The discovery of a biological switching valve provides an example of a mechanism that evolved in nature long before its invention by man and could inspire alternative valve technologies.

Functional recapitulation of a likely evolutionary gain in gene expression shows that two genes are sufficient to switch mesoderm cell internalization from stochastic cell ingression to coordinated epithelial invagination.

Hairless emerged as an evolutionarily novel regulatory protein that replaced an ancestral paradigm of direct co-repressor recruitment by Suppressor of Hairless, its partner transcription factor in the Notch signaling pathway.

Sexual differentiation controlled by sex-specific mRNA splicing evolved in a step-wise manner in insects.