How to decide which extinct species we should resurrect

De-extinction could soon become reality – and the Int’l Union for the Conservation of Nature is already making plans to encourage proper use of the technology

Imagine taking a cruise to Mauritius to be greeted by waddling dodos. Maybe you would prefer a Siberian safari and a chance to catch a glimpse of a woolly mammoth, or a voyage to either Australia – for the Tasmanian tiger tour – or New Zealand, to look for Giant Moas.

There is just one small problem with these eco-tourism options: all of these animals are extinct. But imagine if they were not. Perhaps one day this possibility will be realised. Scientists are developing technologies to bring extinct species back to life – a process termed "de-extinction".
The mention of de-extinction naturally conjures images of the most charismatic of extinct species. But what about the Saint Helena olive tree? Or Rabbs' fringe-limbed tree frog? The last member of this amphibious species, named Toughie, died in September 2016 in the Atlanta Botanical Garden in Georgia, US. How do you choose which species to bring back?
We could ask the experts – except that there none, yet. Technology has not advanced far enough to make the resurrection of extinct species a genuine possibility. For the moment, conversations around de-extinction largely involve crystal-ball forecasting. Still, the theoretical possibility is being taken seriously.
The International Union for the Conservation of Nature is responsible for assigning the conservation status of each species. The IUCN is confident that technology will inevitably progress to the point that de-extinction becomes a viable option. Confident enough, in fact, that they gathered a group of conservation experts to draft an unusual document – published in May 2016 – with guidelines for managing species that are currently extinct.
Axel Moehrenschlager, director of conservation and science at the Calgary Zoo in Canada, and Phil Seddon from the University of Otago in New Zealand helped draft these new IUCN guidelines. They are both experts in re-introduction – bringing (living) species back to landscapes in which they once lived. After all, de-extinction and re-introduction are conceptually similar.
Under what conditions should it be done and what would it mean for conservation? 
The goal, they stress, should not be to resurrect species simply so that a single flashy individual can be put on show in a zoo.
Instead, de-extinction should be viewed in the same way as existing re-introduction programmes: the aim would be to generate a genetically-diverse, viable population, living in a robust habitat.
A 2013 TEDx conference on de-extinction stimulated people's imagination and much debate. Until that point, research had primarily tried to figure out whether it could be done.
"But we (the IUCN) asked under what conditions should it be done and what would it mean for conservation?" says Moehrenschlager.
"We've got a window of opportunity now to get people thinking about the complexities of what would be involved," says Seddon.
The IUCN does not endorse de-extinction. They drafted their 2016 guidelines on the subject pro-actively so that if the process eventually becomes a tool for conservationists, there are protocols in place. Since re-introductions involve uncertainty even with familiar species, a little forethought would not be amiss when introducing a species that maybe has not existed for tens of thousands of years.
We've got a window of opportunity now to get people thinking 
"We know from re-introducing existing species in areas where they've been missing for a while that you can have all sorts of unintended consequences," Seddon says.
Each component species in an ecosystem has a role. For example, grazing animals keep vegetation in check, while top predators keep prey population numbers manageable.
"We're still grappling with the idea of func tionality in ecosystems but we do understand that some species are less redundant than others," says Seddon. "De-extinction could be the art of trying to bring something back that would fill in the gap or serve the same purpose in that ecosystem." The idea is similar to ecological replacement programmes. Moehrenschlager describes re-populating islands in the Seychelles and the Caribbean with tortoises. The replacement tortoises perform crucial browsing functions that extinct tortoise species used to do.
Replacement and re-introduction programmes around the world generally follow IUCN guidelines to decide which species to work with and where they should go. Moehrenschlager and Seddon wondered if they could use a similar template to theoretically pick a viable candidate species to resurrect.
In 2014 they created a ten-question screening test for potential de-extinction candidates. The questions range from the causes of extinction to habitat needs and the impact and potential risks of re-introduction. The IUCN declared the Yangtze River dolphin functionally extinct in 2006 
For instance, do we know why the species went extinct and can we address current or future triggers of extinction? If we do not know why it died out in the first place, then protecting it from extinction after it has been resurrected would be almost impossible.
Is there appropriate habitat for the species and will it still be available in the future? To answer this, conservationists need to understand the climate, physical space, and food requirements of the candidate species.
Finally, can the impacts and potential risks of resurrection be predicted, mitigated, and controlled? Re-introduced species could outcompete the current inhabitants of the ecosystem or spread diseases that infect livestock or people. They could interfere with agriculture or people's livelihoods. If any of these scenarios come to fruition, how easy would it be to fix the situation?
"If you fail the test, you're out," says Moehrenschlager, "but if you pass, you're only good enough to go to the next stage of assessment."
The IUCN declared the Yangtze River dolphin functionally extinct in 2006 (although there was an unconfirmed sighting of one in October 2016). It lived in one of the most densely-populated areas on the planet and suffered from a combination of pollution, hunting and habitat loss. Some individuals died after becoming tangled in fishing nets.
Would the Xerces butterfly capture the public's attention if it became the first species chosen for de-extinction? 
All the original threats to its survival remain. Industrial waste continues to be pumped into the river, which will only cause further degradation of the habitat. As with any species, efforts to bring the dolphin back are irrelevant if there is nowhere to put them.     —BBC

