2013-2 Modelling competitive exclusion and limited dispersal in a statistical phylogeographic framework

Competitive exclusion embodies  the idea of the  first mover advantage where  species or populations arriving first at a  suitable location prevent secondary colonisation of  the already occupied site.

While adaptation  to environmental variables (e.g.,  temperature, altitude, etc.) is  essential, the presence or  absence of certain  species at a  particular location often  depends on whether  or not competing  species co-occur.   In particular,  competition could explain observed  patterns of  low genetic  and phenotypic  diversity following  rapid colonisation events in  Europe as  well as  the “progression” pattern  in the  phylogenies of species found  on various islands  along the Hawaiian archipelago. Competitive exclusion has been  absent from past quantitative analyses because of the  difficulty in designing adequate  methods for assessing its impact.  We present here a new statistical framework that  integrates competition along with limited dispersal  into a Bayesian phylogenetic model of  migration.  Using simulations,  we assess  the performance of our  approach and demonstrate its  ability to detect competition from the comparative analysis  of homologous genetic sequences using geographic information.

Stephane Guindon