The following questions refer to the evolutionary tree in the figure below.
The horizontal axis of the cladogram depicted below is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V-Z) represent various common ancestors. Let's say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.

-Which of the five species, labeled V-Z, is the common ancestor of the fewest number of species?
A) V
B) W
C) Y
D) Z

Question

The following questions refer to the evolutionary tree in the figure below.
The horizontal axis of the cladogram depicted below is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V-Z) represent various common ancestors. Let's say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.
 
-Which of the five species, labeled V-Z, is the common ancestor of the fewest number of species?
A) V 
B) W 
C) Y 
D) Z

Quizplus · Accepted Answer

Species V is the common ancestor of only one distinct species, while the other labeled common ancestors (W, X, Y, and Z) are each ancestral to multiple distinct species.

The Following Questions Refer to the Evolutionary Tree in the Figure