Last October I reported on a tentative claim by geneticist Bryan Sykes of the Oxford-Lausanne Collateral Hominid Project that he might have solved the Yeti question, only the Yeti is a descendant of a Paleolithic bear known from a single jawbone from northern Norway. This bear is believed to be ancestral to both the polar bear and the brown bear. His claim was based on a comparison of mitochondrial DNA (mtDNA) from samples of hair claimed to have come from Yetis with those of known species held on the GenBank database, an international database of genetic information.
mtDNA is inherited in mammals from the female line only and, because it doesn't recombine during sexual reproduction, tends to be stable over time, mutating at a more or less constant rate. It thus makes an excellent means of tracing female line populations and evolutionary relationships. The biological significance of this find was not so much that it might have solved the Yeti question but that it might have revealed a living population of this Ice-Age bear in the Himalayas, where it might have taken refuge as the ice retreated.
Now Bryan Sykes has reported on a much more extensive investigation of mtDNA from hair samples of 'Yeti', 'Bigfoot', and other so-called anomalous primates from various places, including museum specimens.
Abstract*
In the first ever systematic genetic survey, we have used rigorous decontamination followed by mitochondrial 12S RNA sequencing to identify the species origin of 30 hair samples attributed to anomalous primates. Two Himalayan samples, one from Ladakh, India, the other from Bhutan, had their closest genetic affinity with a Palaeolithic polar bear, Ursus maritimus. Otherwise the hairs were from a range of known extant mammals.
Bryan C. Sykes, Rhettman A. Mullis, Christophe Hagenmuller, Terry W. Melton and Michel Sartori;
Genetic analysis of hair samples attributed to yeti, bigfoot and other anomalous primates 2 July 2014
Proc. R. Soc. B 22 August 2014 vol. 281 no. 1789 20140161 doi: 10.1098/rspb.2014.0161
The results are not entirely surprising and it's not looking good for the existence of any anomalous primates, least of all Bigfoot.
Ref. no. | Location | Attribution | GenBank Sequence Match | Common Name |
---|---|---|---|---|
25025 | Ladakh, India | yeti | U. maritimus | polar bear |
25191 | Bhutan | yeti/migyhur | U. maritimus | polar bear |
25092 | Nepal | yeti | Capricornis sumatraensis | serow |
25027 | Russia | almasty | U. arctos | brown bear |
25039 | Russia | almasty | Equus caballus | horse |
25040 | Russia | almasty | Bos taurus | cow |
25041 | Russia | almasty | Equus caballus | horse |
25073 | Russia | almasty | Equus caballus | horse |
25074 | Russia | almasty | U. americanus | American black bear |
25075 | Russia | almasty | P. lotor | raccoon |
25194 | Russia | almasty | U. arctos | brown bear |
25044 | Sumatra | orang pendek | Tapirus indicus | Malaysian tapir |
25035 | AZ, USA | bigfoot | P. lotor | raccoon |
25167 | AZ, USA | bigfoot | Ovis aries | sheep |
25104 | CA, USA | bigfoot | U. americanus | American black bear |
25106 | CA, USA | bigfoot | U. americanus | American black bear |
25081 | MN, USA | bigfoot | Erethizon dorsatum | N. American porcupine |
25082 | MN, USA | bigfoot | U. americanus | American black bear |
25202 | OR, USA | bigfoot | U. americanus | American black bear |
25212 | OR, USA | bigfoot | C. lupus/latrans/domesticus | wolf/coyote/dog |
25023 | TX, USA | bigfoot | Equus caballus | horse |
25072 | TX, USA | bigfoot | Homo sapiens | human |
25028 | WA, USA | bigfoot | U. americanus | American black bear |
25029 | WA, USA | bigfoot | C. lupus/latrans/domesticus | wolf/coyote/dog |
25030 | WA, USA | bigfoot | Bos taurus | cow |
25069 | WA, USA | bigfoot | Odocoileus virginianus/hemionus | white-tailed/mule deer |
25086 | WA, USA | bigfoot | Bos taurus | cow |
25093 | WA, USA | bigfoot | C. lupus/latrans/domesticus | wolf/coyote/dog |
25112 | WA, USA | bigfoot | Bos taurus | cow |
25113 | WA, USA | bigfoot | C. lupus/latrans/domesticus | wolf/coyote/dog |
Two of the samples identified give grounds for suspicion in that they are of American species but allegedly found in Russia, but it is the Himalayan samples from Ladakh, India and Bhutan which are again interesting from a biological evolutionary perspective.
Sequences derived from hair sample nos. 25025 and 25191 had a 100% match with DNA recovered from a Pleistocene fossil more than 40 000 BP of U. maritimus (polar bear) but not to modern examples of the species. Hair sample no. 25025 came from an animal shot by an experienced hunter in Ladakh, India ca 40 years ago who reported that its behaviour was very different from a brown bear Ursus arctos with which he was very familiar. Hair sample no. 25191 was recovered from a high altitude (ca 3500 m) bamboo forest in Bhutan and was identified as a nest of a migyhur, the Bhutanese equivalent of the yeti. The Ladakh hairs (no. 25025) were golden-brown, whereas the hair from Bhutan (no. 25191) was reddish-brown in appearance. As the match is to a segment only 104 bp long, albeit in the very conserved 12S RNA gene, this result should be regarded as preliminary. Other than these data, nothing is currently known about the genetic affinity of Himalayan bears and although there are anecdotal reports of white bears in Central Asia and the Himalayas, it seems more likely that the two hairs reported here are from either a previously unrecognized bear species, colour variants of U. maritimus, or U. arctos/U. maritimus hybrids. Viable U. arctos/U. maritimus hybrids are known from the Admiralty, Barayanov and Chicagov (ABC) islands off the coast of Alaska though in the ABC hybrids the mitochondrial sequence homology is with modern rather than ancient polar bears. If they are hybrids, the Ladakh and Bhutan specimens are probably descended from a different hybridization event during the early stages of species divergence between U. arctos and U. maritimus. Genomic sequence data are needed to decide between these alternatives. If these bears are widely distributed in the Himalayas, they may well contribute to the biological foundation of the yeti legend, especially if, as reported by the hunter who shot the Ladakh specimen, they behave more aggressively towards humans than known indigenous bear species.
So it's looking increasingly likely that there are bears from the Himalayas that share a female relative with the archaic bear found in northern Norway and which may possibly be a newly-discovered species. Whether they are the origin of the Yeti is still to be proven. The biological significance of this is that, if it is substantiated, it will illustrate a basic principle of evolution - how an isolated population is free to evolve in a unique direction and how environmental change such as the end of the Ice-Age can produce different evolutionary responses in different parts of the former range as populations become isolated. From a possibly widespread population of archaic U. maritimus we now have the polar bear and the brown bear (U. arctos) and a possible third species which, at least in its female line in its mtDNA is closer to the common ancestor than the other two sister species.
It's maybe worth repeating what I said last October:
So, creationists, you can now go around trying to impress people by asking, "If polar bears evolved out of ancient bears, why are there still ancient bears?". You'll be told, of course, by those who bother to answer you, that it's because they both evolved out of genetically separated populations, just like humans and the other apes did.
Rosa Rubicondior; Not Yeti? 17 October 2012
Footnote:
Bryan Sykes is author of a number of very readable books on human evolution and population genetics, including The Seven Daughters of Eve, Adam's Curse and Blood of the Isles.
Bryan Sykes is author of a number of very readable books on human evolution and population genetics, including The Seven Daughters of Eve, Adam's Curse and Blood of the Isles.
*© 2014 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0/, which permits unrestricted use, provided the original author and source are credited.
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