Recherche de candidat à présenter au concours de l’Ecole Doctorale 227 Science de la Nature et de l’Homme : Ecologie et Evolution du Muséum National d’Histoire Naturelle (MNHN).
Encadrants : Thomas Haevermans & Ben Warren,
UMR 7205 Institut de Systématique, Evolution, Biodiversité
Title: Using insular macroevolutionary data to investigate the role of ecological opportunity in driving evolutionary radiations
Objective: To use phylogenetic and ecological trait data from island plants lineages to investigate the roles of dispersal ability and ecological opportunity in driving evolutionary radiations.
Summary of the project:
Evolutionary diversification is the fundamental process by which all species have been generated. At any defined spatial scale, we find that some lineages have diversified more than others. Although there exist a wide variety of case-specific explanations for differences in diversification rate between geographic regions, and among lineages within any one geographic area, our ability to identify general tenets of broad taxonomic and geographic scope have so far been limited. Among the obstacles normally encountered in making such inferences is uncertainty in the spatial scale in which speciation has occurred.
Organisms endemic to oceanic islands provide significant advantages in inferring the spatial scale of speciation, since their longstanding boundaries allow in situ speciation (within the island) to be readily distinguished from speciation that is the result of immigration from outside sources. The opportunity afforded by such island lineages has already been exploited in a landmark paper (Kisel & Barraclough 2010) using multiple taxa that vary in their dispersal ability to show that speciation has a spatial scale that depends on the level of gene flow. The insights provided by this paper regarding speciation (division of one species into two) lead to further questions regarding the process by which any one lineage accumulates multiple species (evolutionary radiation sensu lato) within any defined geographic area (Hughes et al. 2015). In particular:
– Do poor dispersers have an intrinsically higher potential to radiate within any defined geographic region than good dispersers?
– Are there systematic differences in the ecological opportunity for radiation experienced by lineages that differ in dispersal capacity?
Compared with other institutions worldwide, the MNHN has specialists in an unusually wide variety of insular taxa, and collections providing an abundant source of trait data. This project is focussed on an island archipelago and taxon familiar to both supervisors – plants of the Mascarene archipelago, Indian Ocean, that vary in dispersal capacity, including animal-dispersed and wind-dispersed taxa (trees, herbs, shrubs, sedges and ferns). Considering groups for which there exist published molecular phylogenetic data, the student will quantify trait data for each radiation considered, benefitting from extensive collections in the MNHN herbarium. Colonisation history and trait evolution will be quantified and dated objectively (with confidence intervals), using biogeographic and ancestral state reconstruction methods, as well as relaxed clock dating with external calibrations. Synthesised results across multiple taxa will be used to compare rates of:
– Trait evolution;
– Island colonisation;
– Accumulation of sympatric species per radiation, both through inter-island colonisation and within-island speciation.
Hughes, C.E., Nyffler, R. & Linder, H.P. (2015). Evolutionary plant radiations: where, when, why and how? New Phytologist, 207, 249-253
Kisel, Y. & Barraclough, T.G. (2010). Speciation Has a Spatial Scale That Depends on Levels of Gene Flow. American Naturalist, 175, 316-334
We are looking for a student with a Masters degree who has followed modules in evolutionary biology, and with a taste for ecology.
Candidates should have proven proficiency in submitting written reports, and ideally demonstrate experience in one or more of the following areas:
– molecular phylogenetics (phylogenetic reconstruction & dating, biogeographic & ancestral state reconstruction)
– morphometrics (comparative analyses of trait data)
– testing correlations between different eco-evolutionary variables
First-hand knowledge or interest in one or more of the groups studied would be a bonus. While the project is centred on plants, there is much potential to also include animal taxa, and we encourage applications from students with interests in the ecology and evolution of a wide variety of taxa.
Written applications should be submitted using the following link:
Applications can be written in French or English and should include:
– Letter of motivation
– Copy of Masters diploma
– Relevé des notes M1 and 1st semester of M2 (or all of M2, for candidates having completed their M2).
Following the procedure of the ED 227 (detailed in the link above), short-listed candidates will first be interviewed by the supervisors at the MNHN. A single selected candidate will then be asked to submit an administrative dossier, and will be auditioned by the ED 227 in Paris between July 1-3, 2019.
While we welcome applications from graduates of any university worldwide, we regret that the system does not cover travel expenses.