternative explanations for hominin dispersal, and evaluate it by mapping the distribution of topographic features at varying scales, and comparing the distribution of early Homo sites with the resulting maps and with other environmental variables.
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Fregel R, Cabrera V, Larruga JM, Abu-Amero KK, González AM. Carriers of Mitochondrial DNA Macrohaplogroup N Lineages Reached Australia around 50,000 Years Ago following a Northern Asian Route. PLoS One 2015; 10:e0129839. [PMID: 26053380 PMCID: PMC4460043 DOI: 10.1371/journal.pone.0129839] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 05/13/2015] [Indexed: 01/17/2023] Open
Abstract
Background The modern human colonization of Eurasia and Australia is mostly explained by a single-out-of-Africa exit following a southern coastal route throughout Arabia and India. However, dispersal across the Levant would better explain the introgression with Neanderthals, and more than one exit would fit better with the different ancient genomic components discovered in indigenous Australians and in ancient Europeans. The existence of an additional Northern route used by modern humans to reach Australia was previously deduced from the phylogeography of mtDNA macrohaplogroup N. Here, we present new mtDNA data and new multidisciplinary information that add more support to this northern route. Methods MtDNA hypervariable segments and haplogroup diagnostic coding positions were analyzed in 2,278 Saudi Arabs, from which 1,725 are new samples. Besides, we used 623 published mtDNA genomes belonging to macrohaplogroup N, but not R, to build updated phylogenetic trees to calculate their coalescence ages, and more than 70,000 partial mtDNA sequences were screened to establish their respective geographic ranges. Results The Saudi mtDNA profile confirms the absence of autochthonous mtDNA lineages in Arabia with coalescence ages deep enough to support population continuity in the region since the out-of-Africa episode. In contrast to Australia, where N(xR) haplogroups are found in high frequency and with deep coalescence ages, there are not autochthonous N(xR) lineages in India nor N(xR) branches with coalescence ages as deep as those found in Australia. These patterns are at odds with the supposition that Australian colonizers harboring N(xR) lineages used a route involving India as a stage. The most ancient N(xR) lineages in Eurasia are found in China, and inconsistently with the coastal route, N(xR) haplogroups with the southernmost geographical range have all more recent radiations than the Australians. Conclusions Apart from a single migration event via a southern route, phylogeny and phylogeography of N(xR) lineages support that people carrying mtDNA N lineages could have reach Australia following a northern route through Asia. Data from other disciplines also support this scenario.
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Affiliation(s)
- Rosa Fregel
- Departamento de Genética, Facultad de Biología, Universidad de La Laguna, La Laguna, Tenerife, Spain
- * E-mail:
| | - Vicente Cabrera
- Departamento de Genética, Facultad de Biología, Universidad de La Laguna, La Laguna, Tenerife, Spain
| | - Jose M. Larruga
- Departamento de Genética, Facultad de Biología, Universidad de La Laguna, La Laguna, Tenerife, Spain
| | - Khaled K. Abu-Amero
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Ana M. González
- Departamento de Genética, Facultad de Biología, Universidad de La Laguna, La Laguna, Tenerife, Spain
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Pokorny L, Riina R, Mairal M, Meseguer AS, Culshaw V, Cendoya J, Serrano M, Carbajal R, Ortiz S, Heuertz M, Sanmartín I. Living on the edge: timing of Rand Flora disjunctions congruent with ongoing aridification in Africa. Front Genet 2015; 6:154. [PMID: 25983742 PMCID: PMC4416453 DOI: 10.3389/fgene.2015.00154] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 04/05/2015] [Indexed: 01/16/2023] Open
Abstract
The Rand Flora is a well-known floristic pattern in which unrelated plant lineages show similar disjunct distributions in the continental margins of Africa and adjacent islands—Macaronesia-northwest Africa, Horn of Africa-Southern Arabia, Eastern Africa, and Southern Africa. These lineages are now separated by environmental barriers such as the arid regions of the Sahara and Kalahari Deserts or the tropical lowlands of Central Africa. Alternative explanations for the Rand Flora pattern range from vicariance and climate-driven extinction of a widespread pan-African flora to independent dispersal events and speciation in situ. To provide a temporal framework for this pattern, we used published data from nuclear and chloroplast DNA to estimate the age of disjunction of 17 lineages that span 12 families and nine orders of angiosperms. We further used these estimates to infer diversification rates for Rand Flora disjunct clades in relation to their higher-level encompassing lineages. Our results indicate that most disjunctions fall within the Miocene and Pliocene periods, coinciding with the onset of a major aridification trend, still ongoing, in Africa. Age of disjunctions seemed to be related to the climatic affinities of each Rand Flora lineage, with sub-humid taxa dated earlier (e.g., Sideroxylon) and those with more xeric affinities (e.g., Campylanthus) diverging later. We did not find support for significant decreases in diversification rates in most groups, with the exception of older subtropical lineages (e.g., Sideroxylon, Hypericum, or Canarina), but some lineages (e.g., Cicer, Campylanthus) showed a long temporal gap between stem and crown ages, suggestive of extinction. In all, the Rand Flora pattern seems to fit the definition of biogeographic pseudocongruence, with the pattern arising at different times in response to the increasing aridity of the African continent, with interspersed periods of humidity allowing range expansions.
