Darwin Sets Sail
In December 1831, HMS Beagle set sail from England with a young 22-year-old Charles Darwin on board. The ship, which was under the command of Captain Robert Fitzroy, circumnavigated the globe on a 5-year surveying mission. Darwin, who had spent some time before the voyage studying geology, had been picked for the trip to be Fitzroy's unpaid companion.

It was on this trip that Darwin methodically collected a vast number of specimens and began to take note of the differences between species, particularly mockingbirds and tortoises on the Galapagos Islands. His studies resulted in his belief that these differences threw "some light on the origin of species" and his later theories of natural selection and evolution. This photo is of Lonesome George, thought to be the last surviving Pinto Island Tortoise, one of eleven species of Galapagos Tortoise studied by Darwin.