Impact of modern cattle feeding practices onmilk fatty acid stable carbon isotope compositions emphasise the need for caution in selecting reference animal tissues and products for archaeological investigations

Degraded animal fats, characterised by the presence of palmitic (C16:0) and stearic (C18:0) fatty acids and related glycerolipids are the most common class of preserved lipids in organic residues trapped in the porous clay matrix of archaeological ceramic vessels. The ubiquitous presence of fatty acids in animal fats and plant oils precludes identification of fat types by the solely molecular composition of residues. Hence, animal fats are identified by determining their fatty acyl lipid distributions and stable carbon (δ13C) values allowing distinctions to be drawn between non-ruminant and ruminant, and dairy and adipose fats. The Δ13C proxy (= δ13C18:0 - δ13C16:0) originally proposed in the 1990s by Evershed and co-workers was based on modern reference fats sampled from animals raised in Britain on C3 plant diets. Further analyses on adipose and dairy fats from ruminants grazing in a wide range of isoscapes have shown that the Δ13C proxy can be applied in mixed C3/C4 environments, such as in Africa. Here we show, however, through the investigation of milk fats, how the Δ13C proxy can be perturbed when animals are reared on modern diets, specifically maize silage. It is thus shown that extreme care has to be taken when choosing modern reference fats for archaeological studies, and especially that insecurely sourced animal fats should be excluded from such databases

Impact of modern cattle feeding practices on milk fatty acid stable carbon isotope compositions emphasise the need for caution in selecting reference animal tissues and products for archaeological investigations

Degraded animal fats, characterised by the presence of palmitic (C16:0) and stearic (C18:0) fatty acids and related glycerolipids are the most common class of preserved lipids in organic residues trapped in the porous clay matrix of archaeological ceramic vessels. The ubiquitous presence of fatty acids in animal fats and plant oils precludes identification of fat types by the solely molecular composition of residues. Hence, animal fats are identified by determining their fatty acyl lipid distributions and stable carbon (δ13C) values allowing distinctions to be drawn between non-ruminant and ruminant, and dairy and adipose fats. The Δ13C proxy (= δ13C18:0 - δ13C16:0) originally proposed in the 1990s by Evershed and co-workers was based on modern reference fats sampled from animals raised in Britain on C3 plant diets. Further analyses on adipose and dairy fats from ruminants grazing in a wide range of isoscapes have shown that the Δ13C proxy can be applied in mixed C3/C4 environments, such as in Africa. Here we show, however, through the investigation of milk fats, how the Δ13C proxy can be perturbed when animals are reared on modern diets, specifically maize silage. It is thus shown that extreme care has to be taken when choosing modern reference fats for archaeological studies, and especially that insecurely sourced animal fats should be excluded from such databases

Regional asynchronicity in dairy production and processing in early farming communities of the northern Mediterranean

In the absence of any direct evidence, the relative importance of meat and dairy productions to Neolithic prehistoric Mediterranean communities has been extensively debated. Here, we combine lipid residue analysis of ceramic vessels with osteo-archaeological age-at-death analysis from 82 northern Mediterranean and Near Eastern sites dating from the seventh to fifth millennia BC to address this question. The findings show variable intensities in dairy and nondairy activities in the Mediterranean region with the slaughter profiles of domesticated ruminants mirroring the results of the organic residue analyses. The finding of milk residues in very early Neolithic pottery (seventh millennium BC) from both the east and west of the region contrasts with much lower intensities in sites of northern Greece, where pig bones are present in higher frequencies compared with other locations. In this region, the slaughter profiles of all domesticated ruminants suggest meat production predominated. Overall, it appears that milk or the by-products of milk was an important foodstuff, which may have contributed significantly to the spread of these cultural groups by providing a nourishing and sustainable product for early farming communities

Interpreting ancient food practices:Stable isotope and molecular analyses of visible and absorbed residues from a year-long cooking experiment

