Biological systems face constant perturbations, yet often manage to produce invariable developmental phenotypes. Developmental robustness is a property observed across phyla and recent work in yeast, animals and plants has just started revealing its genetic basis.

Mestek Boukhibar and Barkoulas highlight aspects related to the definition of developmental robustness and discuss some underlying mechanisms. They piece together examples from different systems to advocate the importance of studying the phenotypic variance, rather than averages of developmental traits, which is commonplace in biology.