I believe the reason for this would be geographical evolution. Different ecosystems cause the finches to evolve differently over time. Also, since the finches on the Galápagos Islands are closer to the one in South America, it is likely that finches from there (South America) could have moved to the islands, contributing to the evolutionary process.
The Constitution divides powers between the federal government's branches. The Constitution creates a structure that limits the powers of our government.
