On September 15, 1835, the Galápagos Islands’ most illustrious visitor stepped off the H.M.S. Beagle and stepped foot on the islands. Though Darwin only explored Floreana, Isabela, Santiago, and San Cristóbal, he collected noteworthy observations of Galápagos mockingbirds, giant tortoises, and other flora and fauna.
It wasn’t until later that Darwin realized the implications of his Galápagos observations and the seeds of evolutionary theory took root. On the Origin of Species, published in 1859, brought the Galápagos Islands into the scientific limelight as Darwin countered the predominant theories with his observations of the island’s biodiversity.