[A]: Darwin's finches show a variety of beaks suited for eating large seeds, flying insects and cactus seeds.
[R]: Ancestral seed-eating stock of Darwin's finches radiated out from South American mainland to different geographical areas of the Galapagos Islands, where they found competitor-free new habitats

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark a
B. lf both Assertion & Reason are true but the reason is no t the correct explanation of the assertion, then mark b
C. If Assertion is true statement but Reason is false, then mark c
D. If both Assertion and Reason are false statements, then mark d.

Answer

A

Explanation

Drawin finches are an excellent example of the way in which the species gene pools have adapted in order for long term survival via their offspring. Finches were formed due to divergent evolution (adaptive radiation) to avoid interspecific competition. The common birds of Galapagos islands, the finches were markedly different from the finches of main land. The closely related species of finches had beak of different shapes and sizes, and adapted for feeding on completely different diets. Drawin also found that fossils of Galapagos islands are most similar to living species of South America. The food supply increases in arithmetic ratio but the population increases in geomatric ratio. With the study of this theory it struck to Drawin that there is struggle for exstence among plants and animals. This concept of competition among the living beings for their survival offered the basis for the theory of natural selection. Apparently a single ancestral group can give rise to serveral different varieties of species.