Question

Which of the following is an example of homologous structures that provide evidence for evolution?

• A. Wings of a bird and wings of an insect
• B. Forelimbs of a human and wings of a bat
• C. Fins of a fish and flippers of a whale
• D. Stingers of a bee and spines of a porcupine

Hint:

Distinguish homologous structures (same origin, different functions) from analogous structures (different origins, similar functions). Homologous structures, like vertebrate forelimbs, support common ancestry.

Answer 1

The Correct Option is B

Homologous structures are organs or structures in different species that have a similar anatomical origin (derived from a common ancestor) but may serve different functions due to divergent evolution. The forelimbs of a human and the wings of a bat are homologous because they share a common skeletal structure (e.g., humerus, radius, ulna, and digits), indicating they evolved from a common tetrapod ancestor, even though they serve different functions (manipulation in humans, flight in bats).
The other options are incorrect:
- Wings of a bird and wings of an insect: These are analogous structures, as they serve the same function (flight) but have different anatomical origins (feathers vs. chitinous wings).
- Fins of a fish and flippers of a whale: These are analogous structures, as they serve similar functions (swimming) but arise from different embryonic tissues (fish fins from mesoderm, whale flippers from tetrapod limb buds).
- Stingers of a bee and spines of a porcupine: These are not homologous, as they have different origins and functions (bee stingers are modified ovipositors, porcupine spines are modified hairs).
Thus, the forelimbs of a human and wings of a bat are homologous structures providing evidence for evolution.