The “Fantastic Giant Tortoise” – Believed To Be Extinct – Has Been Found Alive

Princeton University geneticist Stephen Gaughran has confirmed that "Fernanda" is connected to a tortoise that was removed from Fernandina Island more than a century ago and that both of them are genetically different from all other Galápagos tortoises.

A Galápagos species of tortoise that was previously believed to be extinct has been found to still be alive. The tortoise, named Fernanda after her native Fernandina Island, is the first of its kind to be found in more than a century.

The Fernandina Island Galápagos giant tortoise, sometimes known as the "wonderful gigantic tortoise," was only ever found as a single individual. The finding of a female tortoise on Fernandina Island in 2019 provided the opportunity to determine whether the species is still extant.

By sequencing the genomes of the living creature and the museum specimen and comparing them to the other 13 species of Galápagos giant tortoises, Stephen Gaughran from Princeton University proved that the two known Fernandina tortoises are members of the same species and genetically distinct from all other members. The survival of her species was proved by a recent paper he co-authored and published in the journal Communications Biology.

Peter Grant, Princeton's Class of 1877 Professor of Zoology, Emeritus, and an emeritus professor of ecology and evolutionary biology, has spent more than 40 years researching evolution in the Galápagos islands. "For many years it was thought that the original specimen collected in 1906 had been transplanted to the island, as it was the only one of its kind," he said. It now appears to be just a handful of people who were alive a century ago.

The first member of her species to be recognized in more than a century is Fernanda, named for the island where she lives, Fernandina. In order to prove that Fernanda and the museum specimen are members of the same species and genetically unique from all other Galápagos tortoises, Princeton geneticist Stephen Gaughran successfully retrieved DNA from a specimen that was obtained from the same island more than a century earlier. The Galápagos Conservancy, credit

When Fernanda was originally discovered, several ecologists questioned if she was actually a native phantasticus tortoise. She lacked the distinctive saddleback flare of the male historical example, but specialists speculated that she might have had malformed features due to her obviously limited development. Tortoises can be moved from one Galápagos island to another during hurricanes and other severe storms despite the fact that they cannot swim. According to historical sources, seamen have also carried the tortoises across islands.

According to Gaughran, a postdoctoral research researcher in ecology and evolutionary biology at Princeton, "like many people, my initial thought was that this was not a native tortoise of Fernandina Island."

Gaughran sequenced Fernanda's entire genome and compared it to the genome he was able to retrieve from the specimen recovered in 1906 in order to confirm Fernanda's species with certainty. Additionally, he examined samples from the other 13 species of Galápagos tortoises, including three members of each of the 12 extant species and one member of the extinct C. abingdonii, to compare those two genomes.

Following his arrival at the University in February 2021, Gaughran carried out the analyses. "We saw — honestly, to my surprise — that Fernanda was very similar to the one that they found on that island more than 100 years ago, and both of those were very different from all of the other islands' tortoises," he said.

He worked in Adalgisa Caccone's group at Yale University in 2019, who was the paper's senior author. The discovery of one living species, Caccone added, "gives hope and also raises fresh concerns, as there are still many riddles." Are there any other tortoises on Fernandina that can be re-captured to begin a breeding program? How did tortoises arrive in Fernandina, and how do they differ from the other huge Galápagos tortoises in terms of evolution? This demonstrates yet again how crucial it is to study historical documents in museums.

A component of Gaughran's postdoctoral work involves creating a technology that analyzes the DNA of historical museum specimens so that we can compare them to contemporary ones.

His instrument is adaptable enough to work on virtually any specimen from antiquity. He said that the software didn't care if it was a seal, tortoise, human, or Neanderthal. "For the most part, genetics is genetics. What kind of organism the DNA originates from matters in the interpretation.

Before "Fernanda" was discovered in 2019, the Fernandina Island Galápagos giant tortoise (Chelonoidis phantasticus, or "fantastic giant tortoise") was solely known from this lone specimen, taken in 1906. California Academy of Sciences, inc.

Gaughran collaborates with Bridgett vonHoldt and Andrea Graham at Princeton to solve the puzzles surrounding the development of pinnipeds (seals and walruses).

Graham, a professor of ecology and evolutionary biology, stated that Stephen uses the skillful and meticulous application of genomic and bioinformatic methods to solve conservation problems in species ranging from tortoises to pinnipeds.

VonHoldt, an associate professor of ecology and evolutionary biology, said of the man, "He has such a curiosity for discovering the secrets and codes nestled away in ancient remnants." "Stephen has been gathering samples that range in age from a few hundred to a few thousand years, and these really contain the keys to understanding the history of when and how genomes altered over time. I don't find it unexpected that he also oversaw the investigation of Fernanda's enigma, the wonderful ghost turtle that was rediscovered by molecular analysis. What an interesting find!

