Which field focuses on the comparison of body structures and their variation among species?

• A. Comparative anatomy
• B. Adaptation
• C. Natural selection
• D. Evolution

Answer: (A)

Comparative anatomy investigates how body structures compare across different species and how those structures vary and relate to function and ancestry. By examining features like homologous bones that appear in related organisms but are adapted for different uses, or vestigial organs that no longer serve their original purpose, this field reveals patterns of similarity and difference that point to evolutionary relationships. That focus on examining and contrasting physical structures across species is exactly what the question is asking about.

In contrast, adaptation describes traits that improve survival or reproduction, natural selection is the process that changes trait frequencies over generations, and evolution refers to the broader pattern of change in populations over time.