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November 24, 2012
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The sad death of conservation icon Lonesome George this past June in the Galápagos Islands marked the long-dreaded extinction of the Pinta Island tortoise (Chelonoidis nigra abingdoni). Or did it?
A team of researchers from Yale University now says the Pinta Island tortoise subspecies may actually still exist—not on Pinta Island but on nearby Isabella Island. The team collected and analyzed DNA from more than 1,600 giant tortoises on the northern tip of the island and found that 17 tortoises carried some of the same genes as the extinct Pinta Island subspecies.
Several giant tortoise subspecies live on Isabella Island. The region the Yale researchers worked in is home to the Volcán Wolf tortoise (C. n. becki), a subspecies named after a nearby volcano.
A Yale press release says the research on these hybrids has been published in Biological Conservation, but a search did not reveal their paper.
Some of the same Yale researchers contributed to a 2007 paper in Current Biology that first revealed that a single tortoise on Isabella Island contained mitochondrial DNA similar to those of the Pinta Island subspecies. Now, several years and many DNA tests later, more hybrids have been found. Even more importantly, five of the 17 hybrid tortoises were juveniles—less than 20 years old—which lead the researchers to suspect that at least one purebred PInta Island tortoise may be hiding somewhere on Isabella Island.
Isabella and Pinta islands are located about 60 kilometers apart, so the researchers don’t think that Pinta Island tortoises swam or floated to their new home. Instead, the animals were probably carried all or part of the way by the sailors that overran the Galápagos Islands in the nineteenth century, Fishermen and pirates frequently dined on giant tortoises and were the main cause for the decline of Lonesome George’s subspecies.
The Volcán Wolf region might hold even more genetic promise: A study published earlier this year in Current Biology revealed that 11 tortoises from the area carried the genes of yet another Galápagos tortoise species, C. elephantopus from Floreana Island, which was hunted into extinction in the 1850s.
The researchers and officials at Galápagos National Park say the hybrids could now be selectively bred to resurrect the Pinta Island subspecies—a process that could take 100 to 150 years.
Photo by A. Davey via Flickr. Used under Creative Commons license
About the Author: Twice a week, John Platt shines a light on endangered species from all over the globe, exploring not just why they are dying out but also what's being done to rescue them from oblivion. Follow on Twitter @johnrplatt.
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Awesome. Here’s to Galapagos tortoises!
Link to thisFor people who believe in evolution, they just can not seem to let evolution do it’s job!
Link to this@ jerryhamlittheunscientifictroll:
Link to thisActually, it’s entirely the fault of our species that these tortoises are in such bad shape. Read the entire article, you trollish buffoon. BTW, I’ve seen your previous unscientific rants, and I’m not impressed.
Was there any effort to freeze Georges’ semen in case a female was discovered?or to use in a close female subspecies?
Link to thisObviously the passing of Lonesome George (to answer the question in the headline) did not mark the end of his species but only perhaps the end of his subspecies. Now some people (Bird/tree/dinosaur/etc.geek) believe it is a big deal that any subspecies ever goes away. In the long history of biology subspecies come and go, it is the species that is the important unit. Only if all the subspecies of this tortoise are going away do we really have a problem.
Link to thisdicklipke, conservationists spent years trying to get George to mate with related subspecies. No luck. As I recall, even efforts to extract his sperm failed.
outsidethebox, I’ll disagree with you. Subspecies have their own roles to play and are just as important as species in the habitats in which they occur. Take something, anything, out of an ecosystem and you lose an important part of a system that evolved over thousands of years, often with disastrous effect. Beyond that, subspecies are often perfectly evolved for their particular habitats. Take tiger subspecies for example: you can’t take a Bengal tiger and put it in the habitat of the Siberian tiger and expect it (or any hybrid of the two subspecies) to thrive.
Link to this“”"Take tiger subspecies for example: you can’t take a Bengal tiger and put it in the habitat of the Siberian tiger and expect it (or any hybrid of the two subspecies) to thrive.”"”
In the right habitat, a hybrid would do fine. But a Bengal in an Amur tiger’s habitat? Seriously, a small (relatively), thin-coated, water-loving subspecies in the snowy taiga home of the giant Siberians? Recipe for disaster.
BTW, some species never develop subspecies because they’re already adaptable enough not to need any changes. Jaguars and cheetahs come to mind.
Link to thisoutsidethebox , I would think that the development of subspecies is the first step of evolution to form an entirely new species. Due to their longer life spans, tortoises would probably take quite a while to evolve to that point, but some species of fish and even some birds accomplish new species in a matter of decades.
Link to thisThere is some question as to whether the Galapagos tortoises on different islands/volcanoes are species/subspecies. The question is not as simple as whether they can be crossbred.
Link to thisAlso, there are subspecies in jaguar and cheetah. Remarkably specialised ones too. The Asian cheetah Acinonyx jubatus venaticus is markedly different to the African cheetah: http://en.wikipedia.org/wiki/Asiatic_Cheetah
Also the jaguar has a number of species both extinct and extant, including giant varieties such as Panthera onca augusta and P. o. mesembrina. http://en.wikipedia.org/wiki/Panthera_onca_augusta
@ barndad: Damn. Forgot Asian cheetah. I stand corrected.
Extant jaguar has no subspecies. Individuals travel so much that regional differences never get the chance to form. Yeah, I know about giant Florida jaguars from the Pleistocene (I’ve seen a *Glyptotherium floridianum* skull that had been bitten by one), but they are extinct. I think that the Eurpoean jaguar has been split into the species Panthera gombazongensis (and I’m sure that I misspelled that), BTW.
Link to thisHere’s the important part of the Wikipedia article:
Link to this“”"Recent studies have also failed to find evidence for well-defined subspecies, and are no longer recognized.[21] Larson (1997) studied the morphological variation in the jaguar and showed there is clinal north–south variation, but also the differentiation within the supposed subspecies is larger than that between them, and thus does not warrant subspecies subdivision.[22] A genetic study by Eizirik and coworkers in 2001 confirmed the absence of a clear geographical subspecies structure, although they found that major geographical barriers, such as the Amazon River, limited the exchange of genes between the different populations.[18] A subsequent, more-detailed study confirmed the predicted population structure within the Colombian jaguars.”"”
In a nutshell, jaguar subspecies are hard to determine and probably do not exist.
Link to thisFound a link for European Jaguar:
http://en.wikipedia.org/wiki/European_jaguar