How do vestigial structures provide evidence for evolution?

• A. They are adaptations that arise due to convergent evolution in unrelated species.
• B. They are newly developed structures that provide a selective advantage in modern environments.
• C. They are structures that have always been nonfunctional and unrelated to evolutionary history.
• D. They are remnants of features that served important functions in an organism's ancestors, indicating common ancestry.

Answer: (D)

Verified step by step guidance

1. Vestigial structures are anatomical features that have lost their original function or have reduced functionality over time. These structures are remnants of features that were functional in an organism's ancestors.
2. To understand how vestigial structures provide evidence for evolution, consider that they indicate a shared ancestry. For example, the presence of a vestigial structure in multiple species suggests that these species inherited the structure from a common ancestor.
3. Vestigial structures demonstrate how evolutionary processes can lead to changes in an organism's anatomy over generations, as certain features become less necessary for survival or reproduction in a changing environment.
4. Examples of vestigial structures include the human appendix, which is thought to have been more functional in ancestral species for digesting cellulose, and the pelvic bones in whales, which are remnants of their land-dwelling ancestors.
5. By studying vestigial structures, scientists can trace evolutionary relationships and understand how species have adapted to their environments over time, providing strong evidence for the theory of evolution.