Welcome to our website

We combine mathematics, bioinformatics and fieldwork to study questions ranging from macroevolution and macroecology to community assembly, biogeography, and conservation. We are based at the Institute of Biology at the Ecole Normale Supérieure in Paris.



What is the evolutionary history of species diversity on this planet, and where is it headed? To test hypotheses on the long-term dynamics of biodiversity, we develop models of cladogenesis, and apply these models to a wide variety of empirical phylogenies. This approach allows testing hypotheses on the tempo and modes of species diversification in absence of fossil data.
Biodiversity resilience


What are the processes underlying current biodiversity patterns? To understand the distribution and abundance of species, we study three of the most general patterns in ecology: the distribution of abundances among species, the increase in the observed number of species with increasing sample area, and the decay in community similarity with geographic distance. We also develop theory to understand the spatial distribution of phylogenetic diversity, in order to move beyond species and take into account their evolutionary history.

Microbial biogeography

Most biodiversity on Earth is microbial, yet very little is known about the spatial distribution of microorganisms. We are interested in the global biogeography of microorganisms and how it compares to that of macroorganisms. We are currently working on applying macroevolutionary approaches to the microbial world. Collaborators: Jessica Green and Brendan Bohannan, from the University of Oregon. Hélène is affiliated to the BIOBE and META centers.