Based on the Above Diagram and Other Information from Your

Multiple Choice

Based on the above diagram and other information from your text, what is the most likely (e.g., most parsimonious) explanation for the evolution of flight in vertebrates?

A) The common ancestor of all terrestrial vertebrates was wingless and wings evolved independently three different times: in bats, in pterosaurs and in the common ancestor of birds and dinosaurs.
B) Wings evolved once in vertebrates (e.g., the common ancestor of all terrestrial vertebrates had wings) and wings were subsequently lost in all but three lineages: bats, pterosaurs and birds.
C) The common ancestor of all terrestrial vertebrates was wingless and wings evolved independently three different times: in bats, in pterosaurs and in birds.
D) The common ancestor of all terrestrial vertebrates was wingless and wings evolved independently two different times: once in bats and once in the common ancestor of birds, pterosaurs and dinosaurs.