27 research outputs found
Old stones’ song—second verse: use-wear analysis of rhyolite and fenetized andesite artifacts from the Oldowan lithic industry of Kanjera South, Kenya
This paper investigates Oldowan hominin behavioral ecology through use-wear analysis of artifacts from Kanjera South, Western Kenya. It extends development of our experimental use-wear reference collection and analysis of use-wear on the well preserved and unweathered Oldowan tools from this site to include rhyolite, a non-local material of similar durability to previously studied quartz and quartzite tools, and fenetized andesite, a local material with considerably less durability. Variability in rhyolite and fenetized andesite texture, inclusions, and matrix required enhancement of previous methods so we combine the use of stereoscopic, metallographic, and scanning electron microscopy in this study. This study allows us to begin exploration of the links between specific artifactual raw materials and the materials they were used to process. Data assembled so far suggest that tools fashioned from non-local and local stone were, with one possible exception, used to process similar materials. Additionally, experiments carried out with replicas of tools made of rhyolite and fenetized andesite confirm interpretation of reduction sequences that tools made of less durable local material had a shorter use-life and were used expediently compared to the more durable non-local quartz, quartzite, and rhyolite. These new data improve our understanding, of the functional needs, behavioral solutions, and cognitive capacities of Oldowan hominins. Finally, these data show how use-wear analysis, combined with lithic raw material and lithic technology, can be a powerful means for evaluating two key points for human evolution: long-term memory, and planning
Oldest evidence of tool making hominins in a grassland-dominated ecosystem.
BACKGROUND: Major biological and cultural innovations in late Pliocene hominin evolution are frequently linked to the spread or fluctuating presence of C(4) grass in African ecosystems. Whereas the deep sea record of global climatic change provides indirect evidence for an increase in C(4) vegetation with a shift towards a cooler, drier and more variable global climatic regime beginning approximately 3 million years ago (Ma), evidence for grassland-dominated ecosystems in continental Africa and hominin activities within such ecosystems have been lacking. METHODOLOGY/PRINCIPAL FINDINGS: We report stable isotopic analyses of pedogenic carbonates and ungulate enamel, as well as faunal data from approximately 2.0 Ma archeological occurrences at Kanjera South, Kenya. These document repeated hominin activities within a grassland-dominated ecosystem. CONCLUSIONS/SIGNIFICANCE: These data demonstrate what hitherto had been speculated based on indirect evidence: that grassland-dominated ecosystems did in fact exist during the Plio-Pleistocene, and that early Homo was active in open settings. Comparison with other Oldowan occurrences indicates that by 2.0 Ma hominins, almost certainly of the genus Homo, used a broad spectrum of habitats in East Africa, from open grassland to riparian forest. This strongly contrasts with the habitat usage of Australopithecus, and may signal an important shift in hominin landscape usage
Expanded geographic distribution and dietary strategies of the earliest Oldowan hominins and Paranthropus
The oldest Oldowan tool sites, ca. 2.6 million years ago (Ma), have previously been confined to Ethiopia’s Afar Triangle. We describe sites at Nyayanga, Kenya, dated to 3.032-2.581 Ma, and expand this distribution by over 1300 km. Furthermore, we found two hippopotamid butchery sites associated with mosaic vegetation and a C4 grazer-dominated fauna. Tool flaking proficiency was comparable to younger Oldowan assemblages, but pounding activities were more common. Tool use-wear and bone damage indicate plant and animal tissue processing. Paranthropus sp. teeth, the first from southwestern Kenya, possessed carbon isotopic values indicative of a diet rich in C4 foods. We argue that the earliest Oldowan was more widespread than previously known, used to process diverse foods including megafauna, and associated with Paranthropus from its onset
Biomolecular insights into North African-related ancestry, mobility and diet in eleventh-century Al-Andalus
Historical records document medieval immigration from North Africa to Iberia to create Islamic al-Andalus. Here, we present a low-coverage genome of an eleventh century CE man buried in an Islamic necropolis in Segorbe, near Valencia, Spain. Uniparental lineages indicate North African ancestry, but at the autosomal level he displays a mosaic of North African and European-like ancestries, distinct from any present-day population. Altogether, the genome-wide evidence, stable isotope results and the age of the burial indicate that his ancestry was ultimately a result of admixture between recently arrived Amazigh people (Berbers) and the population inhabiting the Peninsula prior to the Islamic conquest. We detect differences between our sample and a previously published group of contemporary individuals from Valencia, exemplifying how detailed, small-scale aDNA studies can illuminate fine-grained regional and temporal differences. His genome demonstrates how ancient DNA studies can capture portraits of past genetic variation that have been erased by later demographic shifts—in this case, most likely the seventeenth century CE expulsion of formerly Islamic communities as tolerance dissipated following the Reconquista by the Catholic kingdoms of the north
Diagenesis of the Baynunah, Shuwaihat and Upper Dam Formation Sediments exposed in the western region of Abu Dhabi
Paleolandscape variation in early Pleicstocene Hominid activities: Members 1 and 7, Olorgesailie Formation, Kenya
Current research on the Plio-Pleistocene deposits north of Homa Mountain, southwestern Kenya
The life-history of a late Mesolithic woman in Iberia: A sequential multi-isotope approach
Multi-isotope analyses on diverse body tissues can offer valuable information on individual life-histories at different temporal resolutions. Here, we reconstruct the diet and mobility of a Late Mesolithic (ca. 5500 cal. BC) young woman buried in Aizpea rockshelter (Navarre, north-central Iberia). To this end, we combine δ13C and δ15N isotope analyses of bone collagen, together with sequential δ13C and δ15N isotope analyses of tooth dentine and 87Sr/86Sr analysis of tooth enamel from the permanent maxillary right second molar. We also present results of bone collagen measurements for a wide range of coeval faunal remains, including terrestrial ungulates, freshwater fish and birds, and plant remains (i.e. carbonized pome fruits and hazelnut shells) to characterize baseline isotopic signatures. Results suggest a broad-spectrum diet with a relatively high and stable protein intake during early childhood and significant changes in diet during late childhood, including two marked dips in δ15N at 8.5 and 11.5 years old, and a progressive decrease in δ13C and δ15N from adolescence onwards. The dips may relate to metabolic processes related to growth or, more probably, to age-related subsistence practices, particularly supplementation by children of the parentally provisioned diet, while the sustained drop in isotope values may be associated with a progressively higher dietary contribution from plants that extends into adulthood. Strontium isotope data support relatively restricted mobility from age 2.5 to 8 (i.e. the approximate time-span covered by enamel formation in the permanent maxillary second molar), consistent with the high degree of territoriality attributed to the last hunters-gatherers in northern Iberia