How did iguanas end up in Fiji? By raft

Most iguanas are indigenous to the Americas. So how did the Fijian species end up on the island, nearly 5000 miles away in the South Pacific? According to a new study in the journal PNAS, it was probably via raft ... that is, on clump of floating trees. And this rafting hypothesis isn't entirely unprecedented. After hurricanes Luis and Marilyn hit the Caribbean in the 1990s, researchers found that a group of iguanas had floated over 180 miles away from Guadeloupe to the territory of Anguilla. Want to hear more about iguanas? Or rafts? Or evolutionary biology? Email us at shortwave@npr.org.Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.

Apr 1, 2025 - 08:02

A native green iguana on Fiji. For years, biologists puzzled over how these iguanas had ended up in the South Pacific, so far from other iguana species. A new study sheds light on their evolution.

Most iguanas are indigenous to the Americas. So how did the Fijian species end up on the island, nearly 5000 miles away in the South Pacific? According to a new study in the journal PNAS, it was probably via raft ... that is, on clump of floating trees.

And this rafting hypothesis isn't entirely unprecedented. After hurricanes Luis and Marilyn hit the Caribbean in the 1990s, researchers found that a group of iguanas had floated over 180 miles away from Guadeloupe to the territory of Anguilla.

Want to hear more about iguanas? Or rafts? Or evolutionary biology? Email us at shortwave@npr.org.

Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.

(Image credit: tobiasjo)