Research seminar: Understanding mammalian diversity at a global scale with a phylogenetic and functional biogeographic approach.

Mammals have diversified during the Cenozoic and have colonised all continents and oceans. My work aims at understanding the nature and significance of the different processes leading to current geographical distributions of mammals, with a particular focus on faunal similarities between regions of the globe. I show that at recent phylogenetic scales (e.g. species), clade distributions are related to climatic affinities while at ancient phylogenetic scales (e.g. families), clade distributions seem to be driven by plate tectonic dynamics over the last 65Ma. Also, I show that the regions populated with independent mammalian faunas and experiencing the same broad climate, show evolutionary convergences at the level of entire biotas, i.e. they show high functional similarities. This is particularly the case between Australia and north temperate regions. Interestingly, I also observe patterns of phylogenetic scale disparities in the distribution of bacterial lineages living in mammalian guts. I show that host mammalian phylogeny and diet influence the distribution of independent gut bacterial lineages, and do so on vastly different time scales. Diet mostly influences the acquisition of deeply divergent microbial lineages, while host phylogeny discriminates among more recent lineages. As mammals diverged recently in comparison to bacteria, the effect of host phylogeny on recent bacterial lineages is consistent with co-diversification between host and their gut microbial communities. Taken together, my results show that using jointly phylogenetic and functional information allows us to shed new lights on our understanding of biodiversity distribution, both at the levels of macro- and micro-organism communities.

Seminario organizado por el Departamento de Biodiversidad y Biología Evolutiva del Museo Nacional de Ciencias Naturales (MNCN), CSIC.