Estimating diversification rates from phylogenies with extinct and extant taxa
Time: 13:15
Sebastian Höhna
Ludwig-Maximilians-Universität München
Abstract
Diversification rates are often estimated from molecular phylogenies of extant taxa by using birth-death models. The birth-death process models speciation and extinction and integrates over all extinct lineages. In theory, such the birth-death process gives unbiased estimates of speciation and extinction rates, which I also confirmed by means of simulations. However, speciation and extinction rate estimates compared between inference from fossil species diversity and molecular phylogenies of extant taxa do not agree. In this talk, I show how fossils can be included in phylogenies and the birth-death process extended accordingly to use combined data. I will present some new results using a combined phylogeny of extinct and extant taxa of crocodylomorpha to study the impact of the KPg mass extinction event on their species diversity.
Biography
I’m a computational biologist with focus on Bayesian phylogenetic inference. Natural selection by means of adaptation and genetic inheritance are key principles in evolutionary biology. Evolutionary relationships are commonly depicted by phylogenetic trees. Using phylogenetic methods we can learn about the evolutionary history of species and the processes that have contributed to present diversity. I’m developing statistical and computational methods to infer phylogenies from molecular sequence data. These methods additionally identify periods of adaptive genetic evolution at lineage or genes. Furthermore, I develop mathematical models to study macroevolutionary patterns, such as, diversification rate variation over time and among lineages and episodes of global mass extinctions.
