Question

Based only on the graphic above, which mammals likely shared a most recent common ancestor?
Responses
A The cat and the bat based on average size and appearance of organism’s front limbThe cat and the bat based on average size and appearance of organism’s front limb
B The horse and the whale based on the overall size of the organismThe horse and the whale based on the overall size of the organism
C The human and the cat based on the higher occurrence of bone shape similaritiesThe human and the cat based on the higher occurrence of bone shape similarities
D The horse and the bat based on the number of phalanges on the front limb of each organismThe horse and the bat based on the number of phalanges on the front limb of each organism

Answer 1

C — The human and the cat. Their forelimb bones (humerus, radius/ulna, carpals, metacarpals, phalanges) show the most similar shapes and arrangement in the diagram, indicating a more recent common ancestor.