The evolutionary process that is being modeled is natural selection.  As time went on, the beaks on finches changed significantly.  Although only two other types of beaks are shown here, a plethora of different beak sizes became present.  The initial beak made it difficult for the finches to exploit multiple food sources, but over time different beak sizes were able to thrive in different environments.  I chose this evolutionary process to model because I was inspired by the Galapagos Island presentation that I attended at Hofstra University.  The bigger beak allowed for the exploitation of other dietary supplements while the smaller beaks allowed the finches to obtain food in smaller spaces.  The evolution was able to occur because finches that were able to survive reproduced.  The finches that were inadequate at obtaining food were not able to survive and pass their traits on.  The cause for the variation in finch beak sizes all originates from the fact that there was competition for food and some beaks were advantageous to have while others were not.