Speaker
Description
The origin of multicellularity was one of the most significant innovations in the history of life. Our understanding of the evolutionary processes underlying this transition remains limited, however, mainly because extant multicellular lineages are ancient and most transitional forms have been lost to extinction. We bridge this knowledge gap by evolving novel multicellularity in vivo, using the 'snowflake yeast' model system. In this talk, I'll focus on our most Multicellularity Long-Term Evolution Experiment (MuLTEE), in which we've put snowflake yeast through ~5,000 generations of selection. We'll examine how snowflake yeast evolve to be ~20,000x larger, and 10,000x biophysically tougher than their ancestors through a clever change in the way that cells interact within the group. Through a combination of multicellular biophysics and synthetic biology, we'll examine how two key steps in this transition: a multicellular life cycle and heritability of multicellular traits, arise 'for free'. If time permits, we'll examine early steps in the evolution of cellular differentiation. Our approach, which allows for the study of macroevolutionary processes over microevolutionary timescales, demonstrates that multicellularity is less evolutionarily constrained than previously thought.
