Macroevolution

Diversification and historical biogeography

Current species numbers vary widely across regions of the world and across biological groups. For example, we can see that species richness generally increases from the poles to the equator, a pattern called the Latitudinal Diversity Gradient.
These diversity patterns result in part from processes happening over millions of years: speciation (the formation of new species), extinction (the disappearance of species) and dispersal (the movement in and out of a region). We try to estimate how each of these processes has varied through time, space and biological groups. In doing so, we also integrate phenotypic traits, ecological information,  and geological changes to explain these variations.
As we lack a time-machine to observe where and how species lived millions of years ago, or what they looked like, we infer this information by combining observations of species nowadays with phylogenetic trees describing the evolutionary history of these species. We mainly focus on the evolutionary history of Lepidoptera (butterflies and moths) with a special interest in the origin of the Latitudinal Diversity Gradient and of Neotropical biodiversity. 

Macroevolution of phenotypes

Insects vary greatly in shape, color and size. But why are some groups brighter than others? Or bigger than others? To study the evolution of phenotypes in Insects we work with two approaches.
First we use geometric morphometrics to quantify variation in butterfly wing size and shape. These morphometric tools allow us to “draw” butterfly wing contours and compare them to explore how the shapes and sizes vary across species and how they have evolved over time.
Our second approach makes use of insect bulk samples spread on white background to automatically extract body size information. To achieve this, we are developing AI-assisted tools to automatically detect insects on pictures and extract their contours for identification and body size estimations. This method allows us to rapidly process hundreds of images, each of them containing up to hundreds of insects.