Taphonomy of DNA in rodents.

International audienceMicromammals, particularly rodents, are important paleoenvironmental indicators and their investigation has the potential to deliver a large amount of invaluable information for the interpretation of archeological sites and past environments. Data from paleogenetic and paleogenomic analyses of this important resource could contribute substantially to these interpretations. Most rodent remains, however, originate from accumulations through predators, such as pellets of raptors. In modern pellets, we could show that the passage of rodents through the digestive tract heavily damages DNA in their bones and teeth although the extent of DNA damage depends on the location of the remains in the stomach of the predator and the duration they are subject to the attack of the gastric juices. Thus, a minute portion of DNA can be rather well preserved. It is likely that it is this portion that is prone to long-term preservation since we could show DNA to be preserved in rodent remains from the El Harhoura2 cave in Morocco in levels dated to ca. 6,000 and 44,000 years. We also performed experiments of monitored taphonomy and analyzed DNA degradation and the transformation of the microbiome in bones of mice buried for different time intervals covering a period of 2 years. These experiments shed light on the processes through which biological specimens turn into environmental specimens

Taphonomy of DNA in rodents.

International audienceMicromammals, particularly rodents, are important paleoenvironmental indicators and their investigation has the potential to deliver a large amount of invaluable information for the interpretation of archeological sites and past environments. Data from paleogenetic and paleogenomic analyses of this important resource could contribute substantially to these interpretations. Most rodent remains, however, originate from accumulations through predators, such as pellets of raptors. In modern pellets, we could show that the passage of rodents through the digestive tract heavily damages DNA in their bones and teeth although the extent of DNA damage depends on the location of the remains in the stomach of the predator and the duration they are subject to the attack of the gastric juices. Thus, a minute portion of DNA can be rather well preserved. It is likely that it is this portion that is prone to long-term preservation since we could show DNA to be preserved in rodent remains from the El Harhoura2 cave in Morocco in levels dated to ca. 6,000 and 44,000 years. We also performed experiments of monitored taphonomy and analyzed DNA degradation and the transformation of the microbiome in bones of mice buried for different time intervals covering a period of 2 years. These experiments shed light on the processes through which biological specimens turn into environmental specimens

Systèmes policiers

Le thème du carnet est celui de l'étude de la construction et des recompositions des systèmes policiers européens aux 18e et 19e siècles, en Europe et dans les prolongements territoriaux que constituent les Empires coloniaux européens, dans une approche interdisciplinaire. Par systèmes policiers, on entend des configurations policières particulières qui se nouent et se cristallisent autour de lieux, de situations et d’objets spécifiques. La période des 18e-19e siècles correspond à un moment c..

Gibraltar Neanderthals and results of recent excavations in Gorham's, Vanguard and Ibex Caves

While the sites of Forbes' Quarry and Devil's Tower are, respectively, unpromising and probably too dangerous for further excavation, there are several other sites on the Rock preserving evidence of Neanderthal activities. One, Ibex Cave, lies high up on the eastern face of the Rock, while four others lie to the southeast, close to the sea near 'Governor's Beach'. The present beach mainly consists of fine limestone blast debris from military tunnelling operations, but there are also cemented remnants of more ancient beaches which presumably accumulated during Oxygen Isotope Stage 5. The caves are named (from the south) Bennett's, Gorham's, Vanguard and Boat Hoist. Three of these caves (Ibex, Gorham's and Vanguard) have been excavated since 1994 as part of the Gibraltar Caves Project; some of the initial results of this work are presented below. Further details will appear in the proceedings of the Gibraltar conference held in August to celebrate the 150th anniversary of the finding of the Forbes' Quarry skull (Stringer et al. in preparation). The excavations at Gorham's and Vanguard Caves are already beginning to yield significant results relating to the palaeontological, archaeological and palaeoenvironmental aspects of the Neanderthals and their modern human successors. The integration of new AMS and other dating results with sediments analysis should help us compare the sequences in both caves and to provide frameworks for situating human behaviour. For example, it would be interesting to know whether changes in sea level and resulting reconfiguration of the coastal plain were major factors responsbile in the Neanderthal exploitation of highly local raw materials for tool-making and the frequency of gathering of marine/estuarine foods. Using this information and comparing the archaeological evidence from the Middle and Upper Palaeolithic levels at the sites will help to place the Gibraltar finds in their European and Mediterranean contexts

Owl pellets: a wise DNA source for small mammal genetics

International audienc

Palaeoecological reconstructions of the Middle to Late Pleistocene occupations in the Southern Caucasus using rodent assemblages

Located at the crossroads between Africa, Europe and Asia, the Southern Caucasus is a prime location to study occupations by H. heidelbergensis, H. neanderthalensis and anatomically modern humans. Azokh Cave is an important site for the understanding of human evolution in its archaeological, palaeontological, environmental and ecological context. The main objective of this work is to use rodents to infer the climatic and environmental conditions that prevailed during the formation of the site. The small-mammal remains come from the archaeological excavation campaigns carried out in Azokh 1 in 2003, 2005, 2014, 2015 and 2018; they are from Unit V, Units III–IV and Unit II. The small-mammal assemblage is composed of at least 13 taxa: seven arvicoline, two cricetine, two gerbilline, one dipodid and one murine species. Units III–IV do not yield enough material to draw palaeoclimatic inferences. The palaeoclimatic conditions for Units V and II, ascertained by means of the bioclimatic model, suggest temperatures and precipitation similar to nowadays; the climate seems to be relatively warm-temperate in both units. The palaeoenvironmental reconstruction by means of habitat weighting points to an environment mainly composed of desert and steppe habitats, as well as portions of grassland and forest. This interpretation differs from that inferred from the large-mammal and archaeobotanical data, which indicate a woodland environment. These differences could be explained by the origin of the accumulation. There was no evidence of a major palaeoenvironmental or palaeoclimatic change between the Middle and Late Pleistocene layers, indicating favourable conditions throughout the study period