A 14th species that descended from the original ancestral finch, the Cocos Island finch, is endemic to its namesake island, located 550 km off Costa Rica. The Cocos Island finch is genetically much more similar to the tree finches than is the vegetarian finch, yet it is classified in its own genus Pinarolaxias. Moreover, the Cocos Island finch and the vegetarian finch are the two finch species that are most genetically different from the ancestral Galápagos finch. Thus, if classification is to reflect evolutionary relationships, the vegetarian finch should
A) remain in the genus Camarhynchus.
B) be switched from Camarhynchus to Certhidea.
C) be switched from Camarhynchus to Pinarolaxias.
D) be switched from Camarhynchus to Geospiza.
E) be placed in its own genus.

Question

Quizplus · Accepted Answer

Based on the information provided, it is clear that the genetic distance between the Cocos Island finch and the vegetarian finch is greater than the distance between either of these species and the ancestral Galápagos finch. Furthermore, the Cocos Island finch, despite its genetic similarity to the tree finches, is classified in its own genus. Therefore, it can be inferred that the vegetarian finch should also be placed in its own genus, separate from Camarhynchus, Certhidea, and Geospiza.

A 14th Species That Descended from the Original Ancestral Finch