Coevolved

Coevolved is the past tense of coevolve, a term used to describe the evolutionary process by which two or more species reciprocally affect each other’s evolution. In coevolution, genetic changes in one lineage alter the selective environment for its partner, prompting further adaptations in that partner. This mutual influence can occur in mutualistic, antagonistic, or neutral interactions and may unfold over ecological timescales or longer.

Evidence for coevolution includes congruent phylogenies of interacting groups, repeated matches between traits that suggest reciprocal adaptation, and experimental demonstrations where altering one partner changes the evolutionary trajectory of the other. Coevolution is distinct from convergent evolution, which involves unrelated lineages developing similar traits independently due to similar environments rather than direct reciprocal influence.

Prominent examples span various ecological contexts. In mutualisms, flowering plants and their pollinators often show coadapted traits such as floral morphology and pollinator foraging structures, or plant scent and pollinator behavior. The fig–fig wasp and the yucca moth–yucca plant pairs are classic case studies of highly specialized mutualisms. In antagonisms, host–parasite and predator–prey interactions can drive ongoing adaptive changes, such as bacterial resistance to phages and phage counter-adaptations, or defensive traits in prey and corresponding offensive traits in predators.

Because ecological communities vary across environments, coevolution can be localized to specific species pairs or diffuse across networks of interacting species. Understanding coevolved relationships helps explain how interactions shape biodiversity and trait diversity within ecosystems.