How did iguanas get to Fiji? Chances are, they floated nearly 5,000 miles on vegetation rafts

Yahoo! News - Mar 21st, 2025
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A new study reveals that the ancestors of modern iguanas undertook a remarkable 5,000-mile journey across the Pacific Ocean from North America to Fiji around 34 million years ago. These iguanas likely traveled on floating vegetation, solving a long-standing mystery about how they reached such remote islands. The research, led by Dr. Simon Scarpetta, provides genetic evidence supporting the theory of overwater rafting, which challenges previous hypotheses suggesting overland migration from Asia or Australia. The findings, published in the Proceedings of the National Academy of Sciences, offer new insights into the biogeographic origins of Fijian iguanas and the role of major weather events in species dispersal.

The study's implications extend beyond iguanas, suggesting that overwater dispersal could have significantly contributed to species diversity on islands worldwide. By analyzing the genes of 14 living iguana species, researchers linked Fijian iguanas to their closest relatives, the Dipsosaurus of North America, estimating their divergence between 34 and 30 million years ago. This timeline aligns with the volcanic formation of the Fijian archipelago. The research highlights iguanas' unique adaptations for long-distance travel, such as their ability to endure extreme conditions and limited food resources, providing a model for understanding how other species might survive similar journeys.

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RATING

8.6
Fair Story
Consider it well-founded

The article is a well-researched and accurate presentation of a fascinating scientific discovery about the migration of iguanas to Fiji. It is supported by credible sources and expert opinions, which enhance its reliability. The narrative is clear and engaging, making complex scientific concepts accessible to a general audience. The article effectively balances scientific evidence with expert perspectives, although it could benefit from a more detailed exploration of alternative theories.

While the article primarily appeals to readers interested in science and natural history, it has broader public interest due to its intriguing narrative. Its impact is mainly within the scientific community, contributing to ongoing discussions about species dispersal and island colonization. Overall, the article is a strong example of science journalism, combining accuracy, clarity, and engagement to convey a compelling story.

RATING DETAILS

9
Accuracy

The article is largely accurate and well-supported by scientific studies and expert opinions. The main claim that iguanas traveled nearly 5,000 miles from North America to Fiji around 34 million years ago is backed by genetic evidence and aligns with known geological timelines. The article correctly references the study published in the Proceedings of the National Academy of Sciences, providing a credible source for its claims.

The explanation of iguanas' survival capabilities during such a journey is detailed and supported by examples, such as the 1995 incident where iguanas appeared on Caribbean beaches after a hurricane. This example illustrates the plausibility of the rafting hypothesis. The timeline of divergence between Fijian and North American iguanas is also well-documented, with genetic data supporting the claim.

However, the article could benefit from more detailed exploration of alternative theories, such as overland migration, to provide a comprehensive view. Overall, the story accurately conveys the scientific findings and presents a credible narrative backed by evidence.

8
Balance

The article presents a balanced view of the scientific debate regarding the origins of Fijian iguanas. It acknowledges multiple theories, including overwater rafting and overland migration, and provides evidence supporting the rafting hypothesis. The inclusion of expert opinions, such as those from Dr. Simon Scarpetta and Dr. Jimmy McGuire, adds depth to the discussion.

While the article focuses primarily on the rafting theory, it does mention previous theories, such as migration from Asia or Australia, and the potential overland journey via Antarctica. However, these alternatives are not explored in as much detail, which could lead to a slight imbalance in the presentation of perspectives.

Overall, the article effectively balances the scientific evidence with expert opinions, providing a well-rounded view of the topic. Including more detailed counterarguments could enhance the balance further.

9
Clarity

The article is well-written and clear, with a logical structure that guides the reader through the complex scientific topic. The language used is accessible and avoids overly technical jargon, making the content understandable to a general audience.

The narrative is structured in a way that presents the main claims first, followed by supporting evidence and expert opinions. This helps maintain reader engagement and ensures that the information is presented in a coherent manner.

Overall, the article demonstrates excellent clarity, with a well-organized structure and clear language that facilitates comprehension. The use of examples and expert quotes further enhances the clarity of the content.

9
Source quality

The article relies on high-quality sources, including a study published in the Proceedings of the National Academy of Sciences, a reputable scientific journal. This lends significant credibility to the claims made in the story. The article also cites experts in the field, such as Dr. Simon Scarpetta and Dr. Jimmy McGuire, who provide authoritative perspectives on the topic.

The use of genetic evidence and historical examples, like the 1995 Caribbean iguana incident, further strengthens the source quality. These sources are well-integrated into the narrative, providing a robust foundation for the claims made.

Overall, the article demonstrates strong source quality, with credible and authoritative references supporting the story's main points. The reliance on peer-reviewed research and expert testimony enhances the article's reliability.

8
Transparency

The article is transparent in its presentation of the scientific study and the evidence supporting the iguanas' journey to Fiji. It clearly attributes findings to the study published in the Proceedings of the National Academy of Sciences and provides context for the research conducted by Dr. Simon Scarpetta and his team.

The article explains the methodology used in the study, such as genetic analysis, and discusses the implications of the findings. However, it could benefit from more detailed explanations of the limitations of the study or the uncertainties involved in the genetic analysis, as noted by Dr. Shane Campbell-Staton.

Overall, the article maintains a high level of transparency, clearly attributing sources and explaining the basis for its claims. Including more information on the study's limitations would further enhance transparency.

Sources

  1. https://www.livescience.com/animals/lizards/iguanas-sailed-one-fifth-of-the-way-around-the-world-on-rafts-34-million-years-ago
  2. https://reptilesmagazine.com/iguanas-from-fiji-came-from-north-america-34-million-years-ago-study-says/
  3. https://indianexpress.com/article/explained/explained-sci-tech/voyage-of-the-iguanas-how-they-travelled-from-americas-to-fiji-9897398/
  4. https://www.sciencenews.org/article/iguanas-crossed-pacific-ocean-fiji
  5. https://www.universityofcalifornia.edu/news/iguanas-floated-fiji-millions-years-ago-unprecedented-raft-journey-scientists-say