Question

Explain how looking at the arm and leg bones of different animals shows that they share a common ancestor. Write your answer in 1-2 sentences.

(2 points)

Answer 1

The arm and leg bones of many animals share the same basic arrangement of bones (for example humerus, radius/ulna, wrist and finger bones) even though they are modified for different uses like walking, flying, or swimming. This structural similarity (homology) shows these limbs were inherited from a common ancestor.