|evolution of a number of divergent species from a common ancestor, each species becoming adapted to occupy a different environment. This type of evolution occurred in the Tertiary manuals and the Mesozoic reptiles|
|adaptive radiation (ə-dāp'tĭv) Pronunciation Key
The evolutionary diversification of a species or single ancestral lineage into various forms that are each adaptively specialized to a specific environmental niche. Adaptive radiation generally proceeds most rapidly in environments where there are numerous unoccupied niches or where competition for resources is minimal. See Note at adaptation.