Chemical analyses of carbonized and absorbed organic residues from archaeological ceramic cooking vessels can provide a unique window into the culinary cultures of ancient people, resource use, and environmental effects by identifying ingredients used in ancient meals. However, it remains uncertain whether recovered organic residues represent only the final foodstuffs prepared or are the accumulation of various cooking events within the same vessel. To assess this, we cooked seven mixtures of C3 and C4 foodstuffs in unglazed pots once per week for one year, then changed recipes between pots for the final cooking events. We conducted bulk stable-isotope analysis and lipid residue analysis on the charred food macro-remains, carbonized thin layer organic patina residues and absorbed lipids over the course of the experiment. Our results indicate that: (1) the composition of charred macro-remains represent the final foodstuffs cooked within vessels, (2) thin-layer patina residues represent a mixture of previous cooking events with bias towards the final product(s) cooked in the pot, and (3) absorbed lipid residues are developed over a number of cooking events and are replaced slowly over time, with little evidence of the final recipe ingredients

Organic residue analysis shows sub-regional patterns in the use of pottery by Northern European hunter–gatherers

The introduction of pottery vessels to Europe has long been seen as closely linked with the spread of agriculture and pastoralism from the Near East. The adoption of pottery technology by hunter–gatherers in Northern and Eastern Europe does not fit this paradigm, and its role within these communities is so far unresolved. To investigate the motivations for hunter–gatherer pottery use, here, we present the systematic analysis of the contents of 528 early vessels from the Baltic Sea region, mostly dating to the late 6th–5th millennium cal BC, using molecular and isotopic characterization techniques. The results demonstrate clear sub-regional trends in the use of ceramics by hunter–gatherers; aquatic resources in the Eastern Baltic, non-ruminant animal fats in the Southeastern Baltic, and a more variable use, including ruminant animal products, in the Western Baltic, potentially including dairy. We found surprisingly little evidence for the use of ceramics for non-culinary activities, such as the production of resins. We attribute the emergence of these subregional cuisines to the diffusion of new culinary ideas afforded by the adoption of pottery, e.g. cooking and combining foods, but culturally contextualized and influenced by traditional practices

Timing and pace of dairying inception and animal husbandry practices across Holocene North Africa

The timing and extent of the adoption and exploitation of domesticates and their secondary products, across Holocene North Africa, has long been the subject of debate. The three distinct areas within the region, Mediterranean north Africa, the Nile Valley and the Sahara, each with extremely diverse environments and ecologies, demonstrate differing trajectories to pastoralism. Here, we address this question using a combination of faunal evidence and organic residue analyses of c. 300 archaeological vessels from sites in Algeria, Libya and Sudan. This synthesis of new and published data provides a broad regional and chronological perspective on the scale and intensity of domestic animal exploitation and the inception of dairying practices in Holocene North Africa. Following the introduction of domesticated animals into the region our results confirm a hiatus of around one thousand years before the adoption of a full pastoral economy, which appears first in the Libyan Sahara, at c. 5200 BCE, subsequently appearing at c. 4600 BCE in the Nile Valley and at 4400–3900 BCE in Mediterranean north Africa

Dairying, diseases and the evolution of lactase persistence in Europe

Update notice Author Correction: Dairying, diseases and the evolution of lactase persistence in Europe (Nature, (2022), 608, 7922, (336-345), 10.1038/s41586-022-05010-7) Nature, Volume 609, Issue 7927, Pages E9, 15 September 2022In European and many African, Middle Eastern and southern Asian populations, lactase persistence (LP) is the most strongly selected monogenic trait to have evolved over the past 10,000 years(1). Although the selection of LP and the consumption of prehistoric milk must be linked, considerable uncertainty remains concerning their spatiotemporal configuration and specific interactions(2,3). Here we provide detailed distributions of milk exploitation across Europe over the past 9,000 years using around 7,000 pottery fat residues from more than 550 archaeological sites. European milk use was widespread from the Neolithic period onwards but varied spatially and temporally in intensity. Notably, LP selection varying with levels of prehistoric milk exploitation is no better at explaining LP allele frequency trajectoriesthan uniform selection since the Neolithic period. In the UK Biobank(4,5) cohort of 500,000 contemporary Europeans, LP genotype was only weakly associated with milk consumption and did not show consistent associations with improved fitness or health indicators. This suggests that other reasons for the beneficial effects of LP should be considered for its rapid frequency increase. We propose that lactase non-persistent individuals consumed milk when it became available but, under conditions of famine and/or increased pathogen exposure, this was disadvantageous, driving LP selection in prehistoric Europe. Comparison of model likelihoods indicates that population fluctuations, settlement density and wild animal exploitation-proxies for these drivers-provide better explanations of LP selection than the extent of milk exploitation. These findings offer new perspectives on prehistoric milk exploitation and LP evolution.Peer reviewe