The exact identity of the yeti, an ape-like creature, important to folklore and mythology in the Tibetan Plateau-Himalaya region is still surrounded by mystery. The authors of a recent Proceedings B article on the evolutionary history of brown bears used genetic analyses to show the phylogenetic relationships and evolutionary history of Himalayan and Tibetan bears, thus shedding light on the possible identity of the yeti. We spoke to lead author, Charlotte Lindqvist about this fascinating research and findings.
Tell us about yourself and your research?
I’m an Associate Professor in the Department of Biological Sciences at the University at Buffalo, currently a Visiting Associate Professor at Nanyang Technological University in Singapore. I am an evolutionary geneticist, broadly interested in understanding the processes and patterns of species diversification, and how it is impacted by hybridisation and responses to environmental perturbations, in both animals and plants. One of my research projects involves polar and brown bear evolutionary history and I am sequencing genomes of both modern and ancient, subfossil bears. I find it fascinating how such large and iconic animals display an excellent example of complex speciation in response to climatic changes. This is something we, today, can address much better than ever with genomic data.
What does your paper tell us?
The findings of our paper are two-fold. First, we conducted a comprehensive genetic survey to explore the identity of animal remains. These included bone, skin, hair and fecal samples that had been collected in the Himalayas and Tibetan Plateau and were thought by locals to have come from yetis. By analysing the DNA from these samples, we were able to directly determine that they belonged to local black and brown bears. Secondly, as our ultimate goal was to infer the evolutionary history of bears in the region, we sequenced mitochondrial DNA, including complete mitochondrial genomes from some of these animal remains, and reconstructed their phylogenetic history. We show that the Himalayan brown bear, which is a subspecies of brown bear, is the first-branching lineage of modern brown bears, while the Tibetan brown bear, another subspecies, diverged much later. The Himalayan black bear also appears to hold an isolated position among Asian black bears.
Did you discover anything surprising?
Because many of the samples we worked with were of unknown identity, it was exciting to discover that these samples were in fact related to local bears. Although it has previously been anecdotally associated with local bears, the exact identity of the yeti is still surrounded by mystery. A previous study, recently published in Proceedings B, and based on only two purported yeti samples and limited genetic data, had speculated that an unclassified, and possibly hybrid, bear species might be present in the region, but this preliminary finding had been questioned. Our results refute that finding and strongly suggest that the biological basis of the yeti legend is local brown and black bears, and not a mythical creature or previously unknown bear species.
We were also surprised to find the Himalayan brown bear placed at the base of the brown bear family tree as sister lineage to all other modern brown bears. Genetic relationships of most of the world’s brown bear populations have been fairly well studied but very limited data existed of the Himalayan brown bear and it was not clear how these endangered and elusive bears from the northwestern Himalayan region were related to other brown bear populations. It was a similar story with the Himalayan black bear. Our results indicate that both of these bear populations diverged early and experienced long isolation from other bear populations, likely in response to major glaciation events in the region.
What implications does your research have on the field?
To my knowledge, this study represents the most rigorous analysis to date of samples suspected to derive from anomalous or mythical ‘hominid’-like creatures, and it demonstrates that genetics will be able to unravel other, similar mysteries. In recent years, the techniques of recovering DNA from historical and ancient samples have vastly improved and our study also helps to demonstrate that biological samples archived in museums or private collections can significantly aid in our understanding of the genetic variation and phylogeographic patterns of rare and widespread species that may otherwise be difficult to get hold of.
I also hope that our study will help increase the attention on bears in this region. Both brown and black bears in the Himalayas are either vulnerable or critically endangered but not much is known about them. Our study helps placing these bear populations in a global perspective, e.g., they appear to hold important clues to the evolutionary history of bears around the world and likely also the climatic history of the geologically dynamic and young Himalayas and Tibetan Plateau. It is clear that increasing knowledge on their population structure and genetic diversity will not only be important for studies of worldwide brown bear populations but also for estimating population sizes and guiding conservation management strategies of bears in the region.
What made you submit to Proceedings B and what was your experience of the process?
An earlier study about the identity of purported yeti samples had been published in Proceedings B and I thought it would be an appropriate place to submit our paper. But also, I have long known about the journal as a highly respected journal that publishes excellent research of broad impact and felt our work could live up to the rigorous and high standards of the journal. Publishing in Proceedings B was a positive experience and I was impressed by the efficient and quick process.
Proceedings B is looking to publish more high-quality research articles and reviews in the field of evolution. If you have an idea for a review, we strongly encourage you to submit a proposal by completing our proposal template and sending it to the journal. Find out more information about the journal and the submission process.
Main image: Himalayan brown bear from the Deosai National Park, Pakistan. Image credit: Abdullah Khan, Snow Leopard Foundation