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Affiliation(s)
| | | | | | - Andrea S Meseguer
- INRA, UMR 1062, Centre de Biologie pour la Gestion des Populations (INRA, IRD, CIRAD, Montpellier SupAgro) Montferrier-sur-Lez, France
| | | | - Jon Cendoya
- Real Jardín Botánico (RJB-CSIC) Madrid, Spain
| | - Miguel Serrano
- Department of Botany, Pharmacy School, University of Santiago de Compostela Santiago de Compostela, Spain
| | - Rodrigo Carbajal
- Department of Botany, Pharmacy School, University of Santiago de Compostela Santiago de Compostela, Spain
| | - Santiago Ortiz
- Department of Botany, Pharmacy School, University of Santiago de Compostela Santiago de Compostela, Spain
| | - Myriam Heuertz
- Forest Research Centre (INIA-CIFOR) Madrid, Spain ; INRA, BIOGECO, UMR 1202 Cestas, France ; University of Bordeaux, BIOGECO, UMR 1202 Talence, France
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Complete mitochondrial DNA sequence of the endangered giant sable antelope (Hippotragus niger variani): Insights into conservation and taxonomy. Mol Phylogenet Evol 2015; 83:242-9. [DOI: 10.1016/j.ympev.2014.12.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 12/04/2014] [Accepted: 12/06/2014] [Indexed: 12/21/2022]
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Were Upper Pleistocene human/non-human predator occupations at the Témara caves (El Harhoura 2 and El Mnasra, Morocco) influenced by climate change? J Hum Evol 2014; 78:122-43. [PMID: 25281232 DOI: 10.1016/j.jhevol.2014.08.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 08/14/2014] [Accepted: 08/14/2014] [Indexed: 11/23/2022]
Abstract
The influence of climate change on human settlements in coastal areas is a central question for archaeologists. This paper addresses this issue by focusing on the Témara region in Morocco. The study area was selected for two main reasons. First, it contains numerous caves with Upper Pleistocene deposits, which have yielded remains of anatomically modern humans in association with Aterian and Iberomaurusian artifacts. Second, these caves are currently located on the shore, thus this region is particularly sensitive to major climate change and sea level fluctuations. Diachronic taphonomic study of faunal remains from two sites in the region, El Harhoura 2 and El Mnasra caves, shows alternating human/non-human predator occupations. The lower layers of El Mnasra Cave dating to Oxygen Isotope Stage (OIS) 5 have yielded diverse ungulate remains with significant anthropogenic impact marks, together with numerous mollusk shells, Nassarius shell beads, hearths, lithics, some bone tools and used pigments. Faunal remains from the upper layers dating to OIS 4, 3 and 2 of El Harhoura 2 and El Mnasra caves, largely dominated by gazelles, provide evidence of carnivore activities, such as tooth marks, numerous semi-digested bones and coprolites alongside some anthropogenic signatures (cut marks and burnt bones). Non-human predators appear to be the main agents responsible for faunal modifications and accumulations. The 'non-intensive' nature of human occupation is confirmed by analyses of the lithic industry at El Harhoura 2. The 'intensive' human occupations date to OIS 5 and could have taken place during wet periods in connection with high sea levels, which allowed the exploitation of shellfish in this area. 'Non-intensive' human occupations generally correspond to arid periods and lower sea levels, during which the Témara area was further inland and may have been less attractive to humans.
