Iguanas have often been spotted rafting around the Caribbean on vegetation and, ages ago, evidently caught a 600-mile ride from Central America to colonize the Galapagos Islands. But for long-distance travel, the Fiji iguanas can't be touched. A new analysis conducted by biologists at the University of California, Berkeley, and the University of San Francisco (USF) suggests that sometime after about 34 million years ago, Fiji iguanas landed on the isolated group of South Pacific islands after voyaging 5,000 miles from the western coast of North America—the longest known transoceanic dispersal of any terrestrial vertebrate.
Overwater dispersal is the main way newly formed islands get populated by plants and animals, including humans, often leading to the evolution of new species and entirely new ecosystems. Understanding how these colonizations happen has fascinated scientists since the time of Charles Darwin, the originator of the theory of evolution by natural selection.
