question_answer

(i) Write your observations on the variations seen in the Darwin's finches shown below.

(a)

(b)

(c)

(d)

(ii) How did Darwin explain the existence of different varieties of finches on Galapagos islands?

Answer:

(i) Darwin's finches show variations in their beaks due to adaptation to different food habits.

(ii) Darwin observed that there were many varieties of finches in the Galapagos island and all varieties had evolved on the island itself 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 area and undergone adaptive changes especially in the type of beaks. Therefore, due to the alternation in beaks gradually, some became insectivorous and some vegetarian. Living in isolation for long, the new kinds of finches emerged that could function and survive in the new habitat.