If the outgroup species X has the black state of a character and the ingroup spe
ID: 216947 • Letter: I
Question
If the outgroup species X has the black state of a character and the ingroup species A, B, and C have the white state, which of the statements below is true? A B CX Select one: O a. It is ambiguous whether white or black is derived. O b. The black state must be plesiomorphic. O c. The white state is a synapomorphy for the ingroup. X O d. Species C should have the black state. e. Illinois is a red state. Your answer is incorrect. The correct answer is: It is ambiguous whether white or black is derived.Explanation / Answer
Apomorphy : A derived (advance) character state (with reference to another ancestral state) is called apomorphy.
Synapomorphy : when a derived character state is shared by two or more taxa, then it is called Synapomorphy.
Plesiomorphy : an ancestral character state (with reference to another derived state) is called Plesiomorphy.
Symplesiomorphy : when an ancestral character state is shared by two or more taxa, then it is known as Symplesiomorphy.
Conclusion : From the given phylogenetic tree it is clear that the which character state is possessed by A, B and C species but black character is possessed by only the outgroup species X. What is the character state of the common ancestor of outgroup as well as ingroup is not clear from the phylogenetic tree. Now we can't determine what is the apomorphic character state or plesiomorphic character state. So, it is ambiguous whether white or black is derived. Option 'a' is the right choice here.