Analysis of the saola genome indicates that the species could probably be saved through a captive breeding program with as few as 12 individuals.
Unfortunately, as everyone here already knows, even obtaining 12 saolas would be a small miracle, and it's not clear that their husbandry would be straightforward since it's not a species that was ever widely held in captivity...
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"Right now, the existence of live saolas can neither be proven nor disproven. The last evidence we have was from 2013, when one was captured on a camera trap. But given the remoteness of its habitat, it is extremely difficult to say for sure whether there are still a few out there. There are some signs and indications that still give us hope," says Nguyen Quoc Dung from the Forest Inventory and Planning Institute in Vietnam.
He is one of the authors of a new international study, in which researchers from Denmark, Vietnam and many other countries have mapped the saola's genome for the first time ever. Up until now, almost no genetic data on the saola have been generated. The study is published in the journal Cell.
By analyzing fragments from saola remains collected from hunters' households, the researchers generated complete genomes for 26 saolas. This has provided brand new insights into the history of the enigmatic bovine—and its future prospects.
"We were quite surprised to find that the saola is split into two populations with considerable genetic differences. The split happened between 5,000 and 20,000 years ago. That was completely unknown before, and there was also no way we could have known without genetic data. It is an important result because it affects how the genetic variation in the species is distributed," says lead author Genís Garcia Erill, a former Ph.D. student at the Department of Biology.
"This means that the genetic variation lost in each population complements the other. So, if you mix them, they could compensate for what the other is missing," says Garcia Erill.
And that could potentially be the solution to saving the saola from extinction. The researchers have calculated the probability of the species surviving under various conservation scenarios.
Their models show that the best survival chances occur if the two populations are mixed in a captive breeding program.
"If we can bring together at least a dozen saolas—ideally a mix from both populations—to form the foundation of a future population, our models show the species would have a decent chance of long-term survival. But it hinges on actually locating some individuals and starting a breeding program. That has worked before when species were on the brink of extinction," says Rasmus Heller, senior author of the study and Associate Professor from the Department of Biology at UCPH.
The genetic mapping opens up new possibilities for using various technologies to locate the last remaining saolas.
"Many researchers have unsuccessfully tried to find traces of saola through methods like environmental DNA in water and even in leeches, the blood suckers inhabiting the same habitat. These techniques all rely on detecting tiny DNA fragments, and now that we know the complete saola genome, we have a much larger toolkit for detecting those fragments," says Minh Duc Le, co-author on the study from Vietnam National University.
Saving the Asian unicorn—if it still exists: Saola genome mapped for first time