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Barnett R, Yamaguchi N, Shapiro B, Ho SYW, Barnes I, Sabin R, Werdelin L, Cuisin J, Larson G. Revealing the maternal demographic history of Panthera leo using ancient DNA and a spatially explicit genealogical analysis. BMC Evol Biol 2014; 14:70. [PMID: 24690312 PMCID: PMC3997813 DOI: 10.1186/1471-2148-14-70] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 03/13/2014] [Indexed: 11/15/2022] Open
Abstract
Background Understanding the demographic history of a population is critical to conservation and to our broader understanding of evolutionary processes. For many tropical large mammals, however, this aim is confounded by the absence of fossil material and by the misleading signal obtained from genetic data of recently fragmented and isolated populations. This is particularly true for the lion which as a consequence of millennia of human persecution, has large gaps in its natural distribution and several recently extinct populations. Results We sequenced mitochondrial DNA from museum-preserved individuals, including the extinct Barbary lion (Panthera leo leo) and Iranian lion (P. l. persica), as well as lions from West and Central Africa. We added these to a broader sample of lion sequences, resulting in a data set spanning the historical range of lions. Our Bayesian phylogeographical analyses provide evidence for highly supported, reciprocally monophyletic lion clades. Using a molecular clock, we estimated that recent lion lineages began to diverge in the Late Pleistocene. Expanding equatorial rainforest probably separated lions in South and East Africa from other populations. West African lions then expanded into Central Africa during periods of rainforest contraction. Lastly, we found evidence of two separate incursions into Asia from North Africa, first into India and later into the Middle East. Conclusions We have identified deep, well-supported splits within the mitochondrial phylogeny of African lions, arguing for recognition of some regional populations as worthy of independent conservation. More morphological and nuclear DNA data are now needed to test these subdivisions.
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Affiliation(s)
- Ross Barnett
- Durham Evolution and Ancient DNA, Department of Archaeology, Durham University, Durham DH1 3LE, UK.
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Douka K, Jacobs Z, Lane C, Grün R, Farr L, Hunt C, Inglis RH, Reynolds T, Albert P, Aubert M, Cullen V, Hill E, Kinsley L, Roberts RG, Tomlinson EL, Wulf S, Barker G. The chronostratigraphy of the Haua Fteah cave (Cyrenaica, northeast Libya). J Hum Evol 2013; 66:39-63. [PMID: 24331954 DOI: 10.1016/j.jhevol.2013.10.001] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 10/25/2013] [Accepted: 10/25/2013] [Indexed: 11/16/2022]
Abstract
The 1950s excavations by Charles McBurney in the Haua Fteah, a large karstic cave on the coast of northeast Libya, revealed a deep sequence of human occupation. Most subsequent research on North African prehistory refers to his discoveries and interpretations, but the chronology of its archaeological and geological sequences has been based on very early age determinations. This paper reports on the initial results of a comprehensive multi-method dating program undertaken as part of new work at the site, involving radiocarbon dating of charcoal, land snails and marine shell, cryptotephra investigations, optically stimulated luminescence (OSL) dating of sediments, and electron spin resonance (ESR) dating of tooth enamel. The dating samples were collected from the newly exposed and cleaned faces of the upper 7.5 m of the ∼14.0 m-deep McBurney trench, which contain six of the seven major cultural phases that he identified. Despite problems of sediment transport and reworking, using a Bayesian statistical model the new dating program establishes a robust framework for the five major lithostratigraphic units identified in the stratigraphic succession, and for the major cultural units. The age of two anatomically modern human mandibles found by McBurney in Layer XXXIII near the base of his Levalloiso-Mousterian phase can now be estimated to between 73 and 65 ka (thousands of years ago) at the 95.4% confidence level, within Marine Isotope Stage (MIS) 4. McBurney's Layer XXV, associated with Upper Palaeolithic Dabban blade industries, has a clear stratigraphic relationship with Campanian Ignimbrite tephra. Microlithic Oranian technologies developed following the climax of the Last Glacial Maximum and the more microlithic Capsian in the Younger Dryas. Neolithic pottery and perhaps domestic livestock were used in the cave from the mid Holocene but there is no certain evidence for plant cultivation until the Graeco-Roman period.
