(a) Explain adaptive radiation with the help of a suitable example. (b) Cite an example where more than one adaptive radiation has occurred in an isolated geographical area. Name the type of evolution your example depicts and state why it is so named.

(a) The process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas or habitats is called adaptive radiation. For example, alterations in beaks of finches on Galapagos islands. (ii) An example where more than one adaptive radiation has occurred in an isolated geographical area is Australian Marsupials. Here, a number of different marsupials evolved from an ancestral stock within the isolated Australian island but adapted to different habitats e.g., Tasmanian wolf (marsupial) and a placental wolf (placental mammals). The above example depicts convergent evolution as these marsupials show the development of similar adaptive functional structures in unrelated groups of organisms.