In the context of an ongoing mass extinction event, wild animals are now facing the double challenge imposed by direct human alteration of their habitat as well as the indirect consequences of climate change. While research on modern populations provides data on the impact of human land use and how to compensate for it, the response of large mammals to climate change is harder to grasp and subsequently predict without a deep-time perspective. Nevertheless, the palaeontological and archaeological records provide a unique window of opportunity for researchers seeking to investigate the response of wild animals and human populations to environmental change in the long-term. The Palaeolithic is an invaluable source of insight into human – animal – environment interactions, as it provides a deep time perspective of human resilience in the face of changing resources, environmental risk, and catastrophe. In this vein, the DeerPal project hopes to acquire new fundamental knowledge on the palaeoecology of animal communities faced with major and rapid climate changes, as well as increase our understanding of how human societies coped with these changes in the past. It focuses on the history of two large mammal species, reindeer (Rangifer tarandus) and red deer (Cervus elaphus), during the Late Pleistocene epoch, prior to the advent of agriculture, when these animals were key resources to hunter-gatherer groups. At a crossroads between archaeology and palaeoecology, the DeerPal project goals are twofold: 1) To document past variability in reindeer and red deer ecological niches and behaviours and test whether variability is higher than what can be inferred from current highly anthropised ecosystems, thus providing a more complete vision of cervid ecology through an evolutionary study of their past adaptations to natural habitats. 2) To carry out a deep-time retrospective study on the impact of climatic changes on two wild mammal species that were central resources to hunter-gatherer societies, and thus provide a necessary backdrop for understanding the scale of climate changes and resource variability that human groups had to adapt to, before altering wild animal habitats. To achieve its objectives, the DeerPal project will test, for the first time, the large-scale and simultaneous application of four state-of-the-art analytical techniques (dental microwear texture analysis, stable isotopic studies, cementochronology and 3D morphometric methods) for archaeological assemblage analysis in order to better describe the past ecology and ethology of prey communities. This integrated perspective will allow us to more fully explore human – animal – environment interactions during the Palaeolithic. Two archaeological periods with significant environmental and cultural shifts were selected for study, corresponding to two distinct research angles: the long sequences of the Middle Palaeolithic of southwestern France, for a diachronic approach, and Late Glacial sites from the Pyrenees to the Paris Basin, for a large biogeographical perspective on the response of past cervid communities to climate warming. Run by three French partner institutions with complementary equipment and expertise (TRACES - University of Toulouse Jean Jaurès, PACEA - University of Bordeaux, and Biogéosciences - University of Bourgogne Franche-Comté), the DeerPal project forms an interdisciplinary consortium that includes palaeoecologists, archaeologists and geochemists from 6 countries and 11 institutions. Specific public outreach activities will provide novel perspectives on the impact of environmental change on humans in the past to the public, dispensing a much-need historical perspective relative to what lies in our collective future.

Since the Cambrian, biominerals contribute to the adaptation of living organisms to different environments by fulfilling various functions including support, locomotion, aggression, protection, camouflage, magnetic navigation, mastication, gravity sensor, and vision. These functions are necessarily associated with adapted morphologies. One of the aims of this project is to contribute understanding how organisms make these complex morphologies. A major difference between biogenic and inorganic calcites is that the former contain almost invariably a small proportion of organic matter. The working hypothesis of our project is that organic molecules play a major role in biomineral structuring at the nanoscale, and that biominerals are true organic/inorganic nanohybrids. However, even if many studies have been dedicated to determining the complex nature of OM, little is known about the structural relationships between OM and crystal: is OM present as inclusions without interaction with the crystal or is it structurally linked to calcite? The aim of this project is to explore the physical relationships between organic molecules and crystal surfaces (and volumes) in biominerals. For this purpose we plan to characterize and understand the nature of OM/crystal interactions in calcitic biominerals using a combination of direct and inverse methods. The direct approach encompasses (1) the synthesis of calcite in solution, in the presence of model organic molecules, and (2) the study of the behavior of model organic molecules (polyenes) on cleaved calcite faces. The inverse method includes the study of some model biominerals (precious corals of the Corallium genus, and selected mollusks with one or more calcitic shell layers such as Pinna or Crassostrea genera. For this project, we will use (sometimes develop) complementary sophisticated techniques involving a range of spectroscopic methods, ultra-high vacuum scanning probe microscopy, atomic force microscopy with antibody-functionalized tips, and synchrotron micro- and nano-tomographies. The consortium involves three geographical and administrative entities and four research groups: SOLEIL (Gif/Yvette), CINaM (Marseille), Biogeoscience and ICB (both at Dijon), at the interface between mineralogy, biology, and physics, combining technical expertise and knowledge on both organic and inorganic parts of biominerals. The organic/inorganic interface is a promising field of research in almost all scientific disciplines. In Earth and Materials Sciences the study of biominerals has implications on the origin and evolution of life, ecology of marine environments, paleoenvironments, paleoclimatology, and elaboration of new efficient and sustainable materials with tailored mechanical properties by soft chemistry.

Vertebrate females exposed to pathogens transfer specific antibodies to their offspring, providing them with a temporary protection during the time required for their immune system to mature. Invertebrates lack the antibodies that vertebrate females transfer to their offspring. However, maternal transfer of immunity, also referred to as “trans-generational immune priming” (TGIP), occurs in invertebrates too, suggesting that it has to be achieved by other, yet unknown, mechanisms. Evidences of TGIP in invertebrates are largely phenomenological and await the elucidation of the underlying mechanisms as well as its evolutionary and ecological implications. So far, TGIP in invertebrates has been probably best described in the mealworm beetle, Tenebrio molitor (Coleopteran, Tenebrionidae) in terms of both immunological and fitness consequences for the offspring through various developmental stages. T. molitor females subjected to a bacterially based benign immune challenge produce eggs and larvae that contain high antibacterial activity and adult offspring with an increased concentration of circulating immune cells. Such an investment into offspring immunity is variable among females. It constrains the female immune responsiveness and fecundity and slows down the growth rate of the offspring. Yet the physiological and molecular mechanisms through which TGIP is achieved are not known. Furthermore, it is not known whether variation among females in investment into TGIP has a genetic basis. If so, variation may be maintained by genetic constrains with other life history traits and selective pressures imposed by parasite persistence from one generation to the next. In this project, we aim to study TGIP in T. molitor through the investigation of its underlying mechanism(s) and effects at the physiological and molecular levels. We will use several complementary methodologies, including proteomics and transcriptomics to identify the main immune effectors and immune genes associated to TGIP, microscopy to determine the site of their production and functional approaches to experimentally validate their importance in this phenomenon. We will also investigate the source of variation in TGIP among females through the estimation of its genetic variance and covariance with life-history traits of the mother and her offspring in order to understand the conditions of its evolution and its maintenance in natural populations. The outcome of such a study will provide unprecedented advances on the functional aspects of TGIP as well as on its ecology and evolution in invertebrate systems.