What is adaptive radiation?

Adaptive radiation refers to the rapid evolution of species that occurs when a single lineage diversifies into a wide array of forms to exploit different ecological niches. This phenomenon typically happens when a common ancestor encounters new environments, particularly after events such as the colonization of new territories or after mass extinctions. In these scenarios, species may adapt to various resources and habitats, leading to increased biodiversity.

For instance, the classic example of adaptive radiation is observed in Darwin’s finches on the Galápagos Islands. These birds evolved from a common ancestor into multiple species, each with different beak shapes suited for distinct food sources, such as seeds, insects, or nectar. This rapid speciation is a direct response to the diverse environmental challenges presented by the different habitats they occupy.

The process contrasts with gradual evolution, which involves slow changes over extensive periods; adaptive radiation is characterized by a quick diversification that can occur across generations when opportunities for adaptation arise.