In a comparison of birds with mammals, having four appendages is
A)a shared ancestral character.
B)a shared derived character.
C)a character useful for distinguishing birds from mammals.
D)an example of analogy rather than homology.
E)a character useful for sorting bird species.

Question

Quizplus · Accepted Answer

Having four appendages is a shared ancestral character because it is a trait inherited from a common ancestor of both birds and mammals. Both groups of organisms have four appendages because they share a common ancestor that also had four appendages.

In a Comparison of Birds with Mammals, Having Four Appendages