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Comparative dental study between Homo antecessor and Chinese Homo erectus: Nonmetric features and geometric morphometrics. J Hum Evol 2021; 161:103087. [PMID: 34742110 DOI: 10.1016/j.jhevol.2021.103087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 09/13/2021] [Accepted: 09/18/2021] [Indexed: 11/24/2022]
Abstract
The Chinese Middle Pleistocene fossils from Hexian, Xichuan, Yiyuan, and Zhoukoudian have been generally classified as Homo erectus s.s. These hominins share some primitive features with other Homo specimens, but they also display unique cranial and dental traits. Thus, the Chinese Middle Pleistocene hominins share with other European and Asian hominin populations the so-called 'Eurasian dental pattern'. The late Early Pleistocene hominins from Gran Dolina-TD6.2 (Spain), representing the species Homo antecessor, also exhibit the Eurasian dental pattern, which may suggest common roots. To assess phylogenetic affinities of these two taxa, we evaluated and compared nonmetric and metric dental features and interpreted morphological differences within a comparative hominin framework. We determined that the robust roots of the molars, the shelf-like protostylid, the dendrite-like pattern of the enamel-dentine junction surface of the upper fourth premolars and molars, the strongly folded dentine of the labial surface of the upper incisors, and the rare occurrence of a mid-trigonid crest in the lower molars, are all characteristic of Chinese H. erectus. With regard to H. antecessor, we observed the consistent expression of a continuous mid-trigonid crest, the absence of a cingulum in the upper canines, a complex root pattern of the lower premolars, and a rhomboidal occlusal contour and occlusal polygon and protrusion in the external outline of a large a bulging hypocone in the first and second upper molars. Using two-dimensional geometric morphometrics, we further demonstrated that H. antecessor falls outside the range of variation of Chinese H. erectus for occlusal crown outline shape, the orientation of occlusal grooves, and relative locations of anterior and posterior foveae in the P4s, P3s, M1s, M2s, and M2s. Given their geographic and temporal separation, the differences between these two species suggest their divergence occurred at some point in the Early Pleistocene, and thereafter they followed different evolutionary paths.
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Crabtree SA, White DA, Bradshaw CJA, Saltré F, Williams AN, Beaman RJ, Bird MI, Ulm S. Landscape rules predict optimal superhighways for the first peopling of Sahul. Nat Hum Behav 2021; 5:1303-1313. [PMID: 33927367 DOI: 10.1038/s41562-021-01106-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 03/24/2021] [Indexed: 02/02/2023]
Abstract
Archaeological data and demographic modelling suggest that the peopling of Sahul required substantial populations, occurred rapidly within a few thousand years and encompassed environments ranging from hyper-arid deserts to temperate uplands and tropical rainforests. How this migration occurred and how humans responded to the physical environments they encountered have, however, remained largely speculative. By constructing a high-resolution digital elevation model for Sahul and coupling it with fine-scale viewshed analysis of landscape prominence, least-cost pedestrian travel modelling and high-performance computing, we create over 125 billion potential migratory pathways, whereby the most parsimonious routes traversed emerge. Our analysis revealed several major pathways-superhighways-transecting the continent, that we evaluated using archaeological data. These results suggest that the earliest Australian ancestors adopted a set of fundamental rules shaped by physiological capacity, attraction to visually prominent landscape features and freshwater distribution to maximize survival, even without previous experience of the landscapes they encountered.
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Affiliation(s)
- Stefani A Crabtree
- Department of Environment and Society, Utah State University, Logan, UT, USA. .,The Santa Fe Institute, Santa Fe, NM, USA. .,ARC Centre of Excellence for Australian Biodiversity and Heritage, James Cook University, Cairns, Queensland, Australia. .,Université de Paris, INSERM U1284, Center for Research and Interdisciplinarity (CRI), Paris, France.
