About 34 million years ago, the iguanas made the longest transoceanic journey of a terrestrial species, traveling about 8,000 kilometers from North America to Fiji, according to a new study.
Photo iguana: BBC capture
The authors of this study published Monday in the journal Proceedings of the National Academy of Sciences (PNAS) are of the opinion that the iguanas floated over 8,000 kilometers, worn by ocean currents on vegetation corks, reaching Fiji shortly after these islands appeared from the waters. “We can imagine a powerful cyclone that brought down trees and in a region with a large population of iguans and eggs of these reptiles, and then the trees were worn by the ocean currents.” supports the study coordinator, Simon Scarpetta, a professor of environmental sciences at the University of San Francisco, writes Agerpres.
The bright green lizards in Fiji are the only Iguani outside the western hemisphere, and scientists have not been able to explain so far how the iguans have reached these islands. Following a genetic analysis, the researchers concluded that the Fiji iguans are much closer to the western hemisphere igans than they were believed and they probably arrived in Fiji directly from the Western Coast, about 34 million years ago.
“The fact that they have reached Fiji directly from North America seems crazy,” said the co-author of this study, Jimmy McGuire, biology professor at University of California, Berkeley. “But the alternative variants, which involve the gradual colonization from adjacent terrestrial areas do not work for this period of time, because we know that the iguans have reached Fiji in the last 34 million years,” he added.
Previously, the biologists proposed the hypothesis that the Fiji – Brachylophus genus – would be drawn from a family of now missing iguanas that would have once populated the Pacific islands. Others have suggested that these reptiles would have floated over shorter distances from South America, via Antarctic or Australia before reaching the Pacific. However, these hypotheses were based on older genetic analyzes, which did not clearly establish how closely related Iguns with other iguanas.
The new study is based on DNA sequences in the whole genome, collected by scarpetta from over 200 specimens of iguane from museums worldwide. The study came to the conclusion that the genus Brachylophus in Fiji is very close to the genre of Diposaurus, of which the northern deserts populate the deserts. These desert iguanas are very well adapted to extreme temperatures and the absence of water and food, adaptations that have probably helped them on the sea.
“Igans and desert iguanas, in particular, are resistant to dehydration and lack of food, so I think that if there was a group of vertebrates or lizards who could survive an 8,000 kilometer trip on a vegetation bed, the ancestors of the desert are.“According to Scarpetta.
The researchers estimate that these genres of iguans broke up about 34 million years ago-about the time when the Fiji Islands were formed, which means that the Iguns were probably among the first “Colonists“You have these islands.
