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    ABSTRACT: Debate over the taxonomic status of the Neanderthals has been incessant since the initial discovery of the type specimens, with some arguing they should be included within our species (i.e. Homo sapiens neanderthalensis) and others believing them to be different enough to constitute their own species (Homo neanderthalensis). This synthesis addresses the process of speciation as well as incorporating information on the differences between species and subspecies, and the criteria used for discriminating between the two. It also analyses the evidence for Neanderthal–AMH hybrids, and their relevance to the species debate, before discussing morphological and genetic evidence relevant to the Neanderthal taxonomic debate. The main conclusion is that Neanderthals fulfil all major requirements for species status. The extent of interbreeding between the two populations is still highly debated, and is irrelevant to the issue at hand, as the Biological Species Concept allows for an expected amount of interbreeding between species.
    Journal of Anthropological Archaeology 01/2014; 35:32–50.
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    ABSTRACT: It is commonly accepted that, following the end of the Pleistocene, semi-arid deciduous oak woodlands did not spread in the Irano-Anatolian region of Southwest Asia as quickly as they did in the Levantine Mediterranean littoral, despite the fact that climatic improvement occurred broadly at the same time in both regions. Prehistoric impacts on woodland vegetation (such as woodcutting, burning and clearance for cultivation), the harsh continental climate of inland Southwest Asia and its distance from late Pleistocene arboreal refugia have all been discussed in the literature as likely causes of the delay. In this paper we argue that semi-arid deciduous oak woodlands should not be viewed as part of the “natural” vegetation of the Irano-Anatolian region that has been progressively destroyed by millennia of human activities since the Neolithic. They represent instead one of the earliest anthropogenic vegetation types in Southwest Asia, one that owes its very existence to prehistoric landscape practices other scholars commonly label as “destructive”. Drawing on anthracological, pollen and modern vegetation data from central Anatolia we describe how the post-Pleistocene species-rich and structurally diverse temperate semi-arid savanna grasslands were gradually substituted by low-diversity, even-aged Quercus-dominated parklands and wood pastures in the course of the early Holocene. Economic strategies that encouraged the establishment and spread of deciduous oaks included sheep herding that impacted on grass and forb vegetation, the controlling of competing arboreal vegetation through woodcutting, and woodland management practices such as coppicing, pollarding and shredding that enhanced Quercus vegetative propagation, crown and stem growth. Understanding the origin and evolution of the Irano-Anatolian semi-arid oak woodlands of Southwest Asia is of critical importance for reconstructing the changing ecologies and geographical distributions of the progenitors of domesticated crop species, and the nature and scale of early agricultural impacts on the landscape.
    Quaternary Science Reviews 01/2014; 90:158–182.
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    ABSTRACT: The popular theory that complex tool-making and language co-evolved in the human lineage rests on the hypothesis that both skills share underlying brain processes and systems. However, language and stone tool-making have so far only been studied separately using a range of neuroimaging techniques and diverse paradigms. We present the first-ever study of brain activation that directly compares active Acheulean tool-making and language. Using functional transcranial Doppler ultrasonography (fTCD), we measured brain blood flow lateralization patterns (hemodynamics) in subjects who performed two tasks designed to isolate the planning component of Acheulean stone tool-making and cued word generation as a language task. We show highly correlated hemodynamics in the initial 10 seconds of task execution. Stone tool-making and cued word generation cause common cerebral blood flow lateralization signatures in our participants. This is consistent with a shared neural substrate for prehistoric stone tool-making and language, and is compatible with language evolution theories that posit a co-evolution of language and manual praxis. In turn, our results support the hypothesis that aspects of language might have emerged as early as 1.75 million years ago, with the start of Acheulean technology.
    PLoS ONE 01/2013; 8(8):e72693.
