Which statement about fossils would best indicate they share ancestry with a modern species?

• A. The fossils are found in different geographic regions.
• B. The fossils are all identical in form.
• C. The fossils show no similarities to modern species.
• D. The fossils show structural similarities to the modern species, suggesting shared ancestry.

Answer: (D)

When scientists look for evidence of relatedness between fossils and a living species, they focus on structural features that are inherited from a common ancestor. If a fossil shares the same basic body-plan or bone arrangement as a modern species, that pattern indicates descent from a shared ancestor and shows how the lineage has been inherited and modified over time. The other ideas don’t provide that direct link: where fossils are found geographically doesn’t by itself prove a relationship, fossils that are identical across time are unusual and don’t necessarily connect to the present species, and fossils with no resemblance to the modern species don’t support a common origin.