Elemental signatures of Australopithecus africanus teeth reveal seasonal dietary stress

Reconstructing the detailed dietary behaviour of extinct hominins is challenging1\u2014particularly for a species such as Australopithecus africanus, which has a highly variable dental morphology that suggests a broad diet2,3. The dietary responses of extinct hominins to seasonal fluctuations in food availability are poorly understood, and nursing behaviours even less so; most of the direct information currently available has been obtained from high-resolution trace-element geochemical analysis of Homo sapiens (both modern and fossil), Homo neanderthalensis4 and living apes5. Here we apply high-resolution trace-element analysis to two A. africanus specimens from Sterkfontein Member 4 (South Africa), dated to 2.6\u20132.1 million years ago. Elemental signals indicate that A. africanus infants predominantly consumed breast milk for the first year after birth. A cyclical elemental pattern observed following the nursing sequence\u2014comparable to the seasonal dietary signal that is seen in contemporary wild primates and other mammals\u2014indicates irregular food availability. These results are supported by isotopic evidence for a geographical range that was dominated by nutritionally depauperate areas. Cyclical accumulation of lithium in A. africanus teeth also corroborates the idea that their range was characterized by fluctuating resources, and that they possessed physiological adaptations to this instability. This study provides insights into the dietary cycles and ecological behaviours of A. africanus in response to food availability, including the potential cyclical resurgence of milk intake during times of nutritional challenge (as observed in modern wild orangutans5). The geochemical findings for these teeth reinforce the unique place of A. africanus in the fossil record, and indicate dietary stress in specimens that date to shortly before the extinction of Australopithecus in South Africa about two million years ago

Drimolen cranium DNH 155 documents microevolution in an early hominin species

Paranthropus robustus is a small-brained extinct hominin from South Africa characterized by derived, robust craniodental morphology. The most complete known skull of this species is DNH 7 from Drimolen Main Quarry, which differs from P. robustus specimens recovered elsewhere in ways attributed to sexual dimorphism. Here, we describe a new fossil specimen from Drimolen Main Quarry, dated from approximately 2.04–1.95 million years ago, that challenges this view. DNH 155 is a well-preserved adult male cranium that shares with DNH 7 a suite of primitive and derived features unlike those seen in adult P. robustus specimens from other chronologically younger deposits. This refutes existing hypotheses linking sexual dimorphism, ontogeny and social behaviour within this taxon, and clarifies hypotheses concerning hominin phylogeny. We document small-scale morphological changes in P. robustus associated with ecological change within a short time frame and restricted geography. This represents the most highly resolved evidence yet of microevolutionary change within an early hominin species

Human Remains from the Pleistocene-Holocene Transition of Southwest China Suggest a Complex Evolutionary History for East Asians

BACKGROUND: Later Pleistocene human evolution in East Asia remains poorly understood owing to a scarcity of well described, reliably classified and accurately dated fossils. Southwest China has been identified from genetic research as a hotspot of human diversity, containing ancient mtDNA and Y-DNA lineages, and has yielded a number of human remains thought to derive from Pleistocene deposits. We have prepared, reconstructed, described and dated a new partial skull from a consolidated sediment block collected in 1979 from the site of Longlin Cave (Guangxi Province). We also undertook new excavations at Maludong (Yunnan Province) to clarify the stratigraphy and dating of a large sample of mostly undescribed human remains from the site. METHODOLOGY/PRINCIPAL FINDINGS: We undertook a detailed comparison of cranial, including a virtual endocast for the Maludong calotte, mandibular and dental remains from these two localities. Both samples probably derive from the same population, exhibiting an unusual mixture of modern human traits, characters probably plesiomorphic for later Homo, and some unusual features. We dated charcoal with AMS radiocarbon dating and speleothem with the Uranium-series technique and the results show both samples to be from the Pleistocene-Holocene transition: ∼14.3-11.5 ka. CONCLUSIONS/SIGNIFICANCE: Our analysis suggests two plausible explanations for the morphology sampled at Longlin Cave and Maludong. First, it may represent a late-surviving archaic population, perhaps paralleling the situation seen in North Africa as indicated by remains from Dar-es-Soltane and Temara, and maybe also in southern China at Zhirendong. Alternatively, East Asia may have been colonised during multiple waves during the Pleistocene, with the Longlin-Maludong morphology possibly reflecting deep population substructure in Africa prior to modern humans dispersing into Eurasia

