Risk based testing for Mycobacterium bovis following a clinical case in a zoological garden

This document is the version of a published work that appeared in final form in Journal of Zoo and Aquarium Research. To access the final edited and published work see http://dx.doi.org/10.19227/jzar.v2i1.62Mycobacterium bovis is a strictly controlled disease. Outbreaks in zoos result in animal movement bans, disease investigation and euthanasia of infected animals. Both specific tuberculosis legislation and European Directive 92/65, often known as the "Balai" directive, require zoos to be free from tuberculosis in order to import and export animals. This paper describes the use of a risk based targeted testing programme for tuberculosis following a confirmed case of disease. This regime ensured a comprehensive but proportionate disease investigation developed through close co-operation with government veterinary officials, therefore limiting the impact of anaesthetic procedures and animal handling required to complete the necessary testing

Palaeoclimates, plasticity, and the early dispersal of Homo sapiens

The origin and initial dispersal of Homo sapiens out of East Africa and into the Levant remains a major research focus in evolutionary anthropology. There is little doubt that climatic changes played a role in facilitating this dispersal, but the specific dynamics remain poorly understood. This contribution surveys the fossil and genetic evidence for the origin and dispersal of modern humans, and situates this evidence within the context of biological theories of plasticity and dispersal. It is shown that certain climatic and environmental conditions are expected to lead to the evolution of plastic strategies, and that such strategies are characteristic of successfully dispersing species. A model is formulated that allows for the identification of features in climatic records that are conducive to the evolution of plasticity, and thus to the development of dispersal capabilities. Using as an example a palaeoclimatic record from Lake Tana, Ethiopia, the model is used to pinpoint the chronology of likely periods of dispersal from East Africa. Results indicate the presence of a dispersal phase c.97e105 ka, a date that fits well with the initial modern human colonisation of the Levant shortly after 100 ka. Implications of recent genetic chronologies for the origin of non-African modern humans and the archaeological evidence for possible routes out of Africa are discussed in this context

Ecological drivers of hunter-gatherer lithic technology from the Middle and Later Stone Age in Central Africa

Central Africa is a key region for examining patterns of hunter-gatherer inhabitation and engagement with ecological diversity and environmental change. In contrast to adjacent regions, however, the archaeological record of prehistoric hunter-gatherer populations in Central Africa is underrepresented in studies of recent human evolution. This limited engagement with Central African archaeological records in part stems from the complexities of identifying, excavating, and dating hunter-gatherer sites in what are today often heavily forested environments, a focus on named stone tool industries from undated sites to structure the record, and highly limited means to associate dated hunter-gatherer occupations with proxy records of environmental conditions. Here, we present a novel synthesis of prehistoric hunter-gatherer stone tool assemblages from dated Central African sites and use climate model datasets to illuminate the environmental and ecological landscapes in which they were deployed. Our results suggest a significant ecological shift occurred from 14,000 years ago onwards, associated with a greater engagement with broadleaf forests. We examine the extent to which a range of geographic and paleoclimatic drivers can explain patterns of gross assemblage composition and the appearance of individual lithic technologies highlighting the significant role of changes in altitude, precipitation, seasonality, and ecology. Notably, considerable continuity can be observed between the habitat ranges of contemporary hunter-gatherer populations in Central Africa and prehistoric occupations that significantly precede the appearance of farming lifeways in the region

Evaluating refugia in recent human evolution in Africa

Homo sapiens have adapted to an incredible diversity of habitats around the globe. This capacity to adapt to different landscapes is clearly expressed within Africa, with Late Pleistocene Homo sapiens populations occupying savannahs, woodlands, coastlines and mountainous terrain. As the only area of the world where Homo sapiens have clearly persisted through multiple glacial-interglacial cycles, Africa is the only continent where classic refugia models can be formulated and tested to examine and describe changing patterns of past distributions and human phylogeographies. The potential role of refugia has frequently been acknowledged in the Late Pleistocene palaeoanthropological literature, yet explicit identification of potential refugia has been limited by the patchy nature of palaeoenvironmental and archaeological records, and the low temporal resolution of climate or ecological models. Here, we apply potential climatic thresholds on human habitation, rooted in ethnographic studies, in combination with high-resolution model datasets for precipitation and biome distributions to identify persistent refugia spanning the Late Pleistocene (130–10 ka). We present two alternate models suggesting that between 27% and 66% of Africa may have provided refugia to Late Pleistocene human populations, and examine variability in precipitation, biome and ecotone distributions within these refugial zones. This article is part of the theme issue ‘Tropical forests in the deep human past’

