How do darwin' s finches illustrate adaptive radiation ?

Explanation

Darwin observed that there were many varieties of finches (small black birds) on the same island. All the varieties. he concluded, evolved on the island itself. All the varieties of finches were evolved from the original seed cating variety. Many other forms with altered beaks arose, enabling them to become insectivorous and vegetarian finches. This process of evolution in a given geographical area starting from a point and literally radiating to other geographical habitats is an example of adaptive radiation.