The spatial distribution of chacma baboon (Papio ursinus) habitat based on an environmental envelope

Abstract Predictive spatial modeling has become a key research tool for species distribution modeling where actual data are limited. Although qualitative maps and distribution descriptions for chacma baboons (Papio ursinus) are freely available, quantitative data are limited and do not provide the empirical information required to make informed decisions about issues such as population assessment, conservation, and management. Here we present the first quantitative, repeatable, and detailed predicted spatial distribution of the chacma baboon across southern Africa. Our distribution is at a finer level of detail than has previously been available. We used an environmental envelope model implemented within a geographic information system to achieve this. The model used environmental layers representing water availability, temperature and altitude, and model parameters determined from georeferenced observational data. The data extracted from the environmental layers suggest chacma baboons inhabit areas with mean minimum temperatures of the coolest month as low as −6.1°C, mean maximum temperatures of the warmest month as high as 38.2°C, mean annual rainfall up to 1,555 mm, and altitude up to 3,286 m. Our model demonstrates that the distribution of chacma baboons may be limited by temperature and rainfall, with the predicted northern extent of its range being temperature dependent. The model also implies that some areas well known for chacma baboon occupation today may in fact be marginal habitat. The resulting map highlights areas of suitable habitat in southern Africa. In addition, a linear "patchy" corridor was identified following the East African Rift Valley connecting Int J Primato

At the heart of the African Acheulean: the physical, social and cognitive landscapes of Kilombe

Kilombe is known as an extensive late Lower Pleistocene Acheulean site complex in the Rift Valley in Kenya. We report here on recent research which has explored a longer stratigraphic succession around the sites, casting light on landscape development and occupation through much of the last million years. With its position near the Equator the site complex is close to the geographic and chronological heart of the Acheulean, and ideally suited to investigations, because of the extent of preservation of ancient landscape, and the potential for dating and recovery of environmental information The new surveys have concentrated on studying the site area in its local setting near the foot of Kilombe volcano, which became extinct in the early Pleistocene, and formerly held a crater lake, currently under investigation. In 2011, bifaces were also found at the mouth of the volcano gorge. Events on the Acheulean main site terminated with a volcanic eruption which deposited the 3-banded tuff (3BT), now dated to ca. 990,000 years, but the sequence continues above this level, and is capped locally by an ashflow tuff (AFT) some 7 metres thick, the product of a landscape-transforming eruption probably deriving from an ancestor of the present day Menengai. To the east and west, the sequence then resumes with major exposures of tuffaceous sediments belonging to the Middle and Upper Pleistocene, and containing Middle Stone Age and Later Stone Age artefacts. These provide the chance to study newer landscapes within the same catchment. The Kilombe main site permits very rare opportunities to compare large numbers of bifaces and other artefacts which are of the same age across a distance of around 200 metres, and so build up a picture of local variability within a site complex. The site area allows comparisons – within the complex to explore its structure of variation, on a regional scale of site catchment, and then externally to help evaluate issues across the greater Acheulean world and through the Middle Stone Age. Although the development of the MSA can be seen only sketchily at present, the preservation of both contexts and artefacts demonstrates the potential to elaborate a longer record

Environmental conditions in the SE Balkans since the Last Glacial Maximum and their influence on the spread of agriculture into Europe

