PhD defence Raphaël Scherrer
On the multiple facets of species diversification
Investigations into micro- and macroevolutionary shenanigans
Evolution explains how species change and diversify, yet many details of how new species arise and persist remain unresolved. In this thesis, I combine simulation data, field studies and comparative evidence to better understand the processes shaping biodiversity across time scales and across evolutionary lineages. My work is an assemblage of studies addressing different aspects of the problem of the diversification of species. In one chapter, I show that when species are born, parts of their DNA is not expected to diverge from their sister species, contrary to common expectations. In another, I show that the ability of organisms to adjust their behavior to their environment affect the chances that new species will be formed. I also look at the potential for adaptation to climate change in species interacting with "facilitator" species in their ecosystem, at the reasons why the tree of life is asymmetrical, and, using empirical data, I study the pace of evolution of plumage coloration in the iconic birds-of-paradise, and quantify evolutionary divergence among populations of Caribbean lizards.