May 14, 2007—Holding their breath for up to ten minutes, marine iguanas swim with sardines and sea lions in the Galápagos. Meanwhile, their cousins on land climb the volcanoes that spawned the islands (Ecuador map showing the Galápagos Islands).

The land lizards incubate their eggs in the warm volcanic ash, and the life of a young iguana only gets hotter. The young reptiles are often forced to take cover against predatory snakes and hawks.

Watch the saga of the iguanas, startling species that in the 1830s helped spark Charles Darwin's evolution revolution.