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    ABSTRACT: Herries provides a timely review of the archaeological and dating evidence of the transition from the Acheulean to the Middle Stone Age (MSA) in southern Africa, however, in relation to the site of Twin Rivers, Zambia he makes several fundamental errors of interpretation that demand correction. The stratigraphic sequence of the site is admittedly complex, but it deserves a more careful analysis than that offered by Herries. This detailed response by the most recent excavator of the site addresses Herries critique by placing the site in its historical context and then dealing with the central issue of the association of dated speleothem with the surviving archaeological deposits. Herries is shown to have mistakenly combined the dates from two separate cave passages and to have misunderstood the published sections, plans, and taphonomic assessment of each excavation area. His reinterpretation of the site as being significantly younger than published is based on a conflation of unrelated data.
    International journal of evolutionary biology. 01/2012; 2012:230156.
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    ABSTRACT: The course of hominin evolution has involved successive migrations towards higher absolute latitudes over the past three million years. Poorer habitat quality further from the equator has led to the necessity for groups occupying higher latitudes to live at lower population densities. Coupled with a trend towards increasing group size over this time period, this tendency towards expansion has led to exponential increases in the area requirements of hominin groups, and a concomitant need to adjust foraging patterns. The current analyses suggest that the development of increasingly complex, multi-level fission-fusion social systems could have freed hominins of the foraging constraints imposed by large group sizes and low population densities. Analyses of the fossil record suggest latitudinally-driven differences in area requirements of the australopithecines from East and South Africa, and African and Asian Homo erectus. In contrast, chronologically-driven differences appear between H. erectus as a whole and Homo heidelbergensis, and between H. heidelbergensis and the Neanderthals. These results are discussed in relation to studies of the foraging patterns of primates and hunter-gatherers.
    Journal of Human Evolution 12/2011; 62(2):191-200.
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    ABSTRACT: Over geological timescales, organisms encounter periodic shifts in selective conditions driven by environmental change. The variability selection hypothesis suggests that increases in environmental fluctuation have led to the evolution of complex, flexible behaviours able to respond to novel and unpredictable adaptive settings. This hypothesis is tested via the framework of a single locus genetic model in which an invading 'versatilist' allele competes with two opposed specialists in a selection regime driven by a fluctuating environment, modelled initially as a sine wave and subsequently as an empirical climate curve covering the past 5 million years. Results demonstrate that generalist alleles achieve fixation in the sine wave environment, whilst versatilist alleles do so in the empirical environment, even at a range of very low fitness advantages over the basic generalist template. Variability selection is found to be a particularly strong force between approximately 2.5 and 1.2 Ma (millions of years ago). These results are discussed in relation to the spread of Oldowan lithics and the patterns of speciation and extinction documented in the hominin fossil record. It is suggested that the flexibility required for survival in a variable climatic regime may have been a stimulus to the development of the first stone tool technologies, whilst the ecological opportunities provided by heightened variability may have been a factor in prompting the hominin adaptive radiation evidenced during this period.
    Journal of Human Evolution 06/2011; 61(3):306-19.
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    ABSTRACT: Flake based assemblages (Mode 1) comprise the earliest stone technologies known, with well-dated Oldowan sites occurring in eastern Africa between ~2.6-1.7 Ma, and in less securely dated contexts in central, southern and northern Africa. Our understanding of the spread and local development of this technology outside East Africa remains hampered by the lack of reliable numerical dating techniques applicable to non-volcanic deposits. This study applied the still relatively new technique of cosmogenic nuclide burial dating ((10)Be/(26)Al) to calculate burial ages for fluvial gravels containing Mode 1 artefacts in the Luangwa Valley, Zambia. The Manzi River, a tributary of the Luangwa River, has exposed a 4.7 m deep section of fluvial sands with discontinuous but stratified gravel layers bearing Mode 1, possibly Oldowan, artefacts in the basal layers. An unconformity divides the Manzi section, separating Mode 1 deposits from overlying gravels containing Mode 3 (Middle Stone Age) artefacts. No diagnostic Mode 2 (Acheulean) artefacts were found. Cosmogenic nuclide burial dating was attempted for the basal gravels as well as exposure ages for the upper Mode 3 gravels, but was unsuccessful. The complex depositional history of the site prevented the calculation of reliable age models. A relative chronology for the full Manzi sequence was constructed, however, from the magnetostratigraphy of the deposit (N>R>N sequence). Isothermal thermoluminescence (ITL) dating of the upper Mode 3 layers also provided consistent results (~78 ka). A coarse but chronologically coherent sequence now exists for the Manzi section with the unconformity separating probable mid- or early Pleistocene deposits below from late Pleistocene deposits above. The results suggest Mode 1 technology in the Luangwa Valley may post-date the Oldowan in eastern and southern Africa. The dating programme has contributed to a clearer understanding of the geomorphological processes that have shaped the valley and structured its archaeological record.
