Yvette Eley

Ancient lipids document continuity in the use of early hunter-gatherer pottery through 9,000 years of Japanese prehistory.

Significance Pottery has had a central role in human society for many millennia, but the reasons for the emergence and spread of this technology are poorly understood. First invented by groups of hunter–gatherers living in East Asia during the last glacial period, production only began to flourish with rising global temperatures in the Holocene, but the reasons for its uptake and spread are unknown. Through chemical analysis of their contents, we herein provide, to our knowledge, the first direct evidence of pottery use across this climatic transition. Contrary to expectations, ceramic vessels had a remarkably consistent use, predominantly for processing aquatic resources, indicating that cultural rather than environmental factors were most important for their widespread uptake. The earliest pots in the world are from East Asia and date to the Late Pleistocene. However, ceramic vessels were only produced in large numbers during the warmer and more stable climatic conditions of the Holocene. It has long been assumed that the expansion of pottery was linked with increased sedentism and exploitation of new resources that became available with the ameliorated climate, but this hypothesis has never been tested. Through chemical analysis of their contents, we herein investigate the use of pottery across an exceptionally long 9,000-y sequence from the Jōmon site of Torihama in western Japan, intermittently occupied from the Late Pleistocene to the mid-Holocene. Molecular and isotopic analyses of lipids from 143 vessels provides clear evidence that pottery across this sequence was predominantly used for cooking marine and freshwater resources, with evidence for diversification in the range of aquatic products processed during the Holocene. Conversely, there is little indication that ruminant animals or plants were processed in pottery, although it is evident from the faunal and macrobotanical remains that these foods were heavily exploited. Supported by other residue analysis data from Japan, our results show that the link between pottery and fishing was established in the Late Paleolithic and lasted well into the Holocene, despite environmental and socio-economic change. Cooking aquatic products in pottery represents an enduring social aspect of East Asian hunter–gatherers, a tradition based on a dependable technology for exploiting a sustainable resource in an uncertain and changing world.

First molecular and isotopic evidence of millet processing in prehistoric pottery vessels

Analysis of organic residues in pottery vessels has been successful in detecting a range of animal and plant products as indicators of food preparation and consumption in the past. However, the identification of plant remains, especially grain crops in pottery, has proved elusive. Extending the spectrum is highly desirable, not only to strengthen our understanding of the dispersal of crops from centres of domestication but also to determine modes of food processing, artefact function and the culinary significance of the crop. Here, we propose a new approach to identify millet in pottery vessels, a crop that spread throughout much of Eurasia during prehistory following its domestication, most likely in northern China. We report the successful identification of miliacin (olean-18-en-3β-ol methyl ether), a pentacyclic triterpene methyl ether that is enriched in grains of common/broomcorn millet (Panicum miliaceum), in Bronze Age pottery vessels from the Korean Peninsula and northern Europe. The presence of millet is supported by enriched carbon stable isotope values of bulk charred organic matter sampled from pottery vessel surfaces and extracted n-alkanoic acids, consistent with a C4 plant origin. These data represent the first identification of millet in archaeological ceramic vessels, providing a means to track the introduction, spread and consumption of this important crop.

Reconstructing vapor pressure deficit from leaf wax lipid molecular distributions

Estimates of atmospheric moisture are critical for understanding the links and feedbacks between atmospheric CO2 and global climate. At present, there are few quantitative moisture proxies that are applicable to deep time. We present a new proxy for atmospheric moisture derived from modern climate and leaf biomarker data from North and Central America. Plants have a direct genetic pathway to regulate the production of lipids in response to osmotic stress, which is manifested in a change in the distribution of simple aliphatic lipids such as n-alkanes. The Average Chain Length (ACL) of these lipids is therefore statistically related to mean annual vapor pressure deficit (VPDav), enabling quantitative reconstruction of VPD from sedimentary n-alkanes. We apply this transfer function to the Armantes sectionxa0of the Calatayud-Daroca Basin inxa0Central Spain, that spans the Middle Miocene Climatic Optimum (MMCO) and the Middle Miocene Climate Transition (MMCT). Reconstructed VPDav rises from 0.13 to 0.92u2009kPa between 16.5 and 12.4u2009Ma, indicating a substantial drying through the MMCT. These data are consistent with fossil assemblages and mammalian stable isotope data, highlighting the utility of this new organic molecular tool for quantifying hydrologic variability over geologic timescales.

