The evolution of multicellularity
Multicellularity has evolved dozens of times across the tree of life, including more than 50 times in green algae alone! Why has multicellularity evolved so many times, and what molecular and evolutionary processes shape these transitions?
During my PhD, I found that plastic responses to the environment may be key intermediate stages shaping the evolution of multicellularity in the volvocine algae. My research program builds upon this framework and examines how interactions between genes, development, and the environment shaped the evolution of multicellularity.
Primary research topics
Developmental plasticity
I examine how environmental stress induces the development of somatic cells in a species that is typically undifferentiated. I’m working to understand how these plastic responses to the environment evolve during the transition from environmental regulation of cellular state to developmental regulation of cellular state.
Molecular mechanisms
I’m examining the molecular mechanisms underlying the evolution of differentiated multicellularity. I’m funded by the National Science Foundation to study the changes in gene expression that occur during the development of plastic somatic cells in Eudorina and whether these same pathways regulate the development of somatic cells in closely related species.
Genetic assimilation of somatic cells
I proposed that obligate somatic differentiation may have originated as a plastic response to the environment that repeatedly came under developmental-genetic control through genetic assimilation.
I am currently using experimental evolution to test whether somatic differentiation can evolve through genetic assimilation in Eudorina elegans.
Evolutionary transitions in individuality
Nested hierarchical structure is one of life’s most familiar properties. Groups of genes make up simple cells, groups of prokaryotic cells make up eukaryotic cells, and groups of eukaryotic cells make up eukaryotic multicellular organisms. Each new level of hierarchical organization evolves through an evolutionary transition in individuality, as a group of individuals evolves into a new kind of individual (a new level of hierarchical organization).
I study how new levels of hierarchical organization arise. I focus on the transition to multicellularity but I also work on hominin cultural evolution.
Volvocine algae biology
The volvocine green algae are often used as a model system to study the evolution of multicellularity. I study their biology and natural history. I’m also working to aiming to new species of volvocine algae.