The HMS Beagle was a naval survey ship that left England in December 1831 to chart the coastal waters of Patagonia, Peru, and Chile—it carried onboard the not yet famous naturalist Charles Darwin. On the five-year voyage, Darwin’s job as unpaid companion to the captain on board the Beagle allowed him time to satisfy his interests in natural history. On its way to Asia, the ship spent time in the Galapagos Islands off the coast of Ecuador; Darwin’s observations of flora and fauna on those islands helped him to generate several ideas, especially his theory of natural selection. (For more about Darwin’s writings, see “Further Reading.”)