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Affiliation(s)
- Katerina Douka
- Research Laboratory for Archaeology and the History of Art, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford OX1 3QY, UK.
| | - Zenobia Jacobs
- Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW 2522, Australia.
| | - Christine Lane
- Research Laboratory for Archaeology and the History of Art, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford OX1 3QY, UK.
| | - Rainer Grün
- Research School of Earth Sciences, Australian National University, Canberra 0200, Australia.
| | - Lucy Farr
- McDonald Institute for Archaeological Research, University of Cambridge, Cambridge CB2 3ER, UK.
| | - Chris Hunt
- School of Geography, Archaeology and Palaeoecology, Queen's University Belfast, Belfast BT7 1NN, Ireland.
| | - Robyn H Inglis
- Department of Archaeology, University of York, King's Manor, York YO1 7EP, UK.
| | - Tim Reynolds
- Department of History, Classics and Archaeology, Birkbeck College, University of London, 26 Russell Square, London WC1B 5DQ, UK.
| | - Paul Albert
- Department of Earth Sciences, Royal Holloway University of London, Egham TW20 0EX, UK.
| | - Maxime Aubert
- Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW 2522, Australia.
| | - Victoria Cullen
- Research Laboratory for Archaeology and the History of Art, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford OX1 3QY, UK.
| | - Evan Hill
- School of Geography, Archaeology and Palaeoecology, Queen's University Belfast, Belfast BT7 1NN, Ireland.
| | - Leslie Kinsley
- Research School of Earth Sciences, Australian National University, Canberra 0200, Australia.
| | - Richard G Roberts
- Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW 2522, Australia.
| | - Emma L Tomlinson
- Department of Geology, Trinity College Dublin, Dublin 2, Ireland; Department of Earth Sciences, Royal Holloway University of London, Egham TW20 0EX, UK.
| | - Sabine Wulf
- GFZ German Research Centre for Geosciences, Section 5.2 - Climate Dynamics and Landscape Evolution, Telegrafenberg, D-14473 Potsdam, Germany.
| | - Graeme Barker
- McDonald Institute for Archaeological Research, University of Cambridge, Cambridge CB2 3ER, UK.
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Rohling EJ, Grant KM, Roberts AP, Larrasoaña JC. Paleoclimate Variability in the Mediterranean and Red Sea Regions during the Last 500,000 Years. CURRENT ANTHROPOLOGY 2013. [DOI: 10.1086/673882] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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d’Errico F, Banks WE. Identifying Mechanisms behind Middle Paleolithic and Middle Stone Age Cultural Trajectories. CURRENT ANTHROPOLOGY 2013. [DOI: 10.1086/673388] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Dynamics of green Sahara periods and their role in hominin evolution. PLoS One 2013; 8:e76514. [PMID: 24146882 PMCID: PMC3797788 DOI: 10.1371/journal.pone.0076514] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 08/28/2013] [Indexed: 11/21/2022] Open
Abstract
Astronomically forced insolation changes have driven monsoon dynamics and recurrent humid episodes in North Africa, resulting in green Sahara Periods (GSPs) with savannah expansion throughout most of the desert. Despite their potential for expanding the area of prime hominin habitats and favouring out-of-Africa dispersals, GSPs have not been incorporated into the narrative of hominin evolution due to poor knowledge of their timing, dynamics and landscape composition at evolutionary timescales. We present a compilation of continental and marine paleoenvironmental records from within and around North Africa, which enables identification of over 230 GSPs within the last 8 million years. By combining the main climatological determinants of woody cover in tropical Africa with paleoenvironmental and paleoclimatic data for representative (Holocene and Eemian) GSPs, we estimate precipitation regimes and habitat distributions during GSPs. Their chronology is consistent with the ages of Saharan archeological and fossil hominin sites. Each GSP took 2–3 kyr to develop, peaked over 4–8 kyr, biogeographically connected the African tropics to African and Eurasian mid latitudes, and ended within 2–3 kyr, which resulted in rapid habitat fragmentation. We argue that the well-dated succession of GSPs presented here may have played an important role in migration and evolution of hominins.
