What name is given to the rapid diversification of one ancestral species into many ecological forms?

Adaptive radiation is the rapid diversification of one ancestral species into many ecological forms.

It commonly occurs when organisms enter an environment with open ecological niches or when a new trait allows them to use resources in different ways. Descendant populations become specialized for different habitats, foods, or lifestyles, and reproductive isolation can eventually produce separate species.

Darwin’s finches on the Galápagos Islands are a classic example. Their common ancestor gave rise to several species with different beak shapes and feeding habits. The beaks are associated with distinct food resources, although the finches’ evolutionary history also includes competition, environmental change, and hybridization.

Adaptive radiation is different from convergent evolution. In adaptive radiation, related organisms diversify from a shared ancestor. In convergence, unrelated lineages independently evolve similar traits, such as streamlined bodies in sharks and dolphins.