sábado, mayo 26, 2012

Oferta de tesis sobre dientes de mamíferos en París.

Se ha ofertado una beca para hacer la tesis doctoral con dientes de mamíferos en París (Ecle Pratique des Hautes Etudes). Os adjuntamos la información y contactos. 

Title: Evolutionary novelties and emergence of dental phenotypes in Mammals.

Host laboratory: EPHE Paléobiodiversité et évolution – UMR 6282 Biogéosciences

Background: Mammals display a high dental diversity in terms of number and complexity of teeth. This diversity attests of the influence of several parameters including diet and suggests a mammalian morphospace on which shape changes are possible in every direction. However, morphological changes within lineages seem to be constrained. Developmental processes producing the phenotypic expression of genetic variation are under natural selection. Favouring or limiting some directions of change in the morphospace, these processes will modify the evolutionary capacity on the short and long time scales. These constraints can influence the diversity of a clade (at a macroevolutionay level), forcing the accumulation of new species in one peculiar direction of the morphospace. In the dental raw theveruption of teeth follows an iterative developmental model in which interactions between teeth are controlled and lead to a final dental phenotype. Within teeth themselves, interactions occur between cusps following the same iterations and defining tooth morphology (number, position and shape of cusps). Some recent works showed that small modifications of cusp interactions can imply large modifications at the tooth scale, and for instance the development of new cusps.

Objectives – This subject will focus on two different mammal groups (rodents and primates) at different scales (population, lineages, clades). Complementary approaches will be addressed by both groups. Rodents display a reduced variation of the dental formula but a high diversity of molar form. In primates, the major part of variation occurs on the number of teeth and number of cusps on each tooth rather than on their shape. The main goal of this project is to understand the cusp interactions and their consequences on dental formula and teeth complexity (gains or losses of cusps and teeth). These variations of complexity will be analysed in the historic and evolutionary frameworks of the groups, and of the biotic (size, diet) and abiotic parameters.

The subject (and ONE applicant) will be proposed to the EPHE, examined and the applicant will be interviewed in order to get the fellowship. Interviews are planned on July  4th and 5th in Paris. For further informations, please go to the EPHE website: http://www.ephe.sorbonne.fr/recherche/contrat-doctoral-2012.html). Applicants must contact Pr.Sophie Montuire. (sophie.montuire@u-bourgogne.fr) before june 20th  2012