| | - Devin A White
- Autonomous Sensing and Perception, Sandia National Laboratories, Albuquerque, NM, USA.,Department of Anthropology, University of Tennessee, Knoxville, Knoxville, TN, USA
| | - Corey J A Bradshaw
- ARC Centre of Excellence for Australian Biodiversity and Heritage, Flinders University, Adelaide, South Australia, Australia.,Global Ecology Partuyarta Ngadluku Wardli Kuu, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Frédérik Saltré
- ARC Centre of Excellence for Australian Biodiversity and Heritage, Flinders University, Adelaide, South Australia, Australia.,Global Ecology Partuyarta Ngadluku Wardli Kuu, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Alan N Williams
- Climate Change Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia.,ARC Centre of Excellence for Australian Biodiversity and Heritage, University of New South Wales, Sydney, Australia.,EMM Consulting Pty Ltd, St Leonards, New South Wales, Australia
| | - Robin J Beaman
- College of Science and Engineering, James Cook University, Cairns, Queensland, Australia
| | - Michael I Bird
- ARC Centre of Excellence for Australian Biodiversity and Heritage, James Cook University, Cairns, Queensland, Australia.,College of Science and Engineering, James Cook University, Cairns, Queensland, Australia
| | - Sean Ulm
- ARC Centre of Excellence for Australian Biodiversity and Heritage, James Cook University, Cairns, Queensland, Australia.,College of Arts, Society and Education, James Cook University, Cairns, Queensland, Australia
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Hölzchen E, Hertler C, Mateos A, Rodríguez J, Berndt JO, Timm IJ. Discovering the opposite shore: How did hominins cross sea straits? PLoS One 2021; 16:e0252885. [PMID: 34191820 PMCID: PMC8244915 DOI: 10.1371/journal.pone.0252885] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/25/2021] [Indexed: 11/19/2022] Open
Abstract
Understanding hominin expansions requires the comprehension of movement processes at different scales. In many models of hominin expansion these processes are viewed as being determined by large-scale effects, such as changes in climate and vegetation spanning continents and thousands or even millions of years. However, these large-scale patterns of expansions also need to be considered as possibly resulting from the accumulation of small-scale decisions of individual hominins. Moving on a continental scale may for instance involve crossing a water barrier. We present a generalized agent-based model for simulating the crossing of a water barrier where the agents represent the hominin individuals. The model can be configured to represent a variety of movement modes across water. Here, we compare four different behavioral scenarios in conjunction with a set of water barrier configurations, in which agents move in water by either paddling, drifting, swimming or rafting. We introduce the crossing-success-rate (CSR) to quantify the performance in water crossing. Our study suggests that more focus should be directed towards the exploration of behavioral models for hominins, as directionality may be a more powerful factor for crossing a barrier than environmental opportunities alone. A prerequisite for this is to perceive the opposite shore. Furthermore, to provide a comprehensive understanding of hominin expansions, the CSR allows for the integration of results obtained from small-scale simulations into large-scale models for hominin expansion.
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Affiliation(s)
- Ericson Hölzchen
- Faculty of Biosciences, Department of Paleobiology and Environment, Institute of Ecology, Evolution and Diversity, Goethe University Frankfurt, Frankfurt am Main, Germany
- The Role of Culture in Early Expansion of Humans (ROCEEH), Senckenberg Research Institute, Frankfurt am Main, Germany
- The Role of Culture in Early Expansion of Humans (ROCEEH), Heidelberg Academy of Sciences, Heidelberg, Germany
- * E-mail:
| | - Christine Hertler
- The Role of Culture in Early Expansion of Humans (ROCEEH), Senckenberg Research Institute, Frankfurt am Main, Germany
- The Role of Culture in Early Expansion of Humans (ROCEEH), Heidelberg Academy of Sciences, Heidelberg, Germany
| | - Ana Mateos
- National Research Center on Human Evolution (CENIEH), Burgos, Spain
| | - Jesús Rodríguez
- National Research Center on Human Evolution (CENIEH), Burgos, Spain
| | - Jan Ole Berndt
- Chair for Business Informatics I Trier Lab for Social Simulation (TRILABS), Trier University, Trier, Germany
| | - Ingo J. Timm
- Chair for Business Informatics I Trier Lab for Social Simulation (TRILABS), Trier University, Trier, Germany
- German Research Center for Artificial Intelligence (DFKI) Cognitive Social Simulation (Branch Trier), Trier University, Trier, Germany
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Vialet A, Modesto-Mata M, Martinón-Torres M, Martínez de Pinillos M, Bermúdez de Castro JM. A reassessment of the Montmaurin-La Niche mandible (Haute Garonne, France) in the context of European Pleistocene human evolution. PLoS One 2018; 13:e0189714. [PMID: 29337994 PMCID: PMC5770020 DOI: 10.1371/journal.pone.0189714] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 11/30/2017] [Indexed: 11/19/2022] Open
Abstract
We here present a comparative study of the Montmaurin-LN Middle Pleistocene mandible (Haute-Garonne, France). This mandible, of which its right and left molar series are preserved in situ, was found in La Niche cave (Montmaurin's karst system) in 1949, and was first attributed to the 'Mindel-Riss' interglacial (= MIS 9 to 11) based on its geological context. Later studies based on geological and faunal evidence have attributed the Montmaurin-LN mandible to MIS 7. Following a detailed morphological and metric comparative study of the mandible in the 1970s, it was interpreted in the light of a still limited fossil record and the prevailing paradigm back then. Waiting for geochronological studies in the forthcoming years, here we review the main morphological and metrical features of this mandible and its molars, which have been reassessed in the framework of a remarkably enlarged Pleistocene fossil record since the mandible was first described, and our current, more in-depth understanding of human evolution in Europe. Using a selection of mandibular features with potential taxonomic signal we have found that the Montmaurin-LN mandible shares only a few derived traits with Neandertals. Our analyses reveal that this mandible is more closely related to the ancient specimens from the African and Eurasian Early and Middle Pleistocene, particularly due to the presence of primitive features of the Homo clade. In contrast, the external morphology of the molars is clearly similar to that of Neandertals. The results are assessed in the light of the present competing hypotheses used to explain the European hominin fossil record.
