Species A and B are sister species.Species C and D are also sister species.The lineage leading to species A and B diverged from the lineage leading to species C and D at node 1 of a phylogenetic tree.Prior to node 1, the lineage leading to species E diverged from the lineage leading to species A, B, C, and D at node 2.Which grouping is not monophyletic?
A) Species A and B
B) Species C and D
C) Species A, B, and C
D) Species A, B, C, and D
E) Species A, B, C, D, and E

Question

Quizplus · Accepted Answer

If we remove species C from the grouping of A and B, it becomes a paraphyletic group, not including the common ancestor of all three species. Therefore, species A, B, and C are not monophyletic. The other groups are monophyletic because they include all descendants of their common ancestors.

Species a and B Are Sister Species