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

Explanation

(a) Darwin finches/black birds (on Galapagos islands), evolved from origin seed eating features, into insectivorous & vegetarian finches in different parts of island.
(b) (i) Australian marsupials each different from the other evolved from a common ancestor but within the Australian continent. Placental mammals in Australia show adaptive radiation and appear similar to Australian marsupials.
(ii) Convergent evolution, more than one adaptive ratidation occured in isolated geographical area.