The HMS Beagle was a naval survey ship that left England in December 1831 to chart the coastal waters of Patagonia, Peru, and Chile. On a voyage that would last five years, Darwin’s job as unpaid companion to the captain onboard the Beagle allowed him 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 there caused him to generate his theory of natural selection.