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Affiliation(s)
- Amélie Vialet
- Muséum national d’Histoire naturelle, UMR7194, UPVD, Centre Européen de Recherches Préhistoriques de Tautavel, Paris, France
| | - Mario Modesto-Mata
- Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Paseo de la Sierra de Atapuerca 3, Burgos, Spain
- Equipo Primeros Pobladores de Extremadura (EPPEX), Casa de la Cultura Rodríguez Moñino, Cáceres, Spain
| | - María Martinón-Torres
- Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Paseo de la Sierra de Atapuerca 3, Burgos, Spain
- Department of Anthropology, University College London, London, United Kingdom
- Laboratorio de Evolución Humana (LEH), Departamento de Ciencias Históricas y Geografía, Universidad de Burgos, Hospital del Rey S/N, Burgos, Spain
| | - Marina Martínez de Pinillos
- Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Paseo de la Sierra de Atapuerca 3, Burgos, Spain
- Department of Anthropology, University College London, London, United Kingdom
| | - José-María Bermúdez de Castro
- Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Paseo de la Sierra de Atapuerca 3, Burgos, Spain
- Department of Anthropology, University College London, London, United Kingdom
- * E-mail:
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Bicho N, Cascalheira J, Gonçalves C. Early Upper Paleolithic colonization across Europe: Time and mode of the Gravettian diffusion. PLoS One 2017; 12:e0178506. [PMID: 28542642 PMCID: PMC5443572 DOI: 10.1371/journal.pone.0178506] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 05/15/2017] [Indexed: 11/24/2022] Open
Abstract
This study presents new models on the origin, speed and mode of the wave-of-advance leading to the definitive occupation of Europe's outskirts by Anatomically Modern Humans, during the Gravettian, between c. 37 and 30 ka ago. These models provide the estimation for possible demic dispersal routes for AMH at a stable spread rate of c. 0.7 km/year, with the likely origin in Central Europe at the site of Geissenklosterle in Germany and reaching all areas of the European landscape. The results imply that: 1. The arrival of the Gravettian populations into the far eastern European plains and to southern Iberia found regions with very low human occupation or even devoid of hominins; 2. Human demography was likely lower than previous estimates for the Upper Paleolithic; 3. The likely early AMH paths across Europe followed the European central plains and the Mediterranean coast to reach to the ends of the Italian and Iberian peninsulas.
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Affiliation(s)
- Nuno Bicho
- ICArEHB (Interdisciplinary Center for Archaeology and the Evolution of Human Behavior), Faculdade de Ciências Humanas e Sociais, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
| | - João Cascalheira
- ICArEHB (Interdisciplinary Center for Archaeology and the Evolution of Human Behavior), Faculdade de Ciências Humanas e Sociais, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
| | - Célia Gonçalves
- ICArEHB (Interdisciplinary Center for Archaeology and the Evolution of Human Behavior), Faculdade de Ciências Humanas e Sociais, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
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Climatic variability, plasticity, and dispersal: A case study from Lake Tana, Ethiopia. J Hum Evol 2016; 87:32-47. [PMID: 26472274 DOI: 10.1016/j.jhevol.2015.07.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 03/06/2015] [Accepted: 07/12/2015] [Indexed: 12/23/2022]
Abstract
The numerous dispersal events that have occurred during the prehistory of hominin lineages are the subject of longstanding and increasingly active debate in evolutionary anthropology. As well as research into the dating and geographic extent of such dispersals, there is an increasing focus on the factors that may have been responsible for dispersal. The growing body of detailed regional palaeoclimatic data is invaluable in demonstrating the often close relationship between changes in prehistoric environments and the movements of hominin populations. The scenarios constructed from such data are often overly simplistic, however, concentrating on the dynamics of cyclical contraction and expansion during severe and ameliorated conditions respectively. This contribution proposes a two-stage hypothesis of hominin dispersal in which populations (1) accumulate high levels of climatic tolerance during highly variable climatic phases, and (2) express such heightened tolerance via dispersal in subsequent low-variability phases. Likely dispersal phases are thus proposed to occur during stable climatic phases that immediately follow phases of high climatic variability. Employing high resolution palaeoclimatic data from Lake Tana, Ethiopia, the hypothesis is examined in relation to the early dispersal of Homo sapiens out of East Africa and into the Levant. A dispersal phase is identified in the Lake Tana record between c. 112,550 and c. 96,975 years ago, a date bracket that accords well with the dating evidence for H. sapiens occupation at the sites of Qafzeh and Skhul. Results are discussed in relation to the complex pattern of H. sapiens dispersal out of East Africa, with particular attention paid to the implications of recent genetic chronologies for the origin of non-African modern humans.
