In 1835, 22-year-old Charles Darwin boarded the HMS Beagle as the ship's naturalist. The Beagle was embarking upon a charting voyage around South America. On the return trip, the Beagle stayed in the Galapagos for 5 weeks. Darwin spent 19 days on the islands of San Cristobal, Isabela, Floreana and Santiago collecting geological and biological specimens and taking detailed notes.
As the Beagle sailed home for England, Darwin looked over and noticed something: San Cristobal and Santiago, Isabela and Floreana contained three different species of mockingbird, even though the islands were located close together and had similar environments. The English Vice-Governor, Nicolas Lawson, had also noted that the tortoises on different islands had slight variations in their shells.
Darwin showed his haphazardly-labeled collection of specimens to ornithologist John Gould, who noted that some of the birds Darwin had collected looked to be ground finches, with 12 new species within that group. Darwin realized that the specimens he had collected suggested that the animals had grown different after living on different islands and being exposed to different environments. Darwin also took his collection to botanist Joseph Dalton Hooker, who found that the plants were closely related, but not identical, to the flora of South America. He found that of the 217 species collected, 109 were unique to the Galapagos Islands and 85 were unique to a single island.
These findings led to the publishing of "On the Origin of the Species" in 1859.In the book, Darwin presented his findings of unique island species that were interrelated yet slightly different on each island and were missing some groups of species. He explained that this occurred through "natural selection", in which a species that varies on a particular trait that makes them more likely to survive, then more of the species with that particular trait are going to exist in the future. His argument opposed the overwhelmingly Creationist views of the time, which assumed that a higher being had created all life on Earth.
Evolutionary Biologists like to study islands because the species that inhabit the island can more clearly illustrate evolutionary processes. The Galapagos Islands are unique because of their sunny equatorial position combined with their location among cool ocean currents. This causes them to have a mix tropical and temperate environments, which allows unusual plants and animals to live there. The Galapagos Islands have no native plant or animal life -- all species arrived to the islands by air or sea.
Charles Darwin's findings spurred more generations of scientific researchers in the Galapagos Islands. Although Darwin killed his specimens and ate Galapagos tortoises during his visit to the islands, today researchers are much more aware of the need for conservation. The Charles Darwin Foundation for the Galapagos Island is an international non-profit organization founded in 1959 that established a research center in Santa Cruz in 1964. The foundation continues the researcher's natural and biological studies with a mind for conservation and preservation of the islands.
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