“Ancient Iguanas: How a 5,000-Mile Pacific Journey Unlocked the Secrets of Prehistoric Survival”
Iguanas have been observed “rafting” before, notably around the Caribbean. And researchers also suspect that rafting facilitated iguanas’ migration from Central America to the Galapagos Islands long ago. Scarpetta and his co-authors thus suggest that something similar happened in Fiji when North American iguanas rafted 5,000 miles to the island.
But 5,000 miles is a long way for a lizard to travel. So, Scarpetta and his team also had to argue why iguana rafting is more likely than any other possibility.
The Evidence Of Iguanas Rafting To Fiji
There are other theories about how iguanas got to Fiji. One is that the island’s iguanas are perhaps a member of an extinct group. Another suggests that the iguanas first crossed over land from the Americas to Asia or Australia and thus endured a much shorter crossing to Fiji.
Simon Scarpetta and Jim McGuireA map showing the various ways that iguanas may have made their way to Fiji millions of years ago.
As to the first point, Scarpetta and his team were able to determine that the Fiji iguanas are related to North American iguanas, not to an unknown species. To the second, the split in their genus some 30 million years ago came at a time when much of the Earth was cold and icy. This suggests that the heat-loving iguanas could not have survived a voyage through Asia or Australia at the time that they made their way to Fiji.
“[T]here [also] is no fossil evidence that iguanas ever inhabited anywhere in the Eastern Hemisphere besides Fiji and Tonga,” Scarpetta explained to All That’s Interesting. “On the other hand, there are several fossils of the desert iguana lineage and at least one other early iguana in North America.”
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