Question

Organismal biologist Neil Shubin wrote a book called "Your Inner Fish" to describe the evolutionary history of the human body and how it compares to other animals. Human adults do not have a notochord, tail, or pharyngeal slits, and yet we are still classified as chordates along with fish. Why?

Answer 1

Humans are still classified as chordates despite not having a notochord, tail, or pharyngeal slits because these features are present during the embryonic stages of human development.

Step-by-step explanation:

In biology, humans are still classified as chordates despite not having a notochord, tail, or pharyngeal slits because these features are present during the embryonic stage of human development.

During embryonic development, human embryos do have a notochord, tail, and pharyngeal slits. These features are homologous to the structures found in other chordates.

However, as human embryos further develop, the notochord is replaced by the vertebral column, the tail regresses, and the pharyngeal slits develop into other structures such as the jaw and inner ear.