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."

No Venom, No Problem: This Spider Uses a Slingshot to Catch Prey

Courtesy of Sarah Han
Courtesy of Sarah Han

There are thousands of ways nature can kill, and spider species often come up with the most creative methods of execution. Hyptiotes cavatus, otherwise known as the triangle weaver spider, is one such example. Lacking venom, the spider manages to weaponize its silk, using it to hurl itself forward like a terrifying slingshot to trap its prey.

This unusual method was studied up close for a recent paper published in the Proceedings of the National Academy of Sciences by researchers at the University of Akron in Ohio. They say it's the only known instance of an animal using an external device—its web—for power amplification.

Hyptiotes cavatus's technique is simple. After constructing a web, the spider takes one of the main strands and breaks it in half, pulling it taut by moving backwards. Then, it anchors itself to a spot with more webbing in the rear. When the spider releases that webbing, it surges forward, propelled by the sudden release of stored energy. In the slingshot analogy, the webbing is the strap and the spider is the projectile.

This jerking motion causes the web to oscillate, tangling the spider's prey further in silk. The spider can repeat this until the web has completely immobilized its prey, a low-risk entrapment that doesn’t require the spider to get too close and risk injury from larger victims.

The triangle weaver spider doesn’t have venom, and it needs to be proactive in attacking and stifling prey. Once a potential meal lands in its web, it’s able to clear distances much more quickly using this slingshot technique than if it crawled over. In the lab, scientists clocked the spider’s acceleration at 2535 feet per second squared.

Spiders are notoriously nimble and devious. Cebrennus rechenbergi, or the flic-flac spider, can do cartwheels to spin out of danger; Myrmarachne resemble ants and even wiggle their front legs like ant antennae. It helps them avoid predators, but if they see a meal, they’ll drop the act and pounce. With H. cavatus, it now appears they’re learning to use tools, too.

[h/t Live Science]

Bad News: The Best Time of the Day to Drink Coffee Isn’t as Soon as You Wake Up

iStock.com/ThomasVogel
iStock.com/ThomasVogel

If you depend on coffee to help get you through the day, you can rest assured that you’re not the world's only caffeine fiend. Far from it. According to a 2018 survey, 64 percent of Americans said they had consumed coffee the previous day—the highest percentage seen since 2012.

While we’re collectively grinding more beans, brewing more pots, and patronizing our local coffee shops with increased frequency, we might not be maximizing the health and energy-boosting benefits of our daily cup of joe. According to Inc., an analysis of 127 scientific studies highlighted the many benefits of drinking coffee, from a longer average life span to a reduced risk for cancer, heart disease, type 2 diabetes, and Parkinson’s disease.

Sounds great, right? The only problem is that the benefits of coffee might be diminished depending on the time of day that you drink it. Essentially, science tells us that it’s best to drink coffee when your body’s cortisol levels are low. That’s because both caffeine and cortisol cause a stress response in your body, and too much stress is bad for your health for obvious reasons. In addition, it might end up making you more tired in the long run.

Cortisol, a stress hormone, is released in accordance with your circadian rhythms. This varies from person to person, but in general, someone who wakes up at 6:30 a.m. would see their cortisol levels peak in different windows, including 8 to 9 a.m., noon to 1 p.m., and 5:30 to 6:30 p.m. Someone who rises at 10 a.m. would experience cortisol spikes roughly three hours later, and ultra-early risers can expect to push this schedule three hours forward.

However, these cortisol levels start to rise as soon as you start moving in the morning, so it isn’t an ideal time to drink coffee. Neither is the afternoon, because doing so could make it more difficult to fall asleep at night. This means that people who wake up at 6:30 a.m. should drink coffee after that first cortisol window closes—roughly between 9:30 a.m. and 11:30 a.m.—if they want to benefit for a little caffeine jolt.

To put it simply: "I would say that mid-morning or early afternoon is probably the best time," certified dietitian-nutritionist Lisa Lisiewski told CNBC. "That's when your cortisol levels are at their lowest and you actually benefit from the stimulant itself."

[h/t Inc.]

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