Adaptive radiation refers to the evolution of the multiple species from one ancestral species. The force which drives the formation of new species is the change of natural environment like the availability of resources, niche, and many other related changes.
The species adapt themselves to these changes and get transformed into new species.
The formation of a variety of species of finches on the Galapagos island is an example of adaptive radiation. The species formed as a result of the food resources they received on the island.