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Migliore J, Baumel A, Juin M, Fady B, Roig A, Duong N, Médail F. Surviving in mountain climate refugia: new insights from the genetic diversity and structure of the relict shrub Myrtus nivellei (Myrtaceae) in the Sahara Desert. PLoS One 2013; 8:e73795. [PMID: 24058489 PMCID: PMC3776782 DOI: 10.1371/journal.pone.0073795] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 07/23/2013] [Indexed: 11/27/2022] Open
Abstract
The identification of past glacial refugia has become a key topic for conservation under environmental change, since they contribute importantly to shaping current patterns of biodiversity. However, little attention has been paid so far to interglacial refugia despite their key role for the survival of relict species currently occurring in climate refugia. Here, we focus on the genetic consequences of range contraction on the relict populations of the evergreen shrub Myrtus nivellei, endemic in the Saharan mountains since at least the end of the last Green Sahara period, around 5.5 ka B.P. Multilocus genotypes (nuclear microsatellites and AFLP) were obtained from 215 individuals collected from 23 wadis (temporary rivers) in the three main mountain ranges in southern Algeria (the Hoggar, Tassili n'Ajjer and Tassili n'Immidir ranges). Identical genotypes were found in several plants growing far apart within the same wadis, a pattern taken as evidence of clonality. Multivariate analyses and Bayesian clustering revealed that genetic diversity was mainly structured among the mountain ranges, while low isolation by distance was observed within each mountain range. The range contraction induced by the last episode of aridification has likely increased the genetic isolation of the populations of M. nivellei, without greatly affecting the genetic diversity of the species as a whole. The pattern of genetic diversity observed here suggests that high connectivity may have prevailed during humid periods, which is consistent with recent paleoenvironmental reconstructions.
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Affiliation(s)
- Jérémy Migliore
- Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale (IMBE), Aix-Marseille Université, UMR CNRS 7263/IRD 237/Avignon Université, Campus Aix - Technopôle de l’Environnement Arbois-Méditerranée, Aix-en-Provence, France
| | - Alex Baumel
- Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale (IMBE), Aix-Marseille Université, UMR CNRS 7263/IRD 237/Avignon Université, Campus Aix - Technopôle de l’Environnement Arbois-Méditerranée, Aix-en-Provence, France
| | - Marianick Juin
- Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale (IMBE), Aix-Marseille Université, UMR CNRS 7263/IRD 237/Avignon Université, Campus Aix - Technopôle de l’Environnement Arbois-Méditerranée, Aix-en-Provence, France
| | - Bruno Fady
- INRA, UR 629, Ecologie des Forêts Méditerranéennes (URFM), Site Agroparc - Domaine Saint Paul, Avignon, France
| | - Anne Roig
- INRA, UR 629, Ecologie des Forêts Méditerranéennes (URFM), Site Agroparc - Domaine Saint Paul, Avignon, France
| | - Nathalie Duong
- Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale (IMBE), Aix-Marseille Université, UMR CNRS 7263/IRD 237/Avignon Université, Campus Aix - Technopôle de l’Environnement Arbois-Méditerranée, Aix-en-Provence, France
| | - Frédéric Médail
- Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale (IMBE), Aix-Marseille Université, UMR CNRS 7263/IRD 237/Avignon Université, Campus Aix - Technopôle de l’Environnement Arbois-Méditerranée, Aix-en-Provence, France
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Were rivers flowing across the Sahara during the last interglacial? Implications for human migration through Africa. PLoS One 2013; 8:e74834. [PMID: 24040347 PMCID: PMC3770569 DOI: 10.1371/journal.pone.0074834] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 08/05/2013] [Indexed: 11/19/2022] Open
Abstract
Human migration north through Africa is contentious. This paper uses a novel palaeohydrological and hydraulic modelling approach to test the hypothesis that under wetter climates c.100,000 years ago major river systems ran north across the Sahara to the Mediterranean, creating viable migration routes. We confirm that three of these now buried palaeo river systems could have been active at the key time of human migration across the Sahara. Unexpectedly, it is the most western of these three rivers, the Irharhar river, that represents the most likely route for human migration. The Irharhar river flows directly south to north, uniquely linking the mountain areas experiencing monsoon climates at these times to temperate Mediterranean environments where food and resources would have been abundant. The findings have major implications for our understanding of how humans migrated north through Africa, for the first time providing a quantitative perspective on the probabilities that these routes were viable for human habitation at these times.
