Diversification dynamics of Placentalia (Mammalia): integrating the fossil record with molecular phylogenies

Abstract

Understanding the historical patterns of the diversification dynamics is extremely important to several evolutionary questions. The most commonly used approaches in these studies are the fossil record and the molecular phylogenies, but both have their limitations. Analytical paleobiology provides the most direct way of investigating the evolutionary dinamic, nevertheless only a few lineages have a fossil record with the quality required for this analysis. In the other hand, the analysis of filogenetics based on molecular data have no taxonomic constraints and phylogenies of several groups are available nowadays.Recent studies indicate the need to use both approaches in order to improve the study of the evolutionary history. The goal of this project is to integrate the approaches to investigate the diversification dynamics of the 21 orders of Placentalia, as well as investigate the mechanisms that generated the patterns of diversity analysed.Specifically, I will: 1- use the fossil record to determine the diversity trajectory of the orders of Placentalia; 2- use the molecular phylogenies to investigate whether the decline of diversity (inferred from the fossil record) is more phylogenetic aggregated than the expected by chance (i.e., there is phylogenetic signal); 3- test the hypothesis that body size determines the evolutionary trajectory of the orders of Placentalia. (AU)