Phylogenomics, micropaleontology, and molecular dating

The re-evaluation of the origin and evolution of eukaryotes is in progress. The EST approach is one of the fastest and most inexpensive ways for obtaining large number of genes in poorly studied organisms. These sequences can be then the core of phylogenomic analyses where large gene datasets are used to infer evolutionary relathionships.

In particular, these multigenes phylogenies helped in resolving the eukaryote tree into a topology with a rather small number of internally diverse taxonomic supergroups. Nevertheless, our actual picture of the eukaryote phylogeny remains poorly defined.

So far, we have obtain the first EST data for foraminiferan species and other ameoboid protists and constructed a super-matrix composed of 49 species spread throughout the eukaryotic tree and nearly 30'000 amino acids. Our results show that the supergroup Rhizaria is in fact closely related to an other supergroup, chromalveolates, possibly nested within the later. We propose an updated view for the tree of eukaryotes:



Our current project is to extend our taxa sampling with species specifically chosen for their good micropaleontological records. We are inferring a molecular time-scale for the eukaryotic tree, at the interface between phylogenomics and micropaleontology.

people working on this subject: Jan Wojciech PAWLOWSKI, Fabien BURKI.