We invite applications for a PhD position funded by the European Research Council (ERC) for 36 months at the University of Montpellier (France).
Co-supervisors. Dr. Frédéric Delsuc (frederic.delsuc@umontpellier.fr) and Dr. Benoit Nabholz (benoit.nabholz@umontpellier.fr).
Research Unit. Institut des Sciences de l’Evolution de Montpellier, UMR 5554, CNRS, IRD, EPHE, Université de Montpellier, Montpellier, France.
Host Laboratory. Genome Department, Team "Phylogeny and Molecular Evolution" (http://www.isem.univ-montp2.fr/recherche/equipes/phylogenie-et-evolution-moleculaire/personnel/).
Background. Despite its widespread occurrence across the tree of life, many questions still remain unanswered concerning the fascinating phenomenon of convergent evolution. Our objectives with this project are to provide new insights on a textbook example of adaptive evolutionary convergence represented by mammalian myrmecophagous species, in which similar phenotypes evolved independently in several lineages. The acquisition of a myrmecophagous diet almost exclusively composed of ants and/or termites has indeed evolved independently in five placental lineages with armadillos (Cingulata), anteaters (Pilosa), aardvarks (Tubulidentata), pangolins (Pholidota) and aardwolves (Carnivora). However, large-scale comparative genomic studies of myrmecophagous placentals are still lacking. In this ConvergeAnt PhD project, we propose taking advantage of the unique set of convergently evolved characters associated with the ant-eating diet to investigate the molecular mechanisms underlying phenotypical adaptation by analyzing the genomes of myrmecophagous placentals.
Tasks. The main objectives of this PhD project are to reveal the genomic adaptations underlying the convergent evolution of myrmecophagous phenotypes in armadillos, anteaters, aardvarks, pangolins, and aardwolves. The fundamental evolutionary questions we aim to answer by the completion of this project are: (1) Which genomic adaptations have evolved in response to the selective constraints imposed by the myrmecophagous life-style? (2) Do the same genomic adaptations underlie the convergent phenotypes seen in independent ant-eating mammalian lineages? (3) How widespread is adaptive convergent molecular evolution in ant-eating placental genomes? To this aim we will analyse genomic data that are currently produced within the project in the form of both RNAseq experiments and whole genome sequences. We will first focus on candidate genes likely to be involved in the convergent adaptation to the myrmecophagous diet. For these genes, we will perform detailed analyses of molecular evolution based on site- and branch-wise estimations of the non-synonymous to synonymous substitution ratio (dN/dS) in order to investigate the potential occurrence of convergent selective pressures in myrmecophagous lineages. We will then evaluate the extent of genome-wide adaptive convergent molecular evolution in myrmecophages by performing genome-wide survey of convergent and divergent amino acid substitutions using site-heterogeneous mixture models. The aim is to identify genes presenting an excess of adaptive convergent substitutions in myrmecophagous lineages by contrast with non myrmecophagous lineages. Finally, we will investigate the potential parallel evolution of specific gene families such as olfactory and taste receptors. Gene repertoires will be statistically compared among myrmecophagous species to identify potential convergent expansions and/or losses relative to other mammalian species with different diets. Overall, the project will build upon recent experimental and theoretical advances on detecting convergent evolution at the molecular level.
Candidate profile. Mandatory requirements include a Master’s degree in evolutionary biology, bioinformatics skills, experience in working with genomic data (whole genome assembly, RNAseq), and good knowledge of phylogenetics and molecular evolution methods. Basic programming skills (Bash/Perl/Python scripting) are a prerequisite, advanced programming skills will be a plus. A high degree of initiative and motivation, and dedication to the project are also expected. There are no conditions of nationality, but as the successful candidate will be part of an international team, good English skills and capacity for teamwork are highly desirable. The successful candidate will have a genuine interest to interact with other project members working on morphological evolution and microbiome evolution in mammals.
Applications. Candidates must send electronically their application before June 30th, 2017 in the form of a single PDF file including a cover letter detailing their motivation for the project, a CV, eventually a copy of their Master thesis, and contact information of two references to frederic.delsuc@umontpellier.fr. We will review applications upon receipt. Short-listed candidates will be interviewed during the first week of July 2017 and the final decision sent shorty after.
This PhD position is part of the ConvergeAnt project (https://fdelsuc.wixsite.com/convergeant) funded by the European Research Council (ERC), which aims at investigating the complex interplay between the mammalian morphology, genome, and microbiome in a classical case of adaptive convergence driven by a highly specialized diet.
Starting date: 01/10/2017
Duration: 3 years
For further information, please contact Dr. Frédéric Delsuc (frederic.delsuc@umontpellier.fr).
