[Campbell Biology P.609] According to the text, what is a key distinction between a paraphyl... | Practice Question

According to the text, what is a key distinction between a paraphyletic group and a polyphyletic group, regarding their most recent common ancestor?

  • A: In a paraphyletic group, the common ancestor is always part of the group, whereas in a polyphyletic group, the common ancestor is not part of the group.
  • B: Paraphyletic groups include all descendants, while polyphyletic groups include only distantly related species.
  • C: Both paraphyletic and polyphyletic groups exclude their most recent common ancestor, but for different reasons.
  • D: A paraphyletic group is a clade, while a polyphyletic group is not.

Explanation

The text explicitly states: 'Note that in a paraphyletic group, the most recent common ancestor of all members of the group is part of the group, whereas in a polyphyletic group the most recent common ancestor is not part of the group.' This is the fundamental distinction.