Macroevolutionary studies of trait evolution are incomplete without the integration of speciation and extinction rates. The frequency of a character state on the tips of a phylogenetic tree is not only the result of the trait change per se but is also a function of lineage diversification if the character state is linked to speciation and extinction rates. In this talk, I will show three different examples of trait evolution linked to diversification.

Measuring cell-generated forces and tissue mechanical properties in vivo and in situ has proven very difficult. For this reason, our understanding of how feedback loops between biochemical signaling and mechanics contribute to robust multicellular morphogenesis is still poor. To address this limitation, I helped develop a technique based on ferrofluid droplets which allows to measure multiple mechanical parameters at time- and length-scales relevant for embryonic development.

The nucleus is extensively studied for its role in gene expression. However, growing evidences indicate that the biophysical properties of this organelle participate in cellular functions such as cell migration and pathogen killing; two processes critical for immune response. In this talk, I will describe our discovery of how immune cells undergoing confined migration squeeze their nuclei through narrow pores by forming a dense perinuclear actin network.

Force generation by actin assembly shapes cellular membranes. The mechanisms that govern the organization of cytoskeletal complexes to produce directional force in cells are not understood, particularly in the localized membrane deformations required for membrane trafficking. An experimentally constrained multiscale model shows that a minimal branched actin network is sufficient to internalize endocytic pits against membrane tension. Around 200 activated Arp2/3 complexes are required for robust internalization.

Mammalian taxonomic and ecological recovery following the K-Pg mass extinction event
By: Jordan Claytor (Wilson Lab)

Nighttime atmospheric oxidation of floral scent impacts the ability of hawkmoths to locate a floral scent source
By: Jeremy Chan (Riffell Lab)