July 3, 2014

Recent findings are sure to disappoint people who believe that the Yeti, or Abominable Snowman, stalks the Himalaya and that Bigfoot prowls the Pacific Northwest in the United States. In a study published last week, British scientists who examined samples of “Yeti hair” sent in by museums and cryptozoologists (people who study and search for legendary creatures) reported finding no Yeti yet. The study appeared online in the Proceedings of the Royal Society B.

The Yeti is a creature said to live on Mount Everest and other mountain ranges of Asia. According to legend, the Yeti is a hairy beast with a large, apelike body and a face that resembles that of a human being. (World Book illustration by Ted Lewis).

Many people are fascinated by the idea that a large primate like the Yeti—or its American cousin, Bigfoot, or Russian relative, Almasty—could survive in remote wilderness areas unexplored by modern science. Cryptozoologists have investigated the Yeti for decades. Sensational reports of Yeti sightings have been exposed as hoaxes and fakes in the past, which has led many skeptics to dismiss the creature as pure fantasy.

The study on Yeti hair was led by Bryan Sykes, a geneticist at Oxford University. In 2012, Sykes requested samples of hair from Yeti enthusiasts,  saying, “I’m challenging and inviting the cryptozoologists to come up with the evidence instead of complaining that science is rejecting what they have to say.” Scientists on the study ended up analyzing the DNA of more than 30 of the 57 “Yeti hair” samples submitted. The remaining samples were eliminating after the scientists found that they were not hair but such substances as fiberglass. The researchers discovered that most of the 30 analyzed hair samples came from such common animals as cows, horses, raccoons, deer, and coyotes. None of the samples came from a new primate species.

Two of the samples, however, were less straightforward: one was found in Ladakh—a region in Jammu and Kashmir, the northernmost state in India; and the other came from Bhutan to the east. The tests revealed that the hair was from a mammal, but it did not match samples from known primates. Surprisingly, the DNA from the two samples matched up almost exactly with DNA from the 40,000-year-old jawbone of a Norwegian polar bear. The researchers do not believe that the “Himalayan Yeti” actually represents an isolated population of polar bears. Instead, they theorize that the region is home to a hybrid bear species unknown to science that developed from matings between polar bears and brown bears somewhere in northern Asia during the last Ice Age, when the ranges of those bears overlapped.

Sykes admits that the study does not disprove the existence of the Yeti or other large primates unknown to scientists; it only means that the samples submitted for analysis did not come from such creatures. Enthusiasts need to keep looking for evidence that stands up to scientific scrutiny.

Additional World Book articles:

• Folklore
• Hillary, Sir Edmund Percival
• Journey to the Top of the World by Sir Edmund P. Hillary (a special report)

February 10, 2014

Polar bears live in some of the coldest climates on Earth. With enough food, polar bears can stay warm and cozy in temperatures that would quickly freeze a human to death. In a recent paper in the scientific journal Optics Express, researchers revealed a trick polar bears use to stay warm–their shiny white fur reflects waves of heat energy back into their bodies. Their research also helps solve the mystery of why polar bears are nearly invisible on infrared cameras.

For polar bears, white fur can be a blessing and a curse. Their pale color helps them blend into snow, making it easy for them to ambush prey. On the other hand, white fur—like a white t-shirt on a sunny day—scatters more of the sun’s heat than it absorbs. One might think polar bears would be better off with dark fur that absorbs more of the sun’s heat. (Scientists have disproven the idea that hollows within the strands of fur somehow channel solar radiation into the bear’s body.)

A baby polar bear rests on its mother in the Arctic snow. Polar bears give birth in late November or early December. (© Howard G. Buffett)

However, the sun is not the only object that radiates heat energy. All warm objects give off thermal radiation. This radiation is largely in the infrared range of the electromagnetic spectrum, beyond visible red light. Warm-blooded polar bears stand to lose a great deal of their body’s warmth via thermal radiation.

To learn how this bear-exiting radiation is affected by the bear’s fur, scientists used computer models. They looked at layers of furlike material of varying densities and transparencies. They found that polar bear fur acts like a “gray body”—somewhere between an all-absorbing “black body” and a heat-scattering “white body.” As thermal radiation leaves the polar bear’s body, some gets scattered through the fur, and some gets absorbed.  The fur works much like the reflective coating on the inside of insulated vacuum bottles that can keep coffee and soup warm for hours.

Additional World Book articles:

• Bear
• Wildlife conservation

October 18, 2013

Sensitive DNA tests on samples of hair recovered from the Himalaya indicate that the Yeti may actually exist, reported Bryan Sykes, a professor of genetics at the University of Oxford in the United Kingdom. Although this unexpected finding could potentially rank as one of the greatest zoological discoveries in history, fans of the legendary Yeti may be somewhat disappointed. The tests also show that the Yeti is not what people think it is.

The Yeti, which has also been called the Abominable Snowman, is said to be a creature with a human-like face and ape-like body that lives on Mount Everest and other mountains of the Himalaya range. According to local legend, the Yeti sometimes comes down from the mountains to attack villagers.

The legendary Yeti is a ape-like creature with a human-like face who lives in remote areas of the Himalaya. The real Yeti is probably something entirely different. (World Book illustration by Ted Lewis)

Many people are fascinated by the idea that a large primate like the Yeti–or its American cousin, Bigfoot–could survive in remote wilderness unexplored by modern science. Cryptozoologists, people who study and search for legendary creatures, have investigated the Yeti for decades. Sensational reports of Yeti sightings have been exposed as hoaxes and fakes in the past, and this has led many skeptics to dismiss the creature as pure fantasy.

However, reports of Yeti sightings continue to this day, and cryptozoology enthusiasts argue they demand explanation. Sykes made news in 2012 when he publicly asked wildlife scientists, museums, and Yeti believers to send him written descriptions and photos of any evidence they might have of the creature. If the descriptions looked promising, the researchers requested the physical samples and then tested the samples’ DNA to determine which species they came from.

Sykes and his team conducted sophisticated genetic tests on two samples of supposed Yeti hair discovered in the Himalaya: one found in Ladakh–a region in Jammu and Kashmir, the northernmost state in India; and another from Bhutan to the east. They compared the samples to the genetic codes of other animals from collections gathered over many years from all over the world. The tests revealed that the hair was from a mammal, but it did not match samples from known primates. Surprisingly, the DNA from the two samples matched up almost exactly with DNA from the 40,000-year-old jawbone of a Norwegian polar bear.

The researchers do not believe that the Himalayan Yeti actually represents an isolated population of polar bears. Instead, they theorize that the region is home to an unknown hybrid bear species that developed from matings between polar bears and brown bears somewhere in northern Asia during the last Ice Age, when the ranges of those bears overlapped. They point to antique Tibetan texts that describe the Yeti as a shy bear-like creature that is sometimes aggressive towards humans when encountered in its remote mountain domain. The scientists also point out that the animal may still survive in remote areas of the Himalaya, giving Yeti enthusiasts hope that the legendary creature may one day be found.

Additional World Book articles:

• Folklore
• Hillary, Sir Edmund Percival
• Journey to the Top of the World by Sir Edmund P. Hillary (a special report)