Mythical Yetis are Actually Bears, According to DNA Analysis

Walkabout Films via Flickr // CC BY-ND 2.0
Walkabout Films via Flickr // CC BY-ND 2.0

In 1959, the U.S. government advised hunters that they were permitted to kill a Yeti only in self-defense. The decree was prompted by findings from earlier expeditions—huge footprints, hides, and bones from a large, unidentified creature native to the Himalayas—which explorers thought could be from the mythical hominid that local Sherpas called the Yeti, or "wild man."

But now, researchers at the State University of New York in Buffalo and their colleagues have concluded that folklore about abominable snowmen in the Himalayas was just that. After testing evidence collected from the Tibetan Plateau and from museum collections, they found the biological root of the Yeti legends to be local bears.

In the new study, published in the Proceedings of the Royal Society B, researchers analyzed 24 hair, bone, tooth, skin, and scat samples. Nine of the samples were purported to be from Yetis, while the rest were gathered recently from the Tibetan brown bear, Himalayan brown bear, and Himalayan black bear. The team assembled complete mitochondrial genomes for the Himalayan brown bear and black bear for the first time, then analyzed and compared all of the samples. Of the nine allegedly from Yetis, eight were actually from Asian bears. One was from a dog.

While these particular findings suggest that the Yeti stories probably emerged from humans' encounters with bears, the study provides valuable genetic data that could shed light on how the bears evolved. The mitochondrial genomes—which are based on the genetic information passed down only through females—could reveal when the rare subspecies and more common bear species last shared a maternal ancestor, and how genetically dissimilar they are today, Science notes.

The genomic analysis showed that Tibetan brown bears share a close ancestry with North American and Eurasian brown bears. But the Himalayan brown bears branched off from their common ancestral tree about 650,000 years ago, when glaciers expanded over the Tibetan Plateau—which may have separated those bears from the larger gene pool. Understanding how the subspecies evolved could illuminate the environmental history of the region, said Charlotte Lindqvist, an associate professor of biological sciences at SUNY Buffalo and the study's lead scientist, in a statement. The genetic data may assist conservation of these vulnerable and endangered animals.

Lindqvist said that their technique could also be a useful tool for exploring the roots of folklore about large cryptids—as well as real beasts.

"Our findings strongly suggest that the biological underpinnings of the Yeti legend can be found in local bears," she said. "Our study demonstrates that genetics should be able to unravel other, similar mysteries."

A Simple Skin Swab Could Soon Identify People at Risk for Parkinson's

iStock.com/stevanovicigor
iStock.com/stevanovicigor

More than 200 years have passed since physician James Parkinson first identified the degenerative neurological disorder that bears his name. Over five million people worldwide suffer from Parkinson’s disease, a neurological condition characterized by muscle tremors and other symptoms. Diagnosis is based on those symptoms rather than blood tests, brain imaging, or any other laboratory evidence.

Now, science may be close to a simple and non-invasive method for diagnosing the disease based on a waxy substance called sebum, which people secrete through their skin. And it’s thanks to a woman with the unique ability to sniff out differences in the sebum of those with Parkinson's—years before a diagnosis can be made.

The Guardian describes how researchers at the University of Manchester partnered with a nurse named Joy Milne, a "super smeller" who can detect a unique odor emanating from Parkinson's patients that is unnoticeable to most people. Working with Tilo Kunath, a neurobiologist at Edinburgh University, Milne and the researchers pinpointed the strongest odor coming from the patients' upper backs, where sebum-emitting pores are concentrated.

For a new study in the journal ACS Central Science, the researchers analyzed skin swabs from 64 Parkinson's and non-Parkinson's subjects and found that three substances—eicosane, hippuric acid, and octadecanal—were present in higher concentrations in the Parkinson’s patients. One substance, perillic aldehyde, was lower. Milne confirmed that these swabs bore the distinct, musky odor associated with Parkinson’s patients.

Researchers also found no difference between patients who took drugs to control symptoms and those who did not, meaning that drug metabolites had no influence on the odor or compounds.

The next step will be to swab a a much larger cohort of Parkinson’s patients and healthy volunteers to see if the results are consistent and reliable. If these compounds are able to accurately identify Parkinson’s, researchers are optimistic that it could lead to earlier diagnosis and more effective interventions.

[h/t The Guardian]

World’s Oldest Stored Sperm Has Produced Some Healthy Baby Sheep

A stock photo of a lamb
A stock photo of a lamb
iStock.com/ananaline

It’s not every day that you stumble across a 50-year-old batch of frozen sheep sperm. So when Australian researchers rediscovered a wriggly little time capsule that had been left behind by an earlier researcher, they did the obvious: they tried to create some lambs. As Smithsonian reports, they pulled it off, too.

The semen, which came from several prize rams, had been frozen in 1968 by Dr. Steve Salamon, a sheep researcher from the University of Sydney. After bringing the sample out of storage, researchers thawed it out and conducted a few lab tests. They determined that its viability and DNA integrity were still intact, so they decided to put it to the ultimate test: Would it get a sheep pregnant? The sperm was artificially inseminated into 56 Merino ewes, and lo and behold, 34 of them became pregnant and gave birth to healthy lambs.

Of course, this experiment wasn’t just for fun. They wanted to test whether decades-old sperm—frozen in liquid nitrogen at -320°F—would still be viable for breeding purposes. Remarkably, the older sperm had a slightly higher pregnancy rate (61 percent) than sheep sperm that had been frozen for 12 months and used to impregnate ewes in a different experiment (in that case, the success rate was 59 percent).

“We believe this is the oldest viable stored semen of any species in the world and definitely the oldest sperm used to produce offspring,” researcher Dr. Jessica Rickard said in a statement.

Researchers say this experiment also lets them assess the genetic progress of selective breeding over the last five decades. “In that time, we’ve been trying to make better, more productive sheep [for the wool industry],” associate professor Simon de Graaf said. “This gives us a resource to benchmark and compare.”

[h/t Smithsonian]

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