Age-dependent change and intraskeletal variability in secondary osteons of elderly Australians.

There is a need to fully understand intra-skeletal variability within different populations to develop and improve age-at-death estimation methods. This study evaluates age-related histomorphometric changes in three different bones intra-individually in a modern Australian sample. Four female and 13 male elderly Australian adult donors (67-93 years) were examined for osteon population density (OPD), osteon area (On.Ar), and Haversian canal area (H.Ar) of secondary osteons to compare between femora, ribs, and humeri and assess against age. In the pooled sex sample, no statistically significant correlations were observed between age and each histological variable. In the males, OPD of the femur increased significantly with age, as did porosity in the rib. In the male humeri, OPD increased moderately with age, while H.Ar was decreased moderately with age. Intra-bone comparisons showed that males had significantly higher osteon counts in their ribs compared to their femora, while their ribs showed statistically significantly less porosity than their humeri. When bone size was accounted for, by adjusting the femur and humerus histology data by robusticity indices, histology values were found to be similar between bones within the same individual. This is despite the upper and lower limbs receiving different ranges and types of biomechanical load. Our findings demonstrate that bone size influences histomorphometry, and this could confound age-at-death estimations that have not been adjusted for robusticity. Future studies would benefit from examining bone histomorphometry within a larger sample size and incorporating bone robusticity measures into histology analyses.

Paleoepidemiology of cribra orbitalia: Insights from early seventh millennium BP Con Co Ngua, Vietnam.

OBJECTIVES: We test the hypothesis that the condition(s) leading to the development of cribra orbitalia at Con Co Ngua, an early seventh millennium sedentary foraging community in Vietnam, effectively reduced the resilience of the population to subsequent health/disease impacts. An assessment of both the implications and potential etiology of cribra orbitalia in this specific population is carried out. METHODS: The effective sample included 141 adults aged ≥15 years (53 females, 71 males, and 17 unknown sex) and 15 pre-adults aged ≤14 years. Cribra orbitalia was identified by way of cortical bone porosity of the orbital roof initiated within the diplöic space, rather than initiated subperiosteally. The approach is also robust to the misidentification of various pseudo-lesions. Resultant data was analyzed using Kaplan-Meier survival analysis. RESULTS: Median survival is higher in adults aged ≥15 years without cribra orbitalia than those with this lesion. For the pre-adult cohort, the opposite pattern is seen where median survival is higher in those with cribra orbitalia than those without. CONCLUSION: Adults displayed increased frailty and pre-adults increased resilience with respect to cribra orbitalia. The differential diagnosis for a survival analysis of adults and pre-adults with and without cribra orbitalia included iron deficiency anemia and B12/folate deficiency, parasitism (including hydatid disease and malaria) in addition to thalassemia. The most parsimonious explanation for observed results is for both thalassemia and malaria being the chief etiological agents, while appreciating these conditions interact with, and can cause, other forms such as hematinic deficiency anemias.

Hydatid disease (Echinococcosis granulosis) diagnosis from skeletal osteolytic lesions in an early seventh-millennium BP forager community from preagricultural northern Vietnam.

OBJECTIVES: Con Co Ngua is a complex, sedentary forager site from northern Vietnam dating to the early seventh millennium BP. Prior research identified a calcified Echinococcus granulosis cyst, which causes hydatid disease. Osteolytic lesions consistent with hydatid disease were also present in this individual and others. Hydatid disease is observed in high frequencies in pastoralists, and its presence in a hunter-gatherer community raises questions regarding human-animal interaction prior to farming. The objective of this article is to identify and describe the epidemiology of hydatid disease in the human skeletal assemblage at Con Co Ngua. MATERIALS AND METHODS: One hundred and fifty-five individuals were macroscopically assessed for lesions. Of these, eight individuals were radiographed. Hydatid disease was diagnosed using a new threshold criteria protocol derived from clinical literature, which prioritizes lesions specific to the parasite. RESULTS: Twenty-two individuals (14.2%) presented with osteolytic lesions consistent with hydatid disease, affecting the distal humerus, proximal femur and forearm, and pelvis. Seven individuals radiographed (4.5%) had multilocular cystic lesions strongly diagnostic for hydatid disease. All probable cases had lesions of the distal humerus. The remaining lesions were macroscopically identical to those radiographed and were considered possible cases. DISCUSSION: While hydatid disease has previously been found in pre-agricultural communities, the high prevalence at Con Co Ngua is non-incidental. We propose that the presence of wild canids and management of wild buffalo and deer increased the risk of disease transmission. These findings further reveal subsistence complexity among hunter-gatherers living millennia prior to the adoption of farming in Southeast Asia.

Forager and farmer evolutionary adaptations to malaria evidenced by 7000 years of thalassemia in Southeast Asia.

