Effects of particle size, storage conditions, and chemical pretreatments on carbon and oxygen isotopic measurements of modern tooth enamel.

Isotopic analysis of human tooth enamel can provide life history information useful in forensic identification. These applications depend on the availability of reference data documenting isotopic values for individuals with known life history and on the comparability of data from reference and case work samples. Here we build on previous methodological research, which has largely focused on paleontological and archaeological samples, and conduct experiments using enamel from modern human teeth targeting three sample preparation variables (sample particle size, storage conditions, and chemical pretreatments). Our results suggest that differences in particle size affect the efficiency of sample reactions during pretreatment and analysis, with coarse particles giving reduced loss of enamel carbonate during acid pretreatments but producing slightly higher oxygen isotope values than fine particles during analysis. Data for samples stored in dry and ambient environments following pretreatment were indistinguishable, suggesting no exchange of oxygen between samples and ambient water vapor. Finally, chemical pretreatments with a range of commonly used reactants and conditions showed a pervasive, moderate oxygen isotope shift associated with acetic acid treatment, which may be caused by exchange of enamel hydroxyl groups with reagents or rinse waters. Collectively, the results emphasize the importance of methodological standardization to improve comparability and reduce potential for bias in the forensic application of tooth enamel isotope data.

The history of Coast Salish "woolly dogs" revealed by ancient genomics and Indigenous Knowledge.

Ancestral Coast Salish societies in the Pacific Northwest kept long-haired "woolly dogs" that were bred and cared for over millennia. However, the dog wool-weaving tradition declined during the 19th century, and the population was lost. In this study, we analyzed genomic and isotopic data from a preserved woolly dog pelt from "Mutton," collected in 1859. Mutton is the only known example of an Indigenous North American dog with dominant precolonial ancestry postdating the onset of settler colonialism. We identified candidate genetic variants potentially linked with their distinct woolly phenotype. We integrated these data with interviews from Coast Salish Elders, Knowledge Keepers, and weavers about shared traditional knowledge and memories surrounding woolly dogs, their importance within Coast Salish societies, and how colonial policies led directly to their disappearance.

Sidon on the breadth of the wild sea: Movement and diet on the Mediterranean coast in the Middle Bronze Age.

OBJECTIVES: Excavations at Sidon (Lebanon) have revealed dual identities during the Middle Bronze Age (ca. 2000-1600 BCE): a maritime port and center for local distribution, as well as a settlement with a heavy subsistence dependence on the extensive inland hinterlands. We aim to investigate residential mobility at Sidon using isotopic analyses of 112 individuals from 83 burials (20 females, 26 males, and 37 subadults). Veneration and remembrance of the dead is evident from funerary offerings in and near the tombs. With marine fish a major component in funerary offerings, we predict major marine reliance in this coastal population. MATERIALS AND METHODS: New isotopic evidence of paleomobility (87 Sr/86 Sr, δ18 O) and diet (δ13 Ccarbonate ) is the focus of this research. Previous bulk bone collagen δ13 C and δ15 N analysis is strengthened by further sampling, along with δ34 S where collagen yield was sufficient. RESULTS: The five non-locals identified (8.9% of the 56 analyzed) come from constructed tombs with high-status grave goods except for one, which was heavily disturbed in antiquity. Dietary investigation of the population confirms reliance on terrestrial resources with no significant marine input. No significant differences in diet between the sexes or burial types are present. CONCLUSIONS: Although Sidon was part of a growing Mediterranean network evidenced through artefactual finds, relatively low immigration is evident. While religious feasts venerating the dead may have involved significant piscine components, no appreciable marine input in diet is observed. Fish may have been reserved for the deceased or only consumed on feast days alongside the dead rather than a regular part of the Bronze Age menu.

Isotopic data for bioarchaeological samples from Polynesia (pre-Contact and modern periods).

