Patterns in Evolution

Natural selection is a key mechanism in the development of diversity among organisms.  A flock of migratory birds gets divided in a storm while headed for warmer climates. Half of the flock reached the warmer climate and half of the flock lands on a new island and stays.  Over time, members of the flock that settled on the island develop characteristics that increase their rate of survival on the island.  The population on the island eventually evolves into a different species than their ancestors.  

Which of the following patterns of evolution does this represent?

Natural selection is a key mechanism in the development of diversity among organisms.  Scientist Charles Darwin studied finches (birds) on the Galapagos Islands off of the coast of South America.  He discovered that more than a dozen species evolved from a single species of finch that first populated the Galapagos Islands.

Which of the following patterns of evolution does this represent?

The hypothesis that evolutionary development is marked by isolated episodes of rapid speciation between long periods of little or no change.