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Carotenuto F, Tsikaridze N, Rook L, Lordkipanidze D, Longo L, Condemi S, Raia P. Venturing out safely: The biogeography of Homo erectus dispersal out of Africa. J Hum Evol 2016; 95:1-12. [DOI: 10.1016/j.jhevol.2016.02.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 02/11/2016] [Accepted: 02/21/2016] [Indexed: 11/17/2022]
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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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Wren CD, Xue JZ, Costopoulos A, Burke A. The role of spatial foresight in models of hominin dispersal. J Hum Evol 2014; 69:70-8. [PMID: 24613470 DOI: 10.1016/j.jhevol.2014.02.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 02/07/2014] [Accepted: 02/07/2014] [Indexed: 11/20/2022]
Abstract
Increasingly sophisticated hominin cognition is assumed to play an important role in major dispersal events but it is unclear what that role is. We present an agent-based model showing that there is a close relationship between level of foresight, environmental heterogeneity, and population dispersibility. We explore the dynamics between these three factors and discuss how they may affect the capacity of a hominin population to disperse. Generally, we find that high levels of environmental heterogeneity select for increased foresight and that high levels of foresight tend to reduce dispersibility. This suggests that cognitively complex hominins in heterogeneous environments have low dispersibility relative to cognitively less complex organisms in more homogeneous environments. The model predicts that the environments leading up to major episodes of dispersal, such as the initial hominin dispersal into Eurasia, were likely relatively low in spatial heterogeneity and that the dispersing hominins had relatively low foresight.
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Affiliation(s)
- Colin D Wren
- Department of Anthropology, McGill University, 855 Sherbrooke St. West., Montreal, QC H3A 2T7, Canada.
| | - Julian Z Xue
- Department of Biology, McGill University, Montreal, Canada
| | - Andre Costopoulos
- Department of Anthropology, McGill University, 855 Sherbrooke St. West., Montreal, QC H3A 2T7, Canada
| | - Ariane Burke
- Département d'anthropologie, Université de Montréal, Montréal, Canada
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Bailey GN, Reynolds SC, King GCP. Landscapes of human evolution: models and methods of tectonic geomorphology and the reconstruction of hominin landscapes. J Hum Evol 2010; 60:257-80. [PMID: 20947132 DOI: 10.1016/j.jhevol.2010.01.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Revised: 05/09/2009] [Accepted: 12/10/2009] [Indexed: 11/30/2022]
Abstract
This paper examines the relationship between complex and tectonically active landscapes and patterns of human evolution. We show how active tectonics can produce dynamic landscapes with geomorphological and topographic features that may be critical to long-term patterns of hominin land use, but which are not typically addressed in landscape reconstructions based on existing geological and paleoenvironmental principles. We describe methods of representing topography at a range of scales using measures of roughness based on digital elevation data, and combine the resulting maps with satellite imagery and ground observations to reconstruct features of the wider landscape as they existed at the time of hominin occupation and activity. We apply these methods to sites in South Africa, where relatively stable topography facilitates reconstruction. We demonstrate the presence of previously unrecognized tectonic effects and their implications for the interpretation of hominin habitats and land use. In parts of the East African Rift, reconstruction is more difficult because of dramatic changes since the time of hominin occupation, while fossils are often found in places where activity has now almost ceased. However, we show that original, dynamic landscape features can be assessed by analogy with parts of the Rift that are currently active and indicate how this approach can complement other sources of information to add new insights and pose new questions for future investigation of hominin land use and habitats.
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Affiliation(s)
- Geoffrey N Bailey
- Department of Archaeology, University of York, The King's Manor, York, YO1 7EP, UK.
