Wolf Eiserhardt, Associate Professor, Department of Biology - Ecoinformatics and Biodiversity, Aarhus university.
Biological diversity is distributed highly unevenly over the surface of the earth, with a striking concentration in tropical rainforests, which are said to harbour half of the world’s species on only 7-10% of its terrestrial surface. This geographic unevenness in species richness has arisen via speciation, extinction and migration over hundreds of millions of years. Phylogenetic information (the “tree of life”) can provide insights into the dynamics of these processes over time, but unlocking this information is challenging. In this talk, I demonstrate how phylogenetic insights into geographic biodiversity patterns are impeded by lack of knowledge (the “Darwinian shortfall”) and discuss two complementary solutions: firstly, using large but incomplete representations of the tree of life (so-called “megatrees”) and secondly, using carefully selected and thoroughly reconstructed individual branches of the tree of life (so-called “model groups”). I will illustrate and contrast these approaches using recent studies we conducted for seed plants (Spermatophyta) and the palm family (Arecaceae), a well-established model group for studying ecological and evolutionary dynamics in the tropics. In doing so, I will evaluate different hypotheses that have been put forward to explain the striking biological hyperdiversity of tropical rainforests.