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Abstract
The role of savannas during the course of early human evolution has been debated for nearly a century, in part because of difficulties in characterizing local ecosystems from fossil and sediment records. Here, we present high-resolution lipid biomarker and isotopic signatures for organic matter preserved in lake sediments at Olduvai Gorge during a key juncture in human evolution about 2.0 Ma--the emergence and dispersal of Homo erectus (sensu lato). Using published data for modern plants and soils, we construct a framework for ecological interpretations of stable carbon-isotope compositions (expressed as δ(13)C values) of lipid biomarkers from ancient plants. Within this framework, δ(13)C values for sedimentary leaf lipids and total organic carbon from Olduvai Gorge indicate recurrent ecosystem variations, where open C(4) grasslands abruptly transitioned to closed C(3) forests within several hundreds to thousands of years. Carbon-isotopic signatures correlate most strongly with Earth's orbital geometry (precession), and tropical sea-surface temperatures are significant secondary predictors in partial regression analyses. The scale and pace of repeated ecosystem variations at Olduvai Gorge contrast with long-held views of directional or stepwise aridification and grassland expansion in eastern Africa during the early Pleistocene and provide a local perspective on environmental hypotheses of human evolution.
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Sánchez-Quinto F, Botigué LR, Civit S, Arenas C, Ávila-Arcos MC, Bustamante CD, Comas D, Lalueza-Fox C. North African populations carry the signature of admixture with Neandertals. PLoS One 2012; 7:e47765. [PMID: 23082212 PMCID: PMC3474783 DOI: 10.1371/journal.pone.0047765] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 09/20/2012] [Indexed: 11/19/2022] Open
Abstract
One of the main findings derived from the analysis of the Neandertal genome was the evidence for admixture between Neandertals and non-African modern humans. An alternative scenario is that the ancestral population of non-Africans was closer to Neandertals than to Africans because of ancient population substructure. Thus, the study of North African populations is crucial for testing both hypotheses. We analyzed a total of 780,000 SNPs in 125 individuals representing seven different North African locations and searched for their ancestral/derived state in comparison to different human populations and Neandertals. We found that North African populations have a significant excess of derived alleles shared with Neandertals, when compared to sub-Saharan Africans. This excess is similar to that found in non-African humans, a fact that can be interpreted as a sign of Neandertal admixture. Furthermore, the Neandertal's genetic signal is higher in populations with a local, pre-Neolithic North African ancestry. Therefore, the detected ancient admixture is not due to recent Near Eastern or European migrations. Sub-Saharan populations are the only ones not affected by the admixture event with Neandertals.