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Agustí J, Blain HA, Cuenca-Bescós G, Bailon S. Climate forcing of first hominid dispersal in Western Europe. J Hum Evol 2009; 57:815-21. [PMID: 19683790 DOI: 10.1016/j.jhevol.2009.06.005] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 05/07/2009] [Accepted: 04/08/2009] [Indexed: 11/27/2022]
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Maslin MA, Christensen B. Tectonics, orbital forcing, global climate change, and human evolution in Africa: introduction to the African paleoclimate special volume. J Hum Evol 2007; 53:443-64. [PMID: 17915289 DOI: 10.1016/j.jhevol.2007.06.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Revised: 06/15/2007] [Accepted: 06/28/2007] [Indexed: 11/19/2022]
Abstract
The late Cenozoic climate of Africa is a critical component for understanding human evolution. African climate is controlled by major tectonic changes, global climate transitions, and local variations in orbital forcing. We introduce the special African Paleoclimate Issue of the Journal of Human Evolution by providing a background for and synthesis of the latest work relating to the environmental context for human evolution. Records presented in this special issue suggest that the regional tectonics, appearance of C(4) plants in East Africa, and late Cenozoic global cooling combined to produce a long-term drying trend in East Africa. Of particular importance is the uplift associated with the East African Rift Valley formation, which altered wind flow patterns from a more zonal to more meridinal direction. Results in this volume suggest a marked difference in the climate history of southern and eastern Africa, though both are clearly influenced by the major global climate thresholds crossed in the last 3 million years. Papers in this volume present lake, speleothem, and marine paleoclimate records showing that the East African long-term drying trend is punctuated by episodes of short, alternating periods of extreme wetness and aridity. These periods of extreme climate variability are characterized by the precession-forced appearance and disappearance of large, deep lakes in the East African Rift Valley and paralleled by low and high wind-driven dust loads reaching the adjacent ocean basins. Dating of these records show that over the last 3 million years such periods only occur at the times of major global climatic transitions, such as the intensification of Northern Hemisphere Glaciation (2.7-2.5 Ma), intensification of the Walker Circulation (1.9-1.7 Ma), and the Mid-Pleistocene Revolution (1-0.7 Ma). Authors in this volume suggest this onset occurs as high latitude forcing in both Hemispheres compresses the Intertropical Convergence Zone so that East Africa becomes locally sensitive to precessional forcing, resulting in rapid shifts from wet to dry conditions. These periods of extreme climate variability may have provided a catalyst for evolutionary change and driven key speciation and dispersal events amongst mammals and hominins in Africa. In particular, hominin species seem to differentially originate and go extinct during periods of extreme climate variability. Results presented in this volume may represent the basis of a new theory of early human evolution in Africa.
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Affiliation(s)
- Mark A Maslin
- Environmental Change Research Centre, Department of Geography, University College London, UK.
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Theropithecus and 'Out of Africa' dispersal in the Plio-Pleistocene. J Hum Evol 2007; 54:43-77. [PMID: 17868778 DOI: 10.1016/j.jhevol.2007.06.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2006] [Accepted: 05/25/2007] [Indexed: 11/22/2022]
Abstract
Theropithecus oswaldi was one of the most widely distributed Plio-Pleistocene primates, found in southern, East, and North Africa, as well as in Spain, India, and possibly Italy. Such a large geographic range for a single primate species is highly unusual. Here, the nature and timing of its dispersal is examined using the Stepping Out cellular automata model. A hypothetical dispersal of T. darti is also modelled to assess whether the late Pliocene might have been a more favorable period for Afro-Eurasian dispersal than the early Pleistocene. Stepping Out draws on climatic and biome reconstruction to provide the paleovegetative and climatic background necessary for the simulations, and model parameters for T. oswaldi and T. darti were set a priori on the basis of their fossil records and paleobiologies. The simulations indicate that T. darti could have readily left Africa in the Pliocene, and that it swiftly reaches Asia. A European T. darti colonization was less certain and less rapid. The simulated T. oswaldi dispersal out of Africa was slower, but nonetheless T. oswaldi arrived at Mirzapur within the time period indicated by the fossil record. Using the a priori parameters, T. oswaldi did not arrive at the European sites of Cueva Victoria and Pirro Nord. It cannot be discounted, therefore, that some of the European fossils are a result of an earlier T. darti dispersal. The simulations also showed that in order for Theropithecus to reach Europe, it needed to be tolerant of a relatively wide range of habitats. In addition, our finding that Asian colonization was more rapid and more probable parallels the information from the hominin fossil record, in which the fossils from Asia predate those from Europe by several hundred thousand years.
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