A paleontologist discovers fossils of extinct mammals in South America that strongly resemble living armadillos found in the same region. Based on Darwin’s reasoning, what is the most likely scientific interpretation of this evidence?

• A. Fossils are unrelated to modern organisms because extinction prevents comparison
• B. Similar environments always produce identical organisms without evolutionary change
• C. Living armadillos are direct unchanged survivors of prehistoric species
• D. Modern species may have descended from earlier related forms that changed over time

Answer: (D)