DEER PALAEOBIOLOGY · Palaeobiological inference through phylogenetic analysis of Pleistocene deer

Palaeobiological inference through phylogenetic analysis of Pleistocene deer

Project context Deer are abundant in the European Quaternary and their high rate of species turnover and evolutionary change make them a good example of adaptive radiation. Three, probably inter-related, deer taxa have been the focus of this project: the Pliocene to Early Pleistocene Eucladoceros species ('comb antlered deer'), the Middle- Late Pleistocene Megacerini ('giant deer'), and the Pliocene to Early Pleistocene Dama-like deer (fallow deer). Project results The first stage of the research focused on taxonomic revision. Scrutiny of the original descriptions has been carried out to assess the validity, content and description of each species. This has been accompanied by a re-study of the type specimens and of the most informative specimens in Europe. To better characterise each species, dental and postcranial remains have been analysed in detail, seeking morphological features peculiar to the different species. The definition of these features enables the identification of isolated remains and provides many more characters for phylogenetic analysis. All the specimens have been catalogued in an extensive database, recording locality, stratigraphy, and comprehensive metric, morphologic, and photographic data. In the metric database, numerous measurements have been taken on each specimen, including new measurements devised to capture significant variation. This metric database will be used to assess variation in size or shape among different sites. In the morphological database, the characters of Lister et al. (2005) have been scored and new characters and character states added. These new characters required detailed study of key European collections where teeth and bones are associated with antlers. Since deer show strong intra-specific variability, as many individuals as possible have been scored in each sample. The transformed matrix of morphological characters will be analysed under maximum-parsimony methods, using PAUP*4.0. Project outcomes From a taxonomic point of view, the first clear output is the discovery of a new species of fallow deer from the early Middle Pleistocene of Pakefield (England) and Soleilhac (France). This species bridges the gap in age and morphology between the Pliocene-Early Pleistocene forms referred to "Pseudodama" and the late Middle Pleistocene-Recent Dama. The presence of both primitive and advanced characters suggests it could be an early member of the stem group of recent fallow deer. This will be tested by a cladistic study incorporating all skeletal elements. The description of this new species in a peer-reviewed journal is a priority in the coming months. Because the fellow gained a full-time university position, the award was terminated after 15 months of full-time equivalent work (of the 23 months planned). As a result, both the morphometric and phylogenetic analyses remain to be run. In turn, the morphometric and phylogenetic analyses will be the starting point for exploring the mode, timing and pattern of evolution and addressing some important palaeo-biological questions. Resolving the relationships among the different deer taxa, and linking the nodes of the cladogram to known climatic events, will enable an examination of environmental correlates of accelerated evolution and speciation, and of evolutionary stasis. Mapping variation in body size and adaptive features of the individual taxa, together with chronological and palaeo-environmental data, on to the phylogenetic tree should provide insight into several questions. Examples include the association between size and climate, or size and isolation, the relationship of antler form to phylogeny versus habitat, and the adaptive meaning of some morphological features with respect to the environment. It is our intention to continue the collaboration and complete all of these tasks in the coming 18 months.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз