Darwin's Finches

Why are the finches on different islands so different?

The difference between where the finches evolved from all started from the finches diversifying into many different forms and adapting to their surroundings because they flew to different islands that offered more food for them to be able to survive (http://ncse.com/files/pub/evolution/excerpt--evolution--fb.pdf).From year to year the weather on Galapagos Islands changes dramatically which has a huge effect on the finches diet. Certain finches can only eat seeds while other can eat bigger foods like plants.When the weather changes, it changes the availability of certain foods which led to the conclusion of how and why the finches diversified onto many different islands (http://www.pbs.org/wgbh/evolution/library/01/6/l_016_01.html). About two-three million years ago there weren't as many islands as there are today. New islands developed from the eruption of volcanoes and over time those new islands climates started to cool and changed the vegetation on certain islands which led to the conclusion of how certain finches diversified there because of the differences between the vegetation (http://edoc.bbaw.de/volltexte/2009/1204/pdf/VII_03_Grant.pdf).