Fracture and buckling are typically understood as signs of mechanical failure in materials. In this talk, I will show how, in living systems, these instabilities are instead employed as productive mechanisms. I will show how mechanical fracture of the cardiac extracellular matrix guides morphogenesis in the developing heart, and how fracture more generally emerges as a unifying principle across morphogenetic processes. I will then turn to malaria, showing how parasite-mediated cytoadhesion to the endothelium induces mechanical buckling of infected red blood cells, leading to interdigitated contacts that strengthen anchoring and promote sequestration. I will show how similar interdigitated architectures arise across biological systems to increase structural stability, including the heart myocardium itself.