The Thracian Plain in the SE Balkans was one of the main corridors through which Neolithic agriculture spread into continental Europe. Previous studies have invoked rapid sea-level and climatic changes to explain the timing of agricultural expansion. We present a new record of vegetation, fire and lacustrine sedimentation from Bulgarian Thrace to examine environmental change in this region since the Last Glacial Maximum. Our record indicates the persistence of cold steppe vegetation from ∼37,500 to 17,900 cal. a BP, semidesert vegetation from ∼17,900 to 10,300 cal. a BP, forest-steppe vegetation from ∼10,300 to 8900 cal. a BP, and mixed oak woods from ∼8900 to 4000 cal. a BP, followed by widespread deforestation, burning and grazing. Early-Holocene forest expansion in Bulgarian Thrace closely followed changes in the Black Sea's regional moisture balance and appears to have been influenced by solar-forced changes in seasonality. We suggest that climatic aridity and/or enhanced seasonality - lasting until at least ∼8900 cal. a BP - could have delayed the spread of early agriculture from the Aegean coast into the continental lowlands of the Balkans and thence into the rest of Europe.16 page(s

Elemental signatures of Australopithecus africanus teeth reveal seasonal dietary stress

Reconstructing the detailed dietary behaviour of extinct hominins is challenging1—particularly for a species such as Australopithecus africanus, which has a highly variable dental morphology that suggests a broad diet2,3. The dietary responses of extinct hominins to seasonal fluctuations in food availability are poorly understood, and nursing behaviours even less so; most of the direct information currently available has been obtained from high-resolution trace-element geochemical analysis of Homo sapiens (both modern and fossil), Homo neanderthalensis4 and living apes5. Here we apply high-resolution trace-element analysis to two A. africanus specimens from Sterkfontein Member 4 (South Africa), dated to 2.6–2.1 million years ago. Elemental signals indicate that A. africanus infants predominantly consumed breast milk for the first year after birth. A cyclical elemental pattern observed following the nursing sequence—comparable to the seasonal dietary signal that is seen in contemporary wild primates and other mammals—indicates irregular food availability. These results are supported by isotopic evidence for a geographical range that was dominated by nutritionally depauperate areas. Cyclical accumulation of lithium in A. africanus teeth also corroborates the idea that their range was characterized by fluctuating resources, and that they possessed physiological adaptations to this instability. This study provides insights into the dietary cycles and ecological behaviours of A. africanus in response to food availability, including the potential cyclical resurgence of milk intake during times of nutritional challenge (as observed in modern wild orangutans5). The geochemical findings for these teeth reinforce the unique place of A. africanus in the fossil record, and indicate dietary stress in specimens that date to shortly before the extinction of Australopithecus in South Africa about two million years ago

Drimolen cranium DNH 155 documents microevolution in an early hominin species

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First hominine remains from a ~1.0 million year old bone bed at Cornelia-Uitzoek, Free State Province, South Africa

We report here on evidence of early . Homo around 1.0 Ma (millions of years ago) in the central plains of southern Africa. The human material, a first upper molar, was discovered during the systematic excavation of a densely-packed bone bed in the basal part of the sedimentary sequence at the Cornelia-Uitzoek fossil vertebrate locality. We dated this sequence by palaeomagnetism and correlated the bone bed to the Jaramillo subchron, between 1.07 and 0.99 Ma. This makes the specimen the oldest southern African hominine remains outside the dolomitic karst landscapes of northern South Africa. Cornelia-Uitzoek is the type locality of the Cornelian Land Mammal Age. The fauna contains an archaic component, reflecting previous biogeographic links with East Africa, and a derived component, suggesting incipient southern endemism. The bone bed is considered to be the result of the bone collecting behaviour of a large predator, possibly spotted hyaenas. Acheulian artefacts are found in small numbers within the bone bed among the fossil vertebrates, reflecting the penecontemporaneous presence of people in the immediate vicinity of the occurrence. The hominine tooth was recovered from the central, deeper part of the bone bed. In size, it clusters with southern African early . Homo and it is also morphologically similar. We propose that the early . Homo specimen forms part of an archaic component in the fauna, in parallel with the other archaic faunal elements at Uitzoek. This supports an emergent pattern of archaic survivors in the southern landscape at this time, but also demonstrates the presence of early . Homo in the central plains of southern Africa, beyond the dolomitic karst areas