Experts wish to bring an extinct subspecies of Galapagos tortoises back from the dead, after its last known member perished in June 2012.
Pinta island tortoises (scientifically known as Chelondoidis nigra abingdonii) were declared functionally extinct, after it was determined that Lonesome George, a tortoise first encountered by Hungarian naturalist József Vágvölgyi back in 1971, was actually the last surviving representative of this subspecies of Galapagos tortoises.
The rest of the population had probably died off as food sources became unusually sparse, after vegetation was severely depleted following the introduction of wild goats on Pinta island.
Another cause of their demise was likely related to overexploitation, since sailors relied on tortoises for sustenance during prolonged sea voyages.
The remaining endling nicknamed Lonesome George, after a film character invented by George Leslie Gobel, was taken to Charles Darwin Research Station, located on Santa Cruz Island.
Across the years, several attempts were made so that George would perpetuate at least part of its genetic makeup by mating with females from other subspecies of tortoises, but none of the eggs resulting from this breeding produced any offspring.
Eventually, after 41 years spent in captivity, Lonesome George died on June 24, 2012, probably as a result of old age, although scientists such as David Attenborough believe the reptile was just around 80 years old, while normally Galapagos tortoises can live for up to a century and a half.
Now researchers believe they have found a way to resurrect the Pinta island tortoise lineage, thanks to a related subspecies, found on Isabela Island, situated south of Lonesome George’s original habitat.
Apparently, in a study conducted in 2008, it was found that tortoises from Isabela Island actually have a large amount of George’s own DNA, which suggests that they may be genetically related, and that the Pinta Island legacy may not have been completely lost after all.
The Isabela habitat, marked by the presence of 5 active volcanoes, appears to have nurtured incredibly diverse wildlife, including the recently identified Galapagos pink land iguana, and a sizeable number of wild tortoises.
Therefore, the current plan that Ecuadorian and American scientists have devised is to attempt to take a few Isabela Island tortoises in captivity, and help them reproduce, so as to create offspring as genetically similar to Lonesome George as possible.
The hatchlings would afterwards be brought to Pinta Island, and it is hoped that as several generations pass, the descendants would eventually be almost identical to the original Pinta giant tortoises, as far genotype is concerned.
As explained by James Gibbs, who teaches Vertebrate Conservation Biology at the State University of New York College of Environmental Science and Forestry, while it won’t be able to create a “clone” for Lonesome George, the new tortoises will have around 95% of this endling’s DNA.
A similar idea involves Floreana Island tortoises (known as c.n. nigra), which were considered extinct by 1850, 15 years after Charles Darwin explored the region and only discovered carcasses belonging to this subspecies.
Apparently, the genotype of some Isabela island tortoises is 50% represented by indigenous DNA, while the other 50% is identical to that of Floreana or Pinta tortoises.
In fact, if the experiments succeed, this would not only mean that two extinct lines of wild animals would finally be revived in as few as 10 years, but also that Pinta island would be given a new lease of life.
The tortoises digest seeds and disperse them through their feces, thus assisting in plant germination, allowing the natural habitat to flourish.
Image Source: Flickr