Galápagos Islands, Ecuador
Where Darwin Found Natural Selection
In Charles Darwin’s day, the Galápagos Islands were perhaps the best place in the world to observe evidence of evolution by natural selection. They still are.
The 19 islands are the tips of volcanoes that began emerging from the ocean some five million years ago, steaming with fresh lava and devoid of life. The plants and animals that dwell there today are descended from castaways that arrived by sea or air. Finches and mockingbirds were blown off course by storms; iguanas floated on rafts of debris; and the tree-like scalesia plants are the overgrown progeny of sunflowers that made landfall via airborne seeds. It’s easy to study the diversity of species here in part because there aren’t all that many species to see.
The islands—separated from one another by distance, deep water and strong tides—isolated the newcomers, preventing many of the plants and animals from breeding with others of their kind that may have colonized other shores. With no place else to go, the Galápagos’ denizens adapted to conditions unique to their new homes.
