Understanding the diversity of life: trait correlations from micro- to macroevolutionary scales

Project description : Understanding the mechanisms that lead to biological diversity over long periods of time is one of the most important underpinnings of evolutionary biology. However, when we look at the immense diversity of life we can see several clear patterns that are surprising. Diversity is not evenly distributed across the tree of life. This suggests that the processes generating diversity are constrained: some lineages experience different rates of trait evolution and diversification than others and there are constraints on the numbers of species and on their variety of form and function. This clearly suggests genetic, ecological, developmental, or physiological limits on evolution. These constraints may be taxon specific or cut across taxa, suggesting general limits at higher taxonomic levels. Resolving the mechanisms driving these patterns will dramatically improve our understanding of the processes that determine the diversity of life.

The overall objective of the PhD is to test how correlations among traits evolve at multiple scales (intraspecific, intraclade and interclade) to shape the diversity of traits and species across the tree of life. Specifically, the first objective is to test the stability of trait correlations through time. The stability of phenotypic trait correlations may have important macroevolutionary consequences, for example by constraining the potential total phenotypic diversity within and among clades (i.e. their disparity). The second objective is to test how variation in correlations constrains (i) disparity and (ii) diversity of species among lineages.