A tortoise believed to be extinct has resurfaced after 150 years in the Galapagos Islands.
Researchers discovered in a genetic analysis that the DNA of the tortoise’s footprints, known as Chelonoidis elephantopus, exist in the genomes of its crossbred offspring. The mixed breed has recently been located on Isabela Island in the Galapagos.
In the study published in “Current Biology,” researchers including the study’s co-author and post doctoral fellow Ryan Garrick, went to Isabela Island in Northern Galapagos to take blood samples from over 1,600 tortoises of close relation called Chelonoidis becki. According to Live Science, the scientists compared the collected DNA to a DNA database of tortoise species both living and extinct.
The researchers were able to find the DNA traces of the Chelonoidis elephantopus in 84 of the tested tortoises. Since 30 of the species were found to be less than 15-years of age and tortoises live to be 100, scientists believe there is a possibility the full bred Chelonoidis elephantopus is still alive.
“This work also underscores the importance of museum collections in facilitating new discoveries," Garrick said to Discovery News.
“Here, we were able to extract DNA from tortoise bones that were collected many decades ago, and use this DNA to characterize the gene pool of purebred C. elephantopus.”
The tortoises were believed to be extinct because of the activities and exploitation of the species by navy ships, whalers, and buccaneers.
“Largely owing to the exploitation of tortoises for oil and as a source of food aboard ships, C. elephantopus from Floreana Island (its original home) was reported to be extinct soon after Charles Darwin's historic voyage to the Galapagos in 1835,” said Garrick to Discovery News.
“Indeed, it has been estimated that up to 200,000 tortoises were eliminated from the archipelago within only two centuries of intensive harvesting.”
Galapagos tortoises can weigh nearly 900 pounds and grow to be nearly six feet long. Researchers have not yet located a full breed of Chelonoidis elephantopus, but intend to return to the volcanic island to continue investigating.
This is the first time a species has been rediscovered by testing genetic footprints left in offspring, according to Discovery News.