Overview

• Iguanas floated 5,000 miles from North America to Fiji approximately 34 million years ago, making it the longest-known migration of any terrestrial vertebrate.
• Genetic analysis links Fijian iguanas (Brachylophus genus) closely to North American desert iguanas (Dipsosaurus genus), supporting a direct migration route.
• The journey likely occurred shortly after the formation of Fiji's volcanic islands, aligning with the divergence timeline of the iguana species.
• Traits such as resistance to starvation and dehydration likely enabled the iguanas to survive the months-long journey on vegetation mats uprooted by extreme weather events.
• The study challenges earlier theories of migration via Antarctica or Australia and underscores the evolutionary importance of long-distance dispersal in shaping species distribution.