Which of the following is considered strong evidence supporting the theory of common descent through natural selection?

• A. Homologous structures observed in different species
• B. Seasonal changes in animal behavior
• C. Random mutations that do not affect phenotype
• D. The presence of analogous structures in unrelated organisms

Answer: (A)

Verified step by step guidance

1. Understand the concept of common descent: Common descent refers to the idea that all living organisms share a common ancestor. Evidence supporting this theory often involves similarities in structure, genetics, or development among different species.
2. Define homologous structures: Homologous structures are anatomical features that are similar in structure and position but may serve different functions in different species. These similarities suggest a shared evolutionary origin.
3. Contrast homologous structures with analogous structures: Analogous structures are features that serve similar functions but do not share a common evolutionary origin. They arise due to convergent evolution, not common descent.
4. Evaluate the other options: Seasonal changes in animal behavior are influenced by environmental factors and do not directly support common descent. Random mutations that do not affect phenotype are neutral and do not provide evidence for natural selection or common descent.
5. Conclude that homologous structures observed in different species are strong evidence for common descent through natural selection, as they indicate shared ancestry and evolutionary processes.