Consider a phylogeny of metazoans.Snakes, which lack limbs, evolved from vertebrates that had legs.The limbs of snakes disappeared by _______, and the backbones of snakes are a _______.
A) convergent evolution; synapomorphy
B) an evolutionary reversal; synapomorphy
C) convergent evolution; homoplastic trait
D) an evolutionary reversal; homoplastic trait
E) an evolutionary reversal; heteroplastic trait

Question

Quizplus · Accepted Answer

Snakes losing their legs is an example of an evolutionary reversal, as they lost a trait that their ancestors possessed. The backbones of snakes are a synapomorphy, a shared derived trait that distinguishes them from other groups of animals.

Consider a Phylogeny of Metazoans