Sorry, yeti fans: On Monday, researchers published further confirmation that yetis are not, in fact, some unknown and ancient species of bear that's running around the Himalayas.
In case you missed it, in 2013, a group of researchers sequenced the genomes of hair attributed to mysterious creatures, such as the yeti, a.k.a the abominable snowman. Hair of the "yeti" turned out to have a fairly tantalizing genome, according to their findings: Their closest genetic match was to a a paleolithic polar bear. The researchers theorized that this might mean it was a living hybrid between this ancient bear and another species, one strange enough to inspire myths in the locals who spotted it.
If that sounds a little fishy to you, pat yourself on the back: It's fishy. It's so fishy that it's now been debunked twice.
In December, another group of researchers claimed that the genetic analysis was in error. The hair samples actually matched a rare sub-group of brown bear found in the Himalayas. This bear is still probably related to the yeti myth because of its rarity and size, but it's nothing so exotic as an undiscovered relic of bears long past. When that study came out, the authors of the yeti paper admitted that their results had probably been an error. But what really mattered was that the "yeti" was some kind of bear, they said.
"Importantly, for the thrust of the paper as a whole, the conclusion that these Himalayan 'yeti' samples were certainly not from a hitherto unknown primate is unaffected," they said in a statement. "We stressed in the original paper that the true identity of this intriguing animal needs to be refined, preferably by sequence data from fresh tissue samples derived from a living specimen where DNA degradation is no longer a concern."
Now a new paper, published Monday in the open-access journal ZooKeys, takes another step in solving this mysterious genetic flub. Just because the "yeti" isn't an unknown, mysterious primate doesn't mean we can pretend it's an unknown, mysterious bear.
Eliécer E. Gutiérrez, currently a postdoctoral fellow at the Smithsonian Institution, and Ronald H. Pine, affiliated with the Biodiversity Institute & Natural History Museum at the University of Kansas, found that the genetic overlap between brown bears and polar bears makes it easy to say that the sample came from either (or both) species.
"What motivated us was that the original paper basically claimed that an undiscovered bear species was lurking in the Himalayas, and when we read the paper we thought it was interesting that such a tiny piece of DNA was being used to make this claim so confidently," Gutiérrez said. It's true that new species -- even large ones, such as bears -- are discovered all the time. But when all you've got is a tuft of hair, the DNA evidence really has to back up your claims.
"The short answer is that there's a wide variation in that segment of DNA that they looked at," he said. "There's a large variation within brown bears that overlaps with the variation known for polar bears, so actually you can't even tell the two species apart based on that little species of DNA."
But because brown bears are common in that region, there's no reason to say it's a polar bear -- and there's nothing indicating that it's some unknown species. In other words, it's a really short fragment of DNA, and there's nothing in there that wouldn't fit right into the genome of a known species. No need to go dreaming up crazy ancient hybrids.