“Ancient Iguanas: How a 5,000-Mile Pacific Journey Unlocked the Secrets of Prehistoric Survival”
Though it may seem outlandish, the study’s authors believe that rafting is the only way that iguanas could have gotten to Fiji. And they say they have the evidence to back it up.
The Theory That Iguanas ‘Rafted’ From North America To Fiji
The study into Fiji’s iguanas, recently published in the Proceedings of the National Academy of Sciences, started with a question: Just how did Fiji’s four species of iguanas get to the island nation in the first place?
Fijian iguanas are the only iguanas that aren’t native to the Western Hemisphere, so the study authors’ first step was looking into their DNA. They found that the iguanas on Fiji, which belong to the genus Brachylophus, are closely related to the desert iguanas of the American Southwest and northwestern Mexico, which belong to the genus Dipsosaurus.
“Our analyses of genetic data, divergence dating, and biogeographic models found that Fijian iguanas are most closely related to North American desert iguanas,” lead author Simon Scarpetta, an assistant professor of Environmental Science at the University of San Francisco who began the study as a National Science Foundation postdoctoral fellowship at the University of California, Berkeley, explained to All That’s Interesting in an email.
What’s more, Scarpetta and his team found that “the divergence between the two groups is between 31 and 34 million years ago.” In other words, something happened then for Brachylophus to branch off from Dipsosaurus.
USGSA Central Fijian banded iguana, Brachylophus bulabula.
This was important, as the Fijian archipelago was formed some 34 million years ago by volcanic activity. Iguanas floating around in the ocean on loose vegetation would have had somewhere to land.
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