The figure below shows the vertebrates and arthropods to be distantly related, yet each has features, like limbs and jaws, seen in no other groups.
How can such an obvious similarity be discounted in favor of embryological development as a basis for classification?

Question

The figure below shows the vertebrates and arthropods to be distantly related, yet each has features, like limbs and jaws, seen in no other groups. 
How can such an obvious similarity be discounted in favor of embryological development as a basis for classification?

Quizplus · Accepted Answer

Embryological development provides evidence for common ancestry because embryos are securely protected during development and have little need to evolve, allowing shared inherited features to indicate a common ancestor. Limbs and jaws, while appearing similar between distantly related groups like vertebrates and arthropods, may have been acquired from a common ancestor but later lost by other groups. The decision to overlook certain features, as stated in option A, is not accurate in terms of the scientific process of classification. Option B is also incorrect as it suggests that limbs have been lost by certain groups, rather than never evolved in the first place. Option D is not well-supported as not all animals with body cavities have limbs in their embryos, and the degeneration of limbs is not the only explanation for their absence.

The Figure Below Shows the Vertebrates and Arthropods to Be