What's "Natural" on the Galapagos Islands?

In geologic years, the Galapagos Islands are infants. Located on the perpetually moving Nazca tectonic plate, the islands were formed through repeated volcanic activity. Layer by layer, the islands have risen off the ocean floor, forming a chain that is approximately five million years old. Find out more in this piece written by David Bernstein and narrated by Nicholas Breyfogle. (A text version of this piece is available at http://origins.osu.edu/connecting-history/what-s-natural-galapagos-islands.)