Genomic divergence and the speciation continuum in the adaptive radiation of Timema stick insects
Friday seminar by Moritz Muschick from University of Sheffield
The idea of speciation as being a slow and continuous process is a prevailing concept in evolutionary biology, but some theoretical models predict the possibility of a rapid transition through the intermediate phases during speciation. In the adaptive radiation of Californian stick insects of the genus Timema speciation and build up of genetic isolation is influenced by geographical distance between populations, differences in climate, as well as by adaptation to different host plants. In this talk I present an attempt to elucidate the nature of the speciation continuum in this radiation. We use a genotyping-by-sequencing approach on over 100 populations of 11 species of stick insects representative of the ecological diversity of the group. We estimate phylogenetic relationships and genetic admixture between populations and combine our findings with experimental estimates of reproductive isolation and host adaptation. Our results provide a refined understanding on the speciation continuum and its ecological basis in Timema stick insects.
University of Sheffield