Motility-driven fracture in biological active matter from cancer to the germline

Cancerous cells can break off from an invading tumor and colonize the rest of the body - but similar events happen in healthy developing embryos, and more dramatically, some organisms like Trichoplax adhaerens can fission into two animals by tearing themselves apart. What physical factors control the size of groups of cells that break off? How does the fluidity of the tissue control this fracture - is unjamming necessary? To what extent can these fracture processes driven by active motility be considered active escape over a barrier? Can an organism or tissue regulate its size by controlling fracture? I will discuss our group's work starting to answer these questions using computational and theoretical approaches applied to model systems ranging from cancer invasion to the formation of germline cysts.