Animals that possess homologous structures probably _____.

• A. evolved from a common ancestor
• B. live in the same environment
• C. have identical DNA sequences
• D. perform the same function with those structures

Answer: (A)

Verified step by step guidance

1. Understand the concept of homologous structures: Homologous structures are anatomical features in different species that are similar in structure but may serve different functions. These similarities suggest a shared evolutionary origin.
2. Analyze the relationship between homologous structures and evolution: Homologous structures arise due to descent from a common ancestor, even if the structures have adapted to different functions over time.
3. Eliminate incorrect options: 'Live in the same environment' is not necessarily true, as species with homologous structures can inhabit vastly different environments. 'Have identical DNA sequences' is incorrect because DNA sequences can vary significantly even among species with homologous structures. 'Perform the same function with those structures' is also incorrect, as homologous structures can serve different functions (e.g., a bat's wing and a human's arm).
4. Identify the correct answer: The presence of homologous structures indicates that the species evolved from a common ancestor, as these structures are inherited and modified over time through evolutionary processes.
5. Conclude: The correct answer is 'evolved from a common ancestor,' as this aligns with the definition and evolutionary significance of homologous structures.