Marie-Anne Julien

Middle Pleistocene ecology and Neanderthal subsistence: Insights from stable isotope analyses in Payre (Ardèche, southeastern France)

The Middle Palaeolithic site of Payre in southeastern France yields abundant archaeological material associated with fossil hominid remains. With its long sequence of Middle Pleistocene deposits, Payre is a key site to study the Middle Palaeolithic chronology of this region. This study is the first to investigate carbon and oxygen isotope contents of Neanderthal tooth enamel bioapatite, together with a wide range of herbivorous and carnivorous species. The aim is to contribute to the understanding of hunting behaviour, resource partitioning, diet and habitat use of animals and Neanderthals through a palaeoecological reconstruction. Local topography had a visible influence on carbon and oxygen stable isotope values recorded in herbivore tooth enamel. This was used to investigate possible habitats of herbivores. The different herbivorous species do not show large variations of their carbon and oxygen isotope values through time, indicating niche conservatism from OIS 8-7 to OIS 6-5, i.e., independently of palaeoclimatic and palaeoenvironmental variations. Based on these new observations, we conclude that Neanderthals employed a stable subsistence strategy over time, using a variety of local resources, with resource partitioning visible between humans and carnivores, especially wolves. A comparison of the results of stable isotopic investigation with the results of tooth wear analyses previously conducted on the same teeth allowed us to demonstrate that grazing and browsing do not bind animals to a specific habitat in a C3 environment as reflected in the isotopic values.

Early cave art and ancient DNA record the origin of European bison

The two living species of bison (European and American) are among the few terrestrial megafauna to have survived the late Pleistocene extinctions. Despite the extensive bovid fossil record in Eurasia, the evolutionary history of the European bison (or wisent, Bison bonasus) before the Holocene (<11.7 thousand years ago (kya)) remains a mystery. We use complete ancient mitochondrial genomes and genome-wide nuclear DNA surveys to reveal that the wisent is the product of hybridization between the extinct steppe bison (Bison priscus) and ancestors of modern cattle (aurochs, Bos primigenius) before 120u2009kya, and contains up to 10% aurochs genomic ancestry. Although undetected within the fossil record, ancestors of the wisent have alternated ecological dominance with steppe bison in association with major environmental shifts since at least 55u2009kya. Early cave artists recorded distinct morphological forms consistent with these replacement events, around the Last Glacial Maximum (LGM, ∼21–18u2009kya).

Effect of X-ray irradiation on ancient DNA in sub-fossil bones : guidelines for safe X-ray imaging

Sub-fossilised remains may still contain highly degraded ancient DNA (aDNA) useful for palaeogenetic investigations. Whether X-ray computed [micro-] tomography ([μ]CT) imaging of these fossils may further damage aDNA remains debated. Although the effect of X-ray on DNA in living organisms is well documented, its impact on aDNA molecules is unexplored. Here we investigate the effects of synchrotron X-ray irradiation on aDNA from Pleistocene bones. A clear correlation appears between decreasing aDNA quantities and accumulating X-ray dose-levels above 2000u2009Gray (Gy). We further find that strong X-ray irradiation reduces the amount of nucleotide misincorporations at the aDNA molecule ends. No representative effect can be detected for doses below 200u2009Gy. Dosimetry shows that conventional μCT usually does not reach the risky dose level, while classical synchrotron imaging can degrade aDNA significantly. Optimised synchrotron protocols and simple rules introduced here are sufficient to ensure that fossils can be scanned without impairing future aDNA studies.

The archaeology of persistent places: The Palaeolithic case of la Cotte de St Brelade, Jersey

Abstract Excavations at the Middle Pleistocene site of La Cotte de St Brelade, on the island of Jersey in the English Channel, have revealed a long sequence of occupation. The continued use of the site by Neanderthals throughout an extended period of changing climate and environment reveals how, despite changes in the types of behaviour recorded at the site, La Cotte emerged as a persistent place in the memory and landscape of its early hominin inhabitants. The sites status as a persistent place for these people suggests a level of social and cognitive development permitting reference to and knowledge of places distant in time and space as long ago as at least MIS 7.