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Affiliation(s)
| | - Laura R. Botigué
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
| | - Sergi Civit
- Departament d'Estadística, Universitat de Barcelona, Barcelona, Spain
| | - Conxita Arenas
- Departament d'Estadística, Universitat de Barcelona, Barcelona, Spain
| | - María C. Ávila-Arcos
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Carlos D. Bustamante
- Department of Genetics, Stanford University, Stanford, California, United States of America
| | - David Comas
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
| | - Carles Lalueza-Fox
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
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42
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Scally A, Durbin R. Revising the human mutation rate: implications for understanding human evolution. Nat Rev Genet 2012; 13:745-53. [PMID: 22965354 DOI: 10.1038/nrg3295] [Citation(s) in RCA: 413] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
It is now possible to make direct measurements of the mutation rate in modern humans using next-generation sequencing. These measurements reveal a value that is approximately half of that previously derived from fossil calibration, and this has implications for our understanding of demographic events in human evolution and other aspects of population genetics. Here, we discuss the implications of a lower-than-expected mutation rate in relation to the timescale of human evolution.
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43
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Blome MW, Cohen AS, Tryon CA, Brooks AS, Russell J. The environmental context for the origins of modern human diversity: A synthesis of regional variability in African climate 150,000–30,000 years ago. J Hum Evol 2012; 62:563-92. [DOI: 10.1016/j.jhevol.2012.01.011] [Citation(s) in RCA: 202] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 12/02/2011] [Accepted: 01/24/2012] [Indexed: 11/27/2022]
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Elwali NE, Mariani Costantini R, Di Gioacchino M. Environment and immune-mediated diseases in Sub-Saharan Africa. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 423:190-192. [PMID: 20961598 DOI: 10.1016/j.scitotenv.2010.08.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 08/26/2010] [Indexed: 05/30/2023]
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45
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Single-grain OSL chronologies for Middle Palaeolithic deposits at El Mnasra and El Harhoura 2, Morocco: Implications for Late Pleistocene human–environment interactions along the Atlantic coast of northwest Africa. J Hum Evol 2012; 62:377-94. [DOI: 10.1016/j.jhevol.2011.12.001] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 11/21/2011] [Accepted: 12/05/2011] [Indexed: 11/23/2022]
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Shape variation in Aterian tanged tools and the origins of projectile technology: a morphometric perspective on stone tool function. PLoS One 2012. [PMID: 22216161 DOI: 10.1371/journal.pone.0029029.] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Recent findings suggest that the North African Middle Stone Age technocomplex known as the Aterian is both much older than previously assumed, and certainly associated with fossils exhibiting anatomically modern human morphology and behavior. The Aterian is defined by the presence of 'tanged' or 'stemmed' tools, which have been widely assumed to be among the earliest projectile weapon tips. The present study systematically investigates morphological variation in a large sample of Aterian tools to test the hypothesis that these tools were hafted and/or used as projectile weapons. METHODOLOGY/PRINCIPAL FINDINGS Both classical morphometrics and Elliptical Fourier Analysis of tool outlines are used to show that the shape variation in the sample exhibits size-dependent patterns consistent with a reduction of the tools from the tip down, with the tang remaining intact. Additionally, the process of reduction led to increasing side-to-side asymmetries as the tools got smaller. Finally, a comparison of shape-change trajectories between Aterian tools and Late Paleolithic arrowheads from the North German site of Stellmoor reveal significant differences in terms of the amount and location of the variation. CONCLUSIONS/SIGNIFICANCE The patterns of size-dependent shape variation strongly support the functional hypothesis of Aterian tools as hafted knives or scrapers with alternating active edges, rather than as weapon tips. Nevertheless, the same morphological patterns are interpreted as one of the earliest evidences for a hafting modification, and for the successful combination of different raw materials (haft and stone tip) into one implement, in itself an important achievement in the evolution of hominin technologies.
