Which type of evidence for evolution is provided by the presence of hip bones in dolphins?

• A. Vestigial structures indicating common ancestry with terrestrial mammals
• B. Homologous structures shared with birds
• C. Analogous structures showing convergent evolution with fish
• D. Direct evidence of mutation in dolphin DNA

Answer: (A)

Verified step by step guidance

1. Understand the concept of vestigial structures: These are anatomical features that have lost their original function through evolution but are retained in an organism. They provide evidence of common ancestry.
2. Recognize that dolphins are mammals and share a common ancestor with terrestrial mammals. The presence of hip bones in dolphins suggests that their ancestors were land-dwelling mammals.
3. Differentiate between homologous, analogous, and vestigial structures: Homologous structures are shared due to common ancestry but may have different functions, analogous structures arise due to convergent evolution and have similar functions but no common ancestry, and vestigial structures are remnants of ancestral traits.
4. Analyze the options provided: Hip bones in dolphins are not homologous structures shared with birds, nor are they analogous structures showing convergent evolution with fish. They are vestigial structures indicating a shared ancestry with terrestrial mammals.
5. Conclude that the correct type of evidence for evolution provided by the presence of hip bones in dolphins is vestigial structures, which indicate common ancestry with terrestrial mammals.