What Does the Grants' Study of Medium Ground Finches Tell

Multiple Choice

What does the Grants' study of medium ground finches tell us about evolution by means of natural selection?

A) New species cannot form.
B) A new species can form only when natural selection operates consistently in one direction for a few million years.
C) Evolution can change only single traits within a species.
D) New species normally take thousands to millions of years to arise because natural selection pressures operate in fits and starts.