About thirteen different species of finches inhabit the Galapagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the thirteen species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six ground finch species (genus Geospiza). If the six ground finch species have evolved most recently, then which of these is the most logical prediction?
a. They should be limited to the six islands that most recently emerged from the sea.
b. The chances of hybridization between two ground finch species should be less than the chances of hybridization between two tree finch species.
c. Their genomes should be more similar to each other than are the genomes of the five tree finch species.
d. They should share fewer anatomical homologies with each other than they share with the tree finches.