Two datasets are presented in this paper, one from archaeologically-derived human remains and one from modern plants and animals. First, isotopic data (δ13C, δ15N, δ34S, and 87Sr/86Sr) along with some radiocarbon dates from archaeologically-derived bone and teeth from individuals buried in pre-Contact Tonga and Fiji are provided. The second dataset is comprised of modern plant and animal samples (n = 27) collected from the island of Atiu (Cook Islands). δ13C and δ15N data from these samples are presented, and this data is integrated with other datasets to provide an aggregated tropical Pacific dietary baseline for paleodietary studies in this region. First collected to explore the interactions between diet, mobility, social status, and the physical environment, the archaeologically-derived samples are from two Polynesian islands. From the Tongan island of Tongatapu, two burial mounds designated To-At-1 and To-At-2 and collectively called 'Atele, are radiocarbon dated to the Complex Centralized Chiefdom period (c. 500-150 BP). The second collection is from the coastal site of Bourewa in the Republic of Fiji, dated to the Vuda Phase (c. 750-150 BP). From these human remains the following tissues and isotopes were analyzed: bone and dentine collagen analysis of δ15N and δ13C (n = 81) as well as δ34S where collagen yield was large enough (n = 37), tooth enamel 87Sr/86Sr (n = 47), and radiocarbon dates to supplement the relative dating of the burial sites (n = 16). The human data provides a relatively large dataset (for the region) to compare to other contemporaneous sites to consider intra- and inter-island dietary practices and consider movement in the wider region (while being mindful of issues with interpretation). The amalgamated dietary baseline has utility for placing archaeological and ecological samples within the tropic Pacific foodweb.

Who were the Hyksos? Challenging traditional narratives using strontium isotope (87Sr/86Sr) analysis of human remains from ancient Egypt.

A foreign dynasty, known as the Hyksos, ruled parts of Egypt between c. 1638-1530 BCE. Their origins are thought to be rooted in the Near East, which is supported by architectural features and grave accoutrements of Tell el-Dabca. In this former Hyksos capital in the Eastern Nile Delta, burial culture is characterized by a blend of Egyptian and Near Eastern elements. However, investigations are still ongoing as to where the Hyksos came from and how they rose to power. The aim of this study is to elucidate the question of possible provenience. We present the results of strontium isotope (87Sr/86Sr) ratios of human tooth enamel (n = 75) from Tell el-Dabca, focusing on comparing pre- and during Hyksos rule and sex-based differences. An influx of non-locals can be observed in the pre-Hyksos period (12th and 13th Dynasties, c. 1991-1649 BCE) during the constitution of this important harbor town, while the number of individuals already born in the Delta is larger during the Hyksos period. This is consistent with the supposition that, while the ruling class had Near Eastern origins, the Hyksos' rise to power was not the result of an invasion, as popularly theorized, but an internal dominance and takeover of foreign elite. There is a preponderance of non-local females suggesting patrilocal residence. We discuss our findings against the current evidence of material culture and historiography, but more investigation in Near Eastern comparative sites has to be conducted to narrow our future search for the actual origins of the Hyksos.

Reconstructing breastfeeding and weaning practices in the Bronze Age Near East using stable nitrogen isotopes.

OBJECTIVES: Breastfeeding and childhood diet have significant impact on morbidity and mortality within a population, and in the ancient Near East, it is possible to compare bioarchaeological reconstruction of breastfeeding and weaning practices with the scant textual evidence. MATERIALS AND METHODS: Nitrogen stable isotopes (δ15 N) are analyzed here for dietary reconstruction in skeletal collections from five Bronze Age (ca. 2,800-1,200 BCE) sites in modern Lebanon and Syria. We employed Bayesian computational modeling on cross-sectional stable isotope data of collagen samples (n = 176) mainly from previous studies to test whether the bioarchaeological evidence aligns with the textual evidence of breastfeeding and weaning practices in the region, as well as compare the estimated weaning times to the global findings using the WARN (weaning age reconstruction with nitrogen isotope analysis) Bayesian model. RESULTS: Though the Near East sites in this study had different ecological settings and economic strategies, we found that weaning was introduced to the five sites at 0.5 ± 0.2 years of age and complete weaning occurred around 2.6 ± 0.3 years of age on using the WARN computational model. These weaning processes are within the time suggested by historical texts, though average estimated weaning age on the Mediterranean coast is later than inland sites. DISCUSSION: Compared globally, these Near Eastern populations initiated the weaning process earlier but completed weaning within the global average. Early initial weaning may have created short spacing between pregnancies and a high impact on demographic growth within these agricultural populations, with some variation in subsistence practices accounting for the inland/coastal discrepancies.