    Journal of Human Evolution 03/2011; 60(5):549-70.
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    ABSTRACT: Archaeologists are accustomed to considering both the spatial distributions of sites and the temporal distributions of dates as means of analysing the dynamics of prehistoric societies. However, spatial and temporal approaches have thus far remained largely separate, rather than being combined within a single, unified framework. A formal methodology is outlined that combines univariate kernel density estimation based on radiocarbon dates with bivariate kernel density estimation based on spatial site coordinates; the approach allows archaeologists to arrive at reconstructed land-use distributions through time that not only correct for the problematic issue of site contemporaneity, but also reflect the continuous nature of the archaeological record. The model is implemented using as a data set a series of sites from the Mesolithic of Atlantic Iberia; the results demonstrate that it is capable of providing key insights into changing patterns of land use that are not apparent from either the temporal or the spatial perspective alone.
    Archaeometry 02/2011; 53(5):1012 - 1030.
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    ABSTRACT: Recent research suggests that contemporary human social groups are structured according to principles of fission and fusion that are also observed in some of our primate relatives, raising the possibility that such social systems have been a feature of hominin society throughout prehistory. The current paper examines the possibility of identifying archaeological signatures of multi-level social structures through the examination of site size distributions. Data on the sizes of Irish Bronze Age stone circles and predictions for the size of aggregations they could accommodate are compared with simulations parameterized using data on modern human groups. The results suggest that the presence of hierarchically inclusive, multi-level social structures provides a better explanation for the data than more traditional archaeological accounts based on the rank-size rule and related inferences concerning the emergence of political elites.
    Journal of Anthropological Archaeology - J ANTHROPOL ARCHAEOL. 01/2011; 30(1):44-61.
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    ABSTRACT: The Holocene fire regime is thought to have had a key role in deforestation and shrubland expansion in Galicia (NW Spain) but the contribution of past societies to vegetation burning remains poorly understood. This may be, in part, due to the fact that detailed fire records from areas in close proximity to archaeological sites are scarce. To fill this gap, we performed charcoal analysis in five colluvial soils from an archaeological area (Campo Lameiro) and compared the results to earlier studies from this area and palaeo-ecological literature from NW Spain. This analysis allowed for the reconstruction of the vegetation and fire dynamics in the area during the last ca 11 000 yrs. In the Early Holocene, Fabaceae and Betula sp. were dominant in the charcoal record. Quercus sp. started to replace these species around 10 000 cal BP, forming a deciduous forest that prevailed during the Holocene Thermal Maximum until ∼5500 cal BP. Following that, several cycles of potentially fire-induced forest regression with subsequent incomplete recovery eventually led to the formation of an open landscape dominated by shrubs (Erica sp. and Fabaceae). Major episodes of forest regression were (1) ∼5500–5000 cal BP, which marks the mid-Holocene cooling after the Holocene Thermal Maximum, but also the period during which agropastoral activities in NW Spain became widespread, and (2) ∼2000–1500 cal BP, which corresponds roughly to the end of the Roman Warm Period and the transition from the Roman to the Germanic period. The low degree of chronological precision, which is inherent in fire history reconstructions from colluvial soils, made it impossible to distinguish climatic from human-induced fires. Nonetheless, the abundance of synanthropic pollen indicators (e.g. Plantago lanceolata and Urtica dioica) since at least ∼6000 cal BP strongly suggests that humans used fire to generate and maintain pasture.
    Quaternary Science Reviews 01/2011;
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