
Some whales have an underdeveloped hipbone. The hip bone is present in the anatomy but does not have any particular function in the whales' locomotion.
The presence of this vestigial hip bone in a ...
(Continued below)
... whale suggests that
A. the same homologous structure may be found in humans.
B. a mutation in the whales' DNA caused the formation of a useless skeletal structure.
C. the whales may acquire the ability to live on land before the end of their lifetime.
D. the hip bone may have played an important role in the whales' ancestors locomotion.

The answer to that question is probably D. the hip bone may have played an important role in the whales' ancestors locomotion. [ The presence of a vestigial organ suggests a shared ancestry with ...
(Continued below)