The Neanderthal Meal: A New Perspective Using Faecal Biomarkers

Neanderthal dietary reconstructions have, to date, been based on indirect evidence and may underestimate the significance of plants as a food source. While zooarchaeological and stable isotope data have conveyed an image of Neanderthals as largely carnivorous, studies on dental calculus and scattered palaeobotanical evidence suggest some degree of contribution of plants to their diet. However, both views remain plausible and there is no categorical indication of an omnivorous diet. Here we present direct evidence of Neanderthal diet using faecal biomarkers, a valuable analytical tool for identifying dietary provenance. Our gas chromatography-mass spectrometry results from El Salt (Spain), a Middle Palaeolithic site dating to ca. 50,000 yr. BP, represents the oldest positive identification of human faecal matter. We show that Neanderthals, like anatomically modern humans, have a high rate of conversion of cholesterol to coprostanol related to the presence of required bacteria in their guts. Analysis of five sediment samples from different occupation floors suggests that Neanderthals predominantly consumed meat, as indicated by high coprostanol proportions, but also had significant plant intake, as shown by the presence of 5β-stigmastanol. This study highlights the applicability of the biomarker approach in Pleistocene contexts as a provider of direct palaeodietary information and supports the opportunity for further research into cholesterol metabolism throughout human evolution.NASA Astrobiology Institute (Grant NNA13AA90A

An approach from organic chemistry to the study of the hearths of the Middle Palaeolithic archaeological site at El Salt (Alcoi, Alicante, Spain)

Presentem un estudi preliminar dels lípids continguts en els sediments de les estructures de combustió conservades al jaciment del Paleolític Mitjà del Salt, per a reconstruir-ne les històries respectives. Aquestes anàlisis afavoreixen la comprensió del funcionament dels focs prehistòrics mitjançant la informació que es deriva de la determinació dels compostos orgànics, així com de la seua associació amb altres elements termoalterats. Paraules clau: Evidències de combustió. Matèria orgànica. Neandertals. Anàlisis lipídiques. BiomarcadorsPresentamos un estudio preliminar de los lípidos contenidos en los sedimentos de las estructuras de combustión conservadas en el yacimiento del Paleolítico medio de El Salt para reconstruir sus historias respectivas. Estos análisis favorecen la comprensión del funcionamiento de los fuegos prehistóricos mediante la información que se deriva de la determinación de los compuestos orgánicos, así como de su asociación con otros elementos termoalterados. Palabras clave: Evidencias de combustión. Materia orgánica. Neandertales. Análisis lipídicos. Biomarcadores.We present a preliminary chemical study of lipids isolated from sedimentary samples from the Middle Palaeolithic fireplaces of El Salt archaeological site. This enables us to contemplate a certain number of elements that are used for the reconstruction of the respective histories of the combustion structures studied. The lipidic analysis allows us to define the function of prehistoric combustion structures through the examination of preserved organic compounds and their association with burnt remains. Key words: Evidences of combustion. Organic matter. Neanderthal. Lipidic analysis. Biomarkers

Elevated rates of horizontal gene transfer in the industrialized human microbiome

Industrialization has impacted the human gut ecosystem, resulting in altered microbiome composition and diversity. Whether bacterial genomes may also adapt to the industrialization of their host populations remains largely unexplored. Here, we investigate the extent to which the rates and targets of horizontal gene transfer (HGT) vary across thousands of bacterial strains from 15 human populations spanning a range of industrialization. We show that HGTs have accumulated in the microbiome over recent host generations and that HGT occurs at high frequency within individuals. Comparison across human populations reveals that industrialized lifestyles are associated with higher HGT rates and that the functions of HGTs are related to the level of host industrialization. Our results suggest that gut bacteria continuously acquire new functionality based on host lifestyle and that high rates of HGT may be a recent development in human history linked to industrialization.Peer reviewe

New Insights into the Evolution of the Human Diet from Faecal Biomarker Analysis in Wild Chimpanzee and Gorilla Faeces

Our understanding of early human diets is based on reconstructed biomechanics of hominin jaws, bone and teeth isotopic data, tooth wear patterns, lithic, taphonomic and zooarchaeological data, which do not provide information about the relative amounts of different types of foods that contributed most to early human diets. Faecal biomarkers are proving to be a valuable tool in identifying relative proportions of plant and animal tissues in Palaeolithic diets. A limiting factor in the application of the faecal biomarker approach is the striking absence of data related to the occurrence of faecal biomarkers in non-human primate faeces. In this study we explored the nature and proportions of sterols and stanols excreted by our closest living relatives. This investigation reports the first faecal biomarker data for wild chimpanzee (Pan troglodytes) and mountain gorilla (Gorilla beringei). Our results suggest that the chemometric analysis of faecal biomarkers is a useful tool for distinguishing between NHP and human faecal matter, and hence, it could provide information for palaeodietary research and early human diets.Anthropolog

New evidence of early Neanderthal disappearance in the Iberian Peninsula

International audienc

New evidence of early Neanderthal disappearance in the Iberian Peninsula

The timing of the end of the Middle Palaeolithic and the disappearance of Neanderthals continue to be strongly debated. Current chronometric evidence from different European sites pushes the end of the Middle Palaeolithic throughout the continent back to around 42 thousand years ago (ka). This has called into question some of the dates from the Iberian Peninsula, previously considered as one of the last refuge zones of the Neanderthals. Evidence of Neanderthal occupation in Iberia after 42 ka is now very scarce and open to debate on chronological and technological grounds. Here we report thermoluminescence (TL) and optically stimulated luminescence (OSL) dates from El Salt, a Middle Palaeolithic site in Alicante, Spain, the archaeological sequence of which shows a transition from recurrent to sporadic human occupation culminating in the abandonment of the site. The new dates place this sequence within MIS 3, between ca. 60 and 45 ka. An abrupt sedimentary change towards the top of the sequence suggests a strong aridification episode coinciding with the last Neanderthal occupation of the site. These results are in agreement with current chronometric data from other sites in the Iberian Peninsula and point towards possible breakdown and disappearance of the Neanderthal local population around the time of the Heinrich 5 event. Iberian sites with recent dates (<40 ka) attributed to the Middle Palaeolithic should be revised in the light of these data.Archaeological research at El Salt is funded by the Spanish Government project ‘La Desaparición de los grupos neandertales en la region central del Mediterráneo Ibérico. Una propuesta metodológica de aproximación al proceso histórico y al marco paleoambiental’ (HAR2012-32703, MICINN-FEDER), and Direcció General de Cultura (Consellería de Educació, Cultura i Esports. Generalitat Valenciana).Peer Reviewe

Discriminant analysis.

<p>The canonical discriminant analysis plot shows NHP and Neanderthal samples. Group 1 corresponds to the chimpanzee samples, the second to gorillas and the third to Neanderthals.</p

Partial chromatogram showing evidence for plant intake.

<p>Partial chromatogram of summed GC-MS transition for C₂₇+C₂₈+C₂₉ sterols and stanols from the oldest sample (WL H44). Retention peaks matched those of reference samples of fresh faecal matter from primates and herbivores.</p

Chimpanzee stanol partial chromatogram.

<p>Comparison of the m/z 215 ion chromatograms for the neutral lipid fraction from sample 3 (CH5) and 10 (CH3) collected from the same chimpanzee in different moments.</p