Match List-I with List-II

Choose the correct answer from the options given below.

(A)-(IV), (B)-(III), (C)-(II), (D)-(I)

The correct answer is Option (2) → (A)-(IV), (B)-(III), (C)-(II), (D)-(I)

A. Homology is based on divergent evolution .Homology indicates common ancestry. They perform different functions but  have similar anatomical structure –examples are vertebrate hearts or brains. In plants also, the thorn and tendrils of Bougainvillea and Cucurbita represent homology. Whales, bats, Cheetah and human (all mammals) share similarities in the pattern of bones of forelimbs. Though these forelimbs perform different functions in these animals, they have similar anatomical structure – all of them have humerus, radius, ulna, carpals, metacarpals and phalanges in their forelimbs. Hence, in these animals, the same structure developed along different directions due to adaptations to different needs.

B. Analogy is based on convergent evolution.  Wings of butterfly and of birds look alike. They are not anatomically similar structures though they perform  similar functions. Hence, analogous structures are a result of convergent evolution - different structures evolving for the same function and hence having similarity. Other examples of analogy are the eye of the octopus and of mammals or the flippers of Penguins and Dolphins. One can say that it is the similar habitat that has resulted in selection of similar adaptive features in different groups of organisms but toward the same function: Sweet potato (root modification) and potato (stem modification) is another example for analogy.

C. Vestigial organs are structures that have reduced in size or lost their original function during the course of evolution. They are remnants of organs or structures that were functional in the ancestral species but have diminished or no apparent function in the current species. In humans :The nictitating membrane (or the third eyelid) is vestigial; it's a small, undeveloped fold of tissue in the inner corner of the eye. Tail vertebrae are vestigial remnants of a tail present during early human embryonic development.

D. Evolution for Darwin was gradual while deVries believed mutation caused speciation and hence called it saltation (single step large mutation).