On Fernandina Island, an active volcano on the western end of the Galápagos Archipelago that is considered to be the biggest unspoiled island on Earth, there have been rumors of gigantic tortoises since 1906. However, there is little evidence to support these claims.

Explorer Rollo Beck gathered one specimen of C. phantasticus, sometimes known as "the amazing big tortoise," during a 1906 expedition. The "fantastic" nature alludes to the exceptional shape of the males' shells, which exhibit prominent saddlebacking at the front and extreme flaring along the outer edge. Galápagos tortoises are the only species that exhibit saddlebacking, and the phantasticus tortoise exhibits it more pronouncedly than the other species.

The survival of the Fernandina tortoise has been a matter of debate among biologists ever since it was first discovered in 1906. On the western slopes of the island, 18 scats attributed to tortoises were reported in 1964. Scats were recorded in the early 2000s, along with a potential visual observation from an aircraft, and another potential tortoise scat was spotted in 2014.                              

Because there are enormous lava fields that prevent access to the island's interior, the island has mostly gone unexplored.

Grant, alluding to his wife and study colleague Rosemary Grant, an emeritus senior research biologist at Princeton, noted that Ferdinanda was the highest of the Galápagos islands, geologically young, and primarily a big pile of jagged stones of brown lava. Lower elevations have clusters of flora that resemble islands in a sea of recently congealed lava. There is evidence that some of these contain relatives of Fernanda, who was discovered in one of them.

Fernanda is believed to be well over 50 years old, yet she is little, probably as a result of the sparse vegetation that hindered her growth. Fortunately, during other recent visits on the island, recent tracks and scat of at least 2 or 3 other tortoises were discovered.

One or more gigantic tortoises were transported westward from the South American peninsula two or three million years ago by a storm. Due to their inability to swim, the tortoises only interbred with those on their own islands, which led to rapid evolution — mimicking that of the more well-known Galápagos finches. Giant Galápagos tortoises currently come in 14 different species, all of which are descended from the same ancestor.

The Princeton-Yale team came to the conclusion that they are different enough, with thousands of distinctive genetic markers, to be separate species (although some experts disagree about whether these should be regarded species or subspecies).

The diversity of Galápagos tortoises exhibits a range of shell morphologies, from rounder, domed shells on the easternmost islands to the most spectacular saddlebacking on the westernmost island, Fernandina. While their saddlebacked counterparts reside in drier, lower elevation areas, the domed tortoises live in more humid, higher elevation ecosystems. All 14 are classified as vulnerable, endangered, critically endangered, or extinct on the IUCN Red List.

Because tortoises could survive on little food and water and could be kept alive on ships with little effort, European seamen who targeted them for food destroyed the tortoise populations. They provided the sailors with excellent fresh meat, but many of the species were severely overfarmed as a result, according to Gaughran. Additionally, due of their lengthy generation times, populations struggle to recover rapidly.

According to Grant, "the DNA analysis offers fascinating signs of a genetic mingling with individuals from another population." If future genetic research confirms that, it would be intriguing. Another interesting discovery is that the closest relatives are not on the nearby, very large island (Isabela), but rather on a different, distant island (Espaola), which is located on the opposite side of Isabela. The answer to how our forefathers got to Fernandina is still unknown.

At the Galápagos National Park Tortoise Center, a rescue and breeding facility, researchers are examining their options for preserving Fernanda's species.

Grant remarked, "The discovery tells us about uncommon species that might endure in remote locations for a long time." "This knowledge is crucial for conservation. To save a group from extinction, researchers are motivated to look even harder for its last few members.

The Galapagos giant tortoise Chelonoidis phantasticus is not extinct, according to a study published in Communications Biology on June 9th, 2022 by Evelyn L. Jensen, Stephen J. Gaughran, Nicole A. Fusco, Nikos Poulakakis, Washington Tapia, Christian Sevilla, Jeffreys Málaga, Carol Mariani, James P. Gibbs, and Adalgisa Caccone.

The study was supported by grants from the U.S. Fish and Wildlife Service, the California Academy of Sciences, the Yale Center for Research Computing, the Galápagos National Park Directorate, the Galápagos Conservancy, the Mohamed bin Zayed Species Conservation Fund, Re:Wild, Island Conservation, the Ecuadorian Ministry of the Environment, and the Mohamed bin Zayed Species Conservation Fund.

By PRINCETON UNIVERSITY