Rock art and frontier conflict in Southeast Asia: Insights from direct radiocarbon ages for the large human figures of Gua Sireh, Sarawak.

Gua Sireh, located in western Sarawak (Malaysian Borneo), is known for its rock art. The cave houses hundreds of charcoal drawings depicting people, often with headdresses, knives and other accoutrements. Here, we present direct radiocarbon dates and pigment characterizations from charcoal drawings of two large (>75 cm), unique Gua Sireh human figures (anthropomorphs). To our knowledge, these are the first chronometric ages generated for Malaysian rock art, providing insights into the social contexts of art production, as well as the opportunities and challenges of dating rock art associated with the Malay/Austronesian diasporas in Southeast Asia more generally. Previous archaeological excavations revealed that people occupied Gua Sireh from around 20,000 years ago to as recently as AD 1900. The site is within Bidayuh territory, and these local Indigenous peoples recall the cave's use as a refuge during territorial violence in the early 1800s. The age of the drawings, dated between 280 and 120 cal BP (AD 1670 to 1830), corresponds with a period of increasing conflict when the Malay elites controlling the region exacted heavy tolls on the local hill tribes. We discuss rock art production at Gua Sireh in this context of frontier conflict and Bidayuh resistance.

Analysis of the Preserved Amino Acid Bias in Peptide Profiles of Iron Age Teeth from a Tropical Environment Enable Sexing of Individuals Using Amelogenin MRM.

The first dental proteomic profile of Iron Age individuals (ca. 2000-1000 years B.P.), collected from the site of Long Long Rak rock shelter in northwest Thailand is described. A bias toward the preservation of the positively charged aromatic, and polar amino acids is observed. It is evident that the 212 proteins identified (2 peptide, FDR <1%) comprise a palimpsest of alterations that occurred both ante-mortem and post-mortem. Conservation of amino acids within the taphonomically resistant crystalline matrix enabled the identification of both X and Y chromosome linked amelogenin peptides. A novel multiple reaction monitoring method using the sex specific amelogenin protein isoforms is described and indicate the teeth are of male origin. Functional analysis shows an enrichment of pathways associated with metabolic disorders and shows a capacity for harboring these conditions prior to death. Stable isotope analysis using carbon isotopes highlights the strongly C3 based (≈80%) diet of the Long Long Rak cemetery people, which probably comprised rice combined with protein from freshwater fish among other food items. The combination of proteomics and stable isotope analysis provides a complementary strategy for assessing the demography, diet, lifestyle, and possible diseases experienced by ancient populations.

Ancient nuclear genomes enable repatriation of Indigenous human remains.

After European colonization, the ancestral remains of Indigenous people were often collected for scientific research or display in museum collections. For many decades, Indigenous people, including Native Americans and Aboriginal Australians, have fought for their return. However, many of these remains have no recorded provenance, making their repatriation very difficult or impossible. To determine whether DNA-based methods could resolve this important problem, we sequenced 10 nuclear genomes and 27 mitogenomes from ancient pre-European Aboriginal Australians (up to 1540 years before the present) of known provenance and compared them to 100 high-coverage contemporary Aboriginal Australian genomes, also of known provenance. We report substantial ancient population structure showing strong genetic affinities between ancient and contemporary Aboriginal Australian individuals from the same geographic location. Our findings demonstrate the feasibility of successfully identifying the origins of unprovenanced ancestral remains using genomic methods.

Rare Late Pleistocene-early Holocene human mandibles from the Niah Caves (Sarawak, Borneo).

The skeletal remains of Late Pleistocene-early Holocene humans are exceptionally rare in island Southeast Asia. As a result, the identity and physical adaptations of the early inhabitants of the region are poorly known. One archaeological locality that has historically been important for understanding the peopling of island Southeast Asia is the Niah Caves in the northeast of Borneo. Here we present the results of direct Uranium-series dating and the first published descriptions of three partial human mandibles from the West Mouth of the Niah Caves recovered during excavations by the Harrissons in 1957. One of them (mandible E/B1 100") is somewhat younger than the 'Deep Skull' with a best dating estimate of c30-28 ka (at 2σ), while the other two mandibles (D/N5 42-48" and E/W 33 24-36") are dated to a minimum of c11.0-10.5 ka (at 2σ) and c10.0-9.0 ka (at 2σ). Jaw E/B1 100" is unusually small and robust compared with other Late Pleistocene mandibles suggesting that it may have been ontogenetically altered through masticatory strain under a model of phenotypic plasticity. Possible dietary causes could include the consumption of tough or dried meats or palm plants, behaviours which have been documented previously in the archaeological record of the Niah Caves. Our work suggests a long history back to before the LGM of economic strategies involving the exploitation of raw plant foods or perhaps dried and stored meat resources. This offers new insights into the economic strategies of Late Pleistocene-early Holocene hunter-gatherers living in, or adjacent to, tropical rainforests.

A Hominin Femur with Archaic Affinities from the Late Pleistocene of Southwest China.

The number of Late Pleistocene hominin species and the timing of their extinction are issues receiving renewed attention following genomic evidence for interbreeding between the ancestors of some living humans and archaic taxa. Yet, major gaps in the fossil record and uncertainties surrounding the age of key fossils have meant that these questions remain poorly understood. Here we describe and compare a highly unusual femur from Late Pleistocene sediments at Maludong (Yunnan), Southwest China, recovered along with cranial remains that exhibit a mixture of anatomically modern human and archaic traits. Our studies show that the Maludong femur has affinities to archaic hominins, especially Lower Pleistocene femora. However, the scarcity of later Middle and Late Pleistocene archaic remains in East Asia makes an assessment of systematically relevant character states difficult, warranting caution in assigning the specimen to a species at this time. The Maludong fossil probably samples an archaic population that survived until around 14,000 years ago in the biogeographically complex region of Southwest China.

Possible Signatures of Hominin Hybridization from the Early Holocene of Southwest China.

We have previously described hominin remains with numerous archaic traits from two localities (Maludong and Longlin Cave) in Southwest China dating to the Pleistocene-Holocene transition. If correct, this finding has important implications for understanding the late phases of human evolution. Alternative interpretations have suggested these fossils instead fit within the normal range of variation for early modern humans in East Asia. Here we test this proposition, consider the role of size-shape scaling, and more broadly assess the affinities of the Longlin 1 (LL1) cranium by comparing it to modern human and archaic hominin crania. The shape of LL1 is found to be highly unusual, but on balance shows strongest affinities to early modern humans, lacking obvious similarities to early East Asians specifically. We conclude that a scenario of hybridization with archaic hominins best explains the highly unusual morphology of LL1, possibly even occurring as late as the early Holocene.

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.