Which term describes a physical feature that no longer serves a function?

Which term describes a physical feature that no longer serves a function?

• A. Vestigial organ
• B. Fossil evidence
• C. Geographic isolation
• D. Species

Answer: (A)

Vestigial structures are physical features that come from an ancestor but have lost their original function over time. A vestigial organ persists as a reduced or useless remnant because the trait no longer provides a selective advantage in the organism’s current environment. Classic examples include the human appendix and coccyx, which once had important roles in digestion or tail support for related species but are now largely nonfunctional. The idea behind vestigial features is that evolution tinkers with traits, and if a trait becomes less useful or costly to maintain, natural selection may allow it to degenerate. Fossil evidence refers to preserved remains that inform us about past life, not about a current feature that has lost its function. Geographic isolation describes a mechanism that can lead to speciation, not a specific feature. A species is a group of organisms that can interbreed, which is a broader concept than a nonfunctional trait.

Vestigial structures are physical features that come from an ancestor but have lost their original function over time. A vestigial organ persists as a reduced or useless remnant because the trait no longer provides a selective advantage in the organism’s current environment. Classic examples include the human appendix and coccyx, which once had important roles in digestion or tail support for related species but are now largely nonfunctional. The idea behind vestigial features is that evolution tinkers with traits, and if a trait becomes less useful or costly to maintain, natural selection may allow it to degenerate.

Fossil evidence refers to preserved remains that inform us about past life, not about a current feature that has lost its function. Geographic isolation describes a mechanism that can lead to speciation, not a specific feature. A species is a group of organisms that can interbreed, which is a broader concept than a nonfunctional trait.