Enrico Sandro Colizzi

@escolizzi.bsky.social

1420 Followers 824 Following

Tenured scientist @INRIA, Lyon. Studying how microbes evolve new stuff with computer simulations.

tree of bacterial and archaeal life, showing that each major clade has reported examples of multicellular organisations, including biofilms, filaments, fruiting bodies, motile aggregates, etc.
An overview of bacterial multicellular formations: biofilms, filaments, free-floating aggregates, motile collectives and fruiting bodies. For each form, we mention an analogous eukaryotic multicellular form (respectively animal epitelia, filaments in fungi, Volvox, Dictyostelium/social animals, Dictyostelium and other slime moulds)
Re-playing the evolutionary steps from the unicellular ancestors to a multicellular group that reproduces through propagules: the adhesion mechanism of the ancestor becomes co-opted (incorporated) in the multicellular life-cycle.
Following a single cell within a cluster - as it transition from high adhesion and migratory to down-regulating adhesion and dividing - thus forming a propagule. The cell then divides and the two offspring adhere to each other and migrate as a small offspring cluster.
a multicellular cluster releases a bunch of single-cell propagules upon reaching a food patch.
When resources are more homogeneously distributed, the system evolves unicellular solutions, when resources are patchy and far apart, multicellular life cycles evolve, including propagules and for high resource heterogeneity group splitting.
A multicellular cluster that leaves behind a multicellular propagule - that is, multiple cells that adhere to each other but not to the parent.
A simulated multicellular cluster traverses the field foraging and leaving behind a single cell propagule, which after some time divides and forms a cute little 2-cell offspring.
Simulated unicellular organisms searching for resources (red, resources are brown spots) and dividing (blue).
Simulated multicellular aggregates foraging and dividing.