Analysis

In his book Bigfoot: The Yeti and Sasquatch in Myth and Reality, primatologist John Napier provides firsthand reports and analysis on the subject, and argues that amongst the evidence for the Yeti, "unlike the Sasquatch, there is little uniformity of pattern, and what uniformity there is incriminates the bear."
In 2003, Japanese mountaineer Makoto Nebuka published the results of his twelve year linguistic study postulating that the word "Yeti" is actually a corruption of the word "meti", a regional dialect term for "bear". As in other traditional cultures, the ethnic Tibetans fear and worship the bear as a supernatural being. Nebuka's claims were subject to almost immediate criticism, and was accused of linguistic carelessness. Dr Raj Kumar Pandey, who has researched both Yetis and mountain languages, said "it is not enough to blame tales of the mysterious beast of the Himalayas on words that rhyme but mean different things.
After reviewing eyewitness accounts and physical evidence, many cryptozoologists have concluded that Yeti reports are misidentification of mundane creatures. Even well-financed expeditions have turned up no positive evidence of its existence. One well publicized expedition to Bhutan reported that a hair sample had been obtained that, after DNA analysis by Prof. Bryan Sykes, could not be matched to any known animal. Analysis completed after the media release, however, clearly showed that the samples were from the Brown Bear (Ursus arctos) and the Asiatic Black Bear (Ursus thibetanus).
In 1997, South Tyrolean mountaineer Reinhold Messner claimed to have a face-to-face encounter with a Yeti. He has since written a book, My Quest for the Yeti, and claims to have actually killed one. According to Messner, the Yeti is actually the endangered Himalayan Brown Bear, Ursus arctos isabellinus, that can walk upright or on all fours.
Enthusiasts speculate that these reported creatures could be present-day specimens of the extinct giant ape Gigantopithecus, as the only evidence recovered from Gigantopithecus (other than teeth) are jawbone remains indicating a skull atop a vertical spinal column (as in hominines and other bipedal apes such as Oreopithecus). However, while the Yeti is generally described as bipedal, most scientists believe Gigantopithecus to be quadrupedal, and so massive that, unless it evolved specifically as a bipedal ape (like Oreopithecus and the hominids), walking upright would have been even more difficult for the now extinct primate than it is for its extant quadrupedal relative, the orangutan.