Speaker: Raphael Forien, CMAP – École Polytechnique, France
Title: Gene flow across geographical barriers
Abstract: Barriers to gene flow are physical or biological obstacles which locally reduce migration and genetic exchanges between different regions of a species’ habitat. Genetic relatedness between individuals can be deduced from the distribution of the positions of their ancestors back in time. In the presence of obstacles to migration, these ancestral lineages can be modelled by simple random walks outside of a bounded region around the obstacle. We present a continuous real-valued process which is obtained as a scaling limit of these random walks, and we give several constructions of this process.