Technological and geometric morphometric analysis of ‘post-Howiesons Poort points’ from Border Cave, KwaZulu-Natal, South Africa

Lithic assemblages immediately following the Howiesons Poort, often loosely referred to as the ‘post-Howiesons Poort’ or MSA III, have attracted relatively little attention when compared to other well-known phases of the South African Middle Stone Age (MSA) sequence. Current evidence from sites occurring in widely-differing environments suggests that these assemblages are marked by temporal and technological variability, with few features in common other than the presence of unifacial points. Here we present a technological and geometric morphometric analysis of ‘points’ from the new excavations of Members 2 BS, 2 WA and the top of 3 BS members at Border Cave, KwaZulu-Natal, one of the key sites for studying modern human cultural evolution. Our complementary methodologies demonstrate that, at this site, hominins adopted a knapping strategy that primarily produced non-standardised unretouched points. Triangular morphologies were manufactured using a variety of reduction strategies, of which the discoidal and Levallois recurrent centripetal methods produced distinctive morphologies. We find technological and morphological variability increases throughout the post-Howiesons Poort sequence, with clear differences between and within chrono-stratigraphic groups. Finally, we assess the suitability of the ‘Sibudan’ cultural-technological typology proposed for post-Howiesons Poort assemblages at Sibhudu, another KwaZulu-Natal site, and find similarities in the morphological axes characterising the samples, despite differences in the shaping strategies adopted. Overall, our work contributes to the growing body of research that is helping to address historical research biases that have slanted our understanding of cultural evolution during the MSA of southern Africa towards the Still Bay and Howiesons Poort technocomplexes.publishedVersio

A spatiotemporally explicit paleoenvironmental framework for the Middle Stone Age of eastern Africa.

Eastern Africa has played a prominent role in debates about human evolution and dispersal due to the presence of rich archaeological, palaeoanthropological and palaeoenvironmental records. However, substantial disconnects occur between the spatial and temporal resolutions of these data that complicate their integration. Here, we apply high-resolution climatic simulations of two key parameters, mean annual temperature and precipitation, and a biome model, to produce a highly refined characterisation of the environments inhabited during the eastern African Middle Stone Age. Occupations are typically found in sub-humid climates and landscapes dominated by or including tropical xerophytic shrubland. Marked expansions from these core landscapes include movement into hotter, low-altitude landscapes in Marine Isotope Stage 5 and cooler, high-altitude landscapes in Marine Isotope Stage 3, with the recurrent inhabitation of ecotones between open and forested habitats. Through our use of high-resolution climate models, we demonstrate a significant independent relationship between past precipitation and patterns of Middle Stone Age stone tool production modes overlooked by previous studies. Engagement with these models not only enables spatiotemporally explicit examination of climatic variability across Middle Stone Age occupations in eastern Africa but enables clearer characterisation of the habitats early human populations were adapted to, and how they changed through time

A spatiotemporally explicit paleoenvironmental framework for the Middle Stone Age of eastern Africa.

Eastern Africa has played a prominent role in debates about human evolution and dispersal due to the presence of rich archaeological, palaeoanthropological and palaeoenvironmental records. However, substantial disconnects occur between the spatial and temporal resolutions of these data that complicate their integration. Here, we apply high-resolution climatic simulations of two key parameters, mean annual temperature and precipitation, and a biome model, to produce a highly refined characterisation of the environments inhabited during the eastern African Middle Stone Age. Occupations are typically found in sub-humid climates and landscapes dominated by or including tropical xerophytic shrubland. Marked expansions from these core landscapes include movement into hotter, low-altitude landscapes in Marine Isotope Stage 5 and cooler, high-altitude landscapes in Marine Isotope Stage 3, with the recurrent inhabitation of ecotones between open and forested habitats. Through our use of high-resolution climate models, we demonstrate a significant independent relationship between past precipitation and patterns of Middle Stone Age stone tool production modes overlooked by previous studies. Engagement with these models not only enables spatiotemporally explicit examination of climatic variability across Middle Stone Age occupations in eastern Africa but enables clearer characterisation of the habitats early human populations were adapted to, and how they changed through time