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47
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A Northeast Saharan Perspective on Environmental Variability in North Africa and its Implications for Modern Human Origins. MODERN ORIGINS 2012. [DOI: 10.1007/978-94-007-2929-2_2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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48
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Iovita R. Shape variation in Aterian tanged tools and the origins of projectile technology: a morphometric perspective on stone tool function. PLoS One 2011; 6:e29029. [PMID: 22216161 PMCID: PMC3246439 DOI: 10.1371/journal.pone.0029029] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 11/19/2011] [Indexed: 11/23/2022] Open
Abstract
Background Recent findings suggest that the North African Middle Stone Age technocomplex known as the Aterian is both much older than previously assumed, and certainly associated with fossils exhibiting anatomically modern human morphology and behavior. The Aterian is defined by the presence of ‘tanged’ or ‘stemmed’ tools, which have been widely assumed to be among the earliest projectile weapon tips. The present study systematically investigates morphological variation in a large sample of Aterian tools to test the hypothesis that these tools were hafted and/or used as projectile weapons. Methodology/Principal Findings Both classical morphometrics and Elliptical Fourier Analysis of tool outlines are used to show that the shape variation in the sample exhibits size-dependent patterns consistent with a reduction of the tools from the tip down, with the tang remaining intact. Additionally, the process of reduction led to increasing side-to-side asymmetries as the tools got smaller. Finally, a comparison of shape-change trajectories between Aterian tools and Late Paleolithic arrowheads from the North German site of Stellmoor reveal significant differences in terms of the amount and location of the variation. Conclusions/Significance The patterns of size-dependent shape variation strongly support the functional hypothesis of Aterian tools as hafted knives or scrapers with alternating active edges, rather than as weapon tips. Nevertheless, the same morphological patterns are interpreted as one of the earliest evidences for a hafting modification, and for the successful combination of different raw materials (haft and stone tip) into one implement, in itself an important achievement in the evolution of hominin technologies.
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Affiliation(s)
- Radu Iovita
- Department of Palaeolithic Studies, Römisch-Germanisches Zentralmuseum Mainz, Schloss Monrepos, Neuwied, Germany.
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49
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Beyin A. Upper Pleistocene Human Dispersals out of Africa: A Review of the Current State of the Debate. INTERNATIONAL JOURNAL OF EVOLUTIONARY BIOLOGY 2011; 2011:615094. [PMID: 21716744 PMCID: PMC3119552 DOI: 10.4061/2011/615094] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 01/22/2011] [Accepted: 02/24/2011] [Indexed: 12/31/2022]
Abstract
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 center of the discussion lies the question of whether eastern Africa alone was the source of Upper Pleistocene human dispersals into Eurasia or were there other loci of human expansions outside of Africa? The reviewed literature hints at two modes of early modern human colonization of Eurasia in the Upper Pleistocene: (i) from multiple Homo sapiens source populations that had entered Arabia, South Asia, and the Levant prior to and soon after the onset of the Last Interglacial (MIS-5), (ii) from a rapid dispersal out of East Africa via the Southern Route (across the Red Sea basin), dating to ~74–60 kya.
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Affiliation(s)
- Amanuel Beyin
- Turkana Basin Institute, Stony Brook University, SBS Building 5th Floor, Stony Brook, NY 11794, USA
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Ancient watercourses and biogeography of the Sahara explain the peopling of the desert. Proc Natl Acad Sci U S A 2010; 108:458-62. [PMID: 21187416 DOI: 10.1073/pnas.1012231108] [Citation(s) in RCA: 321] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Evidence increasingly suggests that sub-Saharan Africa is at the center of human evolution and understanding routes of dispersal "out of Africa" is thus becoming increasingly important. The Sahara Desert is considered by many to be an obstacle to these dispersals and a Nile corridor route has been proposed to cross it. Here we provide evidence that the Sahara was not an effective barrier and indicate how both animals and humans populated it during past humid phases. Analysis of the zoogeography of the Sahara shows that more animals crossed via this route than used the Nile corridor. Furthermore, many of these species are aquatic. This dispersal was possible because during the Holocene humid period the region contained a series of linked lakes, rivers, and inland deltas comprising a large interlinked waterway, channeling water and animals into and across the Sahara, thus facilitating these dispersals. This system was last active in the early Holocene when many species appear to have occupied the entire Sahara. However, species that require deep water did not reach northern regions because of weak hydrological connections. Human dispersals were influenced by this distribution; Nilo-Saharan speakers hunting aquatic fauna with barbed bone points occupied the southern Sahara, while people hunting Savannah fauna with the bow and arrow spread southward. The dating of lacustrine sediments show that the "green Sahara" also existed during the last interglacial (∼125 ka) and provided green corridors that could have formed dispersal routes at a likely time for the migration of modern humans out of Africa.
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