Question

The original birds were ________, from which the various Darwin’s finches arose.

(1) Insectivorous (2) Cactus eating

(3) Carnivores (4) Seed eating

Answer 1

option (4) seed eating

Adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches.
One famous example where adaptive radiation is seen is with Darwin's finches. The differences in geography throughout disjointed landscapes of Galapagos islands are believed to promote such diversification. Of all the varieties of finches, which were observed in the same island, Darwin found that all of them had evolved from original seed-eating finches. He explained that after originating from a common ancestral seed-eating stock, the finches must have radiated to different geographical areas and undergone adaptive changes, especially in the type of beaks. Therefore, due to the alternation in beaks gradually, some became insectivorous and some vegetarian.​​​​​​​