Homologous structures are anatomical features that are similar in structure but may serve different functions in different species. These structures are often cited as evidence for the process of natural selection, as they suggest a common ancestry.
Let’s examine the options provided:
- a) The wings of a bird and the wings of a bat: These are homologous structures. Both are modified forelimbs that have evolved to serve the function of flight, despite their different appearances.
- b) The flippers of a whale and the arms of a man: These are also homologous structures. Both are derived from the same basic limb structure found in their common ancestor, but they have evolved to serve different functions—swimming in the case of the whale and manipulation in the case of humans.
- c) The wings of a butterfly and the wings of a bird: These are not homologous structures. While both are used for flight, they evolved independently and do not share a common ancestral origin. The wings of a butterfly are made of chitin and are part of the insect’s exoskeleton, whereas the wings of a bird are modified forelimbs with bones, muscles, and feathers.
Therefore, the correct answer is c) The wings of a butterfly and the wings of a bird, as they are not examples of homologous structures.