As embryos,baleen whales have teeth and also have two nostrils directly above their mouth.Before birth,however,the teeth are reabsorbed,and the nostrils migrate and fuse to become the blowhole.What does this observation suggest about the ancestry of these whales?
A) Baleen whales descended from an aquatic ancestor that breathed through an elongated snout, much like the modern alligator does today.
B) Baleen whale ancestors lived in habitats where the potential for mutation was relatively high; early abnormalities during embryonic development are later corrected before birth.
C) Baleen whales evolved from a terrestrial mammalian ancestor and share common inherited developmental features.
D) Modern terrestrial mammals are descended from the same marine mammal ancestors that gave rise to modern whales.

Question

Quizplus · Accepted Answer

The observation suggests that baleen whales share inherited developmental features with their terrestrial mammalian ancestors. The fact that their teeth are reabsorbed and their nostrils migrate and fuse to form the blowhole is an example of how baleen whales retain developmental features from their ancestors, despite adapting to an aquatic lifestyle. This is consistent with the theory of evolution by descent with modification, which suggests that species evolve from a common ancestry and retain traits from their ancestors.

As Embryos,baleen Whales Have Teeth and Also Have Two Nostrils