How to decide which extinct species we should resurrect

De-extinction could soon become reality – and the Intl Union for the Conservation of Nature is already making plans to encourage proper use of the technology

Imagine taking a cruise to Mauritius to be greeted by waddling dodos. Maybe you would prefer a Siberian safari and a chance to catch a glimpse of a woolly mammoth, or a voyage to either Australia for the Tasmanian tiger tour or New Zealand, to look for Giant Moas. There is just one small problem with these eco-tourism options: all of these animals are extinct. But imagine if they were not. Perhaps one day this possibility will be realised. Scientists are developing technologies to bring extinct species back to life a process termed de-extinction. The mention of de-extinction naturally conjures images of the most charismatic of extinct species. But what about the Saint Helena olive tree? Or Rabbs fringe-limbed tree frog? The last member of this amphibious species, named Toughie, died in September 2016 in the Atlanta Botanical Garden in Georgia, US. How do you choose which species to bring back? We could ask the experts except that there none, yet. Technology has not advanced far enough to make the resurrection of extinct species a genuine possibility. For the moment, conversations around de-extinction largely involve crystal-ball forecasting. Still, the theoretical possibility is being taken seriously. The International Union for the Conservation of Nature is responsible for assigning the conservation status of each species. The IUCN is confident that technology will inevitably progress to the point that de-extinction becomes a viable option. Confident enough, in fact, that they gathered a group of conservation experts to draft an unusual document published in May 2016 with guidelines for managing species that are currently extinct. Axel Moehrenschlager, director of conservation and science at the Calgary Zoo in Canada, and Phil Seddon from the University of Otago in New Zealand helped draft these new IUCN guidelines. They are both experts in re-introduction bringing (living) species back to landscapes in which they once lived. After all, de-extinction and re-introduction are conceptually similar. Under what conditions should it be done and what would it mean for conservation? The goal, they stress, should not be to resurrect species simply so that a single flashy individual can be put on show in a zoo. Instead, de-extinction should be viewed in the same way as existing re-introduction programmes: the aim would be to generate a genetically-diverse, viable population, living in a robust habitat. A 2013 TEDx conference on de-extinction stimulated peoples imagination and much debate. Until that point, research had primarily tried to figure out whether it could be done. But we (the IUCN) asked under what conditions should it be done and what would it mean for conservation? says Moehrenschlager. Weve got a window of opportunity now to get people thinking about the complexities of what would be involved, says Seddon. The IUCN does not endorse de-extinction. They drafted their 2016 guidelines on the subject pro-actively so that if the process eventually becomes a tool for conservationists, there are protocols in place. Since re-introductions involve uncertainty even with familiar species, a little forethought would not be amiss when introducing a species that maybe has not existed for tens of thousands of years. Weve got a window of opportunity now to get people thinking We know from re-introducing existing species in areas where theyve been missing for a while that you can have all sorts of unintended consequences, Seddon says. Each component species in an ecosystem has a role. For example, grazing animals keep vegetation in check, while top predators keep prey population numbers manageable. Were still grappling with the idea of func tionality in ecosystems but we do understand that some species are less redundant than others, says Seddon. De-extinction could be the art of trying to bring something back that would fill in the gap or serve the same purpose in that ecosystem. The idea is similar to ecological replacement programmes. Moehrenschlager describes re-populating islands in the Seychelles and the Caribbean with tortoises. The replacement tortoises perform crucial browsing functions that extinct tortoise species used to do. Replacement and re-introduction programmes around the world generally follow IUCN guidelines to decide which species to work with and where they should go. Moehrenschlager and Seddon wondered if they could use a similar template to theoretically pick a viable candidate species to resurrect. In 2014 they created a ten-question screening test for potential de-extinction candidates. The questions range from the causes of extinction to habitat needs and the impact and potential risks of re-introduction. The IUCN declared the Yangtze River dolphin functionally extinct in 2006 For instance, do we know why the species went extinct and can we address current or future triggers of extinction? If we do not know why it died out in the first place, then protecting it from extinction after it has been resurrected would be almost impossible. Is there appropriate habitat for the species and will it still be available in the future? To answer this, conservationists need to understand the climate, physical space, and food requirements of the candidate species. Finally, can the impacts and potential risks of resurrection be predicted, mitigated, and controlled? Re-introduced species could outcompete the current inhabitants of the ecosystem or spread diseases that infect livestock or people. They could interfere with agriculture or peoples livelihoods. If any of these scenarios come to fruition, how easy would it be to fix the situation? If you fail the test, youre out, says Moehrenschlager, but if you pass, youre only good enough to go to the next stage of assessment. The IUCN declared the Yangtze River dolphin functionally extinct in 2006 (although there was an unconfirmed sighting of one in October 2016). It lived in one of the most densely-populated areas on the planet and suffered from a combination of pollution, hunting and habitat loss. Some individuals died after becoming tangled in fishing nets. Would the Xerces butterfly capture the publics attention if it became the first species chosen for de-extinction? All the original threats to its survival remain. Industrial waste continues to be pumped into the river, which will only cause further degradation of the habitat. As with any species, efforts to bring the dolphin back are irrelevant if there is nowhere to put them. BBC