Question

Cardueline finches can be found in many areas of the world, including North America and Asia. Hawaiian honeycreepers, which are found only in Hawaii, have been found to have DNA commonalities with this group of finches that indicate they have a common ancestor. Which mechanism might have led to the appearance of the Hawaiian honeycreeper?
anatomical isolation
temporal isolation
geographical isolation
behavioral isolation

Answer 1

Geographical isolation.

An ancestral cardueline finch likely colonized Hawaii and became isolated from mainland populations (allopatric speciation). With no gene flow, founder effects, drift and natural selection produced the diverse Hawaiian honeycreeper species.