Thalassemias are inherited blood disorders that are found in high prevalences in the Mediterranean, Southeast Asia and the Pacific. These diseases provide varying levels of resistance to malaria and are proposed to have emerged as an adaptive response to malaria in these regions. The transition to agriculture in the Holocene has been suggested to have influenced the selection for thalassemia in the Mediterranean as land clearance for farming encouraged interaction between Anopheles mosquitos, the vectors for malaria, and human groups. Here we document macroscopic and microscopic skeletal evidence for the presence of thalassemia in both hunter-gatherer (Con Co Ngua) and early agricultural (Man Bac) populations in northern Vietnam. Firstly, our findings demonstrate that thalassemia emerged prior to the transition to agriculture in Mainland Southeast Asia, from at least the early seventh millennium BP, contradicting a long-held assumption that agriculture was the main driver for an increase in malaria in Southeast Asia. Secondly, we describe evidence for significant malarial burden in the region during early agriculture. We argue that the introduction of farming into the region was not the initial driver of the selection for thalassemia, as it may have been in other regions of the world.

Dating the megalithic culture of laos: Radiocarbon, optically stimulated luminescence and U/Pb zircon results.

The megalithic jar sites of Laos (often referred to as the Plain of Jars) remain one of Southeast Asia's most mysterious and least understood archaeological cultures. The sites, recently inscribed as UNESCO World Heritage, host hollowed stone jars, up to three metres in height, which appear scattered across the landscape, alone or clustered in groups of up to more than 400. Until now, it has not been possible to estimate when the jars were first placed on the landscape or from where the stone was sourced. Geochronological analysis using the age of detrital zircons demonstrates a likely quarry source for one of the largest megalithic jar sites. Optically Stimulated Luminescence (OSL) dating suggests the jars were positioned at the sites potentially as early as the late second millennium BC. Radiocarbon dating of skeletal remains and charcoal samples places mortuary activity around the jars from the 9-13th century AD, suggesting the sites have maintained ritual significance from the period of their initial placement until historic times.

Domestication and large animal interactions: Skeletal trauma in northern Vietnam during the hunter-gatherer Da But period.

The aim of this paper is to test the hypothesis that healed traumatic injuries in the pre-Neolithic assemblage of Con Co Ngua, northern Vietnam (c. 6800-6200 cal BP) are consistent with large wild animal interactions prior to their domestication. The core sample included 110 adult (aged ≥ 18 years) individuals, while comparisons are made with an additional six skeletal series from Neolithic through to Iron Age Vietnam, Thailand, and Mongolia. All post cranial skeletal elements were assessed for signs of healed trauma and identified cases were further x-rayed. Crude trauma prevalence (14/110, 12.7%) was not significantly different between males (8/52) and females (5/37) (χ2 = 0.061, p = 0.805). Nor were there significant differences in the prevalence of fractured limbs, although males displayed greater rates of lower limb bone trauma than females. Further, distinct from females, half the injured males suffered vertebral fractures, consistent with high-energy trauma. The first hypothesis is supported, while some support for the sexual divisions of labour was found. The prevalence and pattern of fractured limbs at CCN when compared with other Southeast and East Asian sites is most similar to the agropastoral site of Lamadong, China. The potential for skeletal trauma to assess animal trapping and herding practices prior to domestication in the past is discussed.

Author Correction: Craniometrics Reveal "Two Layers" of Prehistoric Human Dispersal in Eastern Eurasia.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Craniometrics Reveal "Two Layers" of Prehistoric Human Dispersal in Eastern Eurasia.

This cranio-morphometric study emphasizes a "two-layer model" for eastern Eurasian anatomically modern human (AMH) populations, based on large datasets of 89 population samples including findings directly from ancient archaeological contexts. Results suggest that an initial "first layer" of AMH had related closely to ancestral Andaman, Australian, Papuan, and Jomon groups who likely entered this region via the Southeast Asian landmass, prior to 65-50 kya. A later "second layer" shared strong cranial affinities with Siberians, implying a Northeast Asian source, evidenced by 9 kya in central China and then followed by expansions of descendant groups into Southeast Asia after 4 kya. These two populations shared limited initial exchange, and the second layer grew at a faster rate and in greater numbers, linked with contexts of farming that may have supported increased population densities. Clear dichotomization between the two layers implies a temporally deep divergence of distinct migration routes for AMH through both southern and northern Eurasia.

Ancient genomes document multiple waves of migration in Southeast Asian prehistory.

Southeast Asia is home to rich human genetic and linguistic diversity, but the details of past population movements in the region are not well known. Here, we report genome-wide ancient DNA data from 18 Southeast Asian individuals spanning from the Neolithic period through the Iron Age (4100 to 1700 years ago). Early farmers from Man Bac in Vietnam exhibit a mixture of East Asian (southern Chinese agriculturalist) and deeply diverged eastern Eurasian (hunter-gatherer) ancestry characteristic of Austroasiatic speakers, with similar ancestry as far south as Indonesia providing evidence for an expansive initial spread of Austroasiatic languages. By the Bronze Age, in a parallel pattern to Europe, sites in Vietnam and Myanmar show close connections to present-day majority groups, reflecting substantial additional influxes of migrants.