What is true of the flightless cormorants of the Galápagos Islands?
A) They are descendants of the same common ancestor that gave rise to the unique finches of these islands.
B) They are close relatives of flightless cormorants from the Americas.
C) If they are still able to breed successfully with flying cormorants, it would probably be with North American cormorants, rather than with South American cormorants.
D) Flightless cormorants on one island have restricted gene flow with those on other islands, which could someday lead to a macroevolutionary event.
E) Their DNA has low levels of sequence homology with the DNA of flying American cormorants.
Answer: D