The impact of environmental change on the use of early pottery by East Asian hunter-gatherers

Significance The motivations for the widespread adoption of pottery is a key theme in world prehistory and is often linked to climate warming at the start of the Holocene. Through organic residue analysis, we investigated the contents of >800 ceramic samples from across the Japanese archipelago, a unique assemblage that transcends the Pleistocene–Holocene boundary. Against our expectations, we found that pottery use did not fundamentally change in the Early Holocene. Instead, aquatic resources dominated in both periods regardless of the environmental setting. Nevertheless, we found that a broader range of aquatic foods was processed in Early Holocene vessels, corresponding to increased ceramic production, reduced mobility, intensified fishing, and the start of significant shellfish gathering at this time. The invention of pottery was a fundamental technological advancement with far-reaching economic and cultural consequences. Pottery containers first emerged in East Asia during the Late Pleistocene in a wide range of environmental settings, but became particularly prominent and much more widely dispersed after climatic warming at the start of the Holocene. Some archaeologists argue that this increasing usage was driven by environmental factors, as warmer climates would have generated a wider range of terrestrial plant and animal resources that required processing in pottery. However, this hypothesis has never been directly tested. Here, in one of the largest studies of its kind, we conducted organic residue analysis of >800 pottery vessels selected from 46 Late Pleistocene and Early Holocene sites located across the Japanese archipelago to identify their contents. Our results demonstrate that pottery had a strong association with the processing of aquatic resources, irrespective of the ecological setting. Contrary to expectations, this association remained stable even after the onset of Holocene warming, including in more southerly areas, where expanding forests provided new opportunities for hunting and gathering. Nevertheless, the results indicate that a broader array of aquatic resources was processed in pottery after the start of the Holocene. We suggest this marks a significant change in the role of pottery of hunter-gatherers, corresponding to an increased volume of production, greater variation in forms and sizes, the rise of intensified fishing, the onset of shellfish exploitation, and reduced residential mobility.

Variation in Hydrogen Isotope Composition Among Salt Marsh Plant Organic Compounds Highlights Biochemical Mechanisms Controlling Biosynthetic Fractionation

Hydrogen isotopes of plant‐derived biomarkers can vary by >100‰ at a single location. Isotope fractionation associated with the movement of water in plant leaves cannot account for this variability alone. Biochemical processes therefore must play a fundamental role in controlling hydrogen isotope fractionation during secondary compound biosynthesis. Different biosynthetic pathways utilize discrete hydrogen pools, and occur within distinct cell compartments. We analysed hydrogen isotope compositions of C16 and C18 fatty acids and phytol from 7 saltmarsh plants, and compared these data with: (i) leaf water and n‐alkane δ2H; (ii) leaf carbon and nitrogen contents; and (iv) nitrogen isotopes of bulk tissue, to evaluate the relationship between biochemical processes, cellular compartmentalization, and hydrogen isotope fractionation. Interspecies variation in chloroplastic fatty acids and phytol δ2H exceeds leaf water δ2H, indicating that different commitments of metabolites among species at branching points in chloroplast metabolic processes may be important determinants of lipid δ2H values. Dominant osmoregulatory strategies, in particular, show strong correlation with leaf wax n‐alkane δ2H. Species that preferentially produce nitrogenous compounds (dicots/shrubs) as protective solutes have 2H‐enriched n‐alkanes relative to species that produce mainly carbohydrates (monocots). n‐Alkane δ2H values, in combination with δ15N data and elemental (C, N) composition, together provide information about biochemical environmental adaptations exhibited by different higher plant species in response to environmental stresses. Thus, while spatial and temporal integration of biomarkers may produce an isotopic record of ecosystem function, biomarkers from individual plant or microbial remains may hold additional details into biologic function and adaptation to ancient environments.