Using the Rate of Change That the Grants Observed in the Medium

Multiple Choice

Using the rate of change that the Grants observed in the medium ground finch, and assuming a selection event only occurs once every century, how rapidly would you predict that a species of finch like the large ground finch could evolve?

A) It would take millions of years for only beak size to evolve.
B) The medium ground finch could evolve into the large ground finch in 20 years.
C) Natural selection could produce a new species of ground finch in a few thousand years.
D) Because selection generally pushes constantly in one direction, a new species of ground finch could evolve in a single century.