A New Theory for the Origin of Yeti

A few days ago, this abstract showed up on Dienekes' Blog and I've been trying to find a hook.

Altitude adaptation in Tibetans came from Denisovans

Altitude adaptation in Tibetans caused by introgression of Denisovan-like DNA

Emilia Huerta-Sánchez et al.

As modern humans migrated out of Africa, they encountered many new environmental conditions, including greater temperature extremes, different pathogens and higher altitudes. These diverse environments are likely to have acted as agents of natural selection and to have led to local adaptations. One of the most celebrated examples in humans is the adaptation of Tibetans to the hypoxic environment of the high-altitude Tibetan plateau. A hypoxia pathway gene, EPAS1, was previously identified as having the most extreme signature of positive selection in Tibetans and was shown to be associated with differences in haemoglobin concentration at high altitude. Re-sequencing the region around EPAS1 in 40 Tibetan and 40 Han individuals, we find that this gene has a highly unusual haplotype structure that can only be convincingly explained by introgression of DNA from Denisovan or Denisovan-related individuals into humans. Scanning a larger set of worldwide populations, we find that the selected haplotype is only found in Denisovans and in Tibetans, and at very low frequency among Han Chinese. Furthermore, the length of the haplotype, and the fact that it is not found in any other populations, makes it unlikely that the haplotype sharing between Tibetans and Denisovans was caused by incomplete ancestral lineage sorting rather than introgression. Our findings illustrate that admixture with other hominin species has provided genetic variation that helped humans to adapt to new environments. Link

In short, and without the genetic garbage, it would appear that a gene that encodes for high altitude adaption, and appears in high frequency in the Tibetans is the result of early interbreeding between anatomically modern humans and Denisovans, a prehistoric species of hominid known only from a few finger bones from Siberia, but whose complete DNA record has been determined from those bones. Thus, it seems likely that the gene originated in Denisovans and was transferred to humans via interbreeding.

It came to me today, that perhaps this means that Denisovans may be the origin of the Yeti myth. Did the Tibeten forefathers encounter a residual population of Denisovans living in the Himalayas with the EPAS1 gene, and lead to the "man bear" myth. Did a few acts of interbreeding with the "yeti" bring the genes that make the Tibetans master mountain men into the human gene pool? It's fun to speculate when you don't actually have to prove anything.

Let's go a little further with our speculation.  Do a few residual pockets of Denisovans cling to life in some of the out of the way places in the world to this day. If so, by now, they've certainly discovered that human populations are generally not in their best interests, and being advanced hominids, they're nearly as intelligent as humans, and would go to great lengths to stay concealed from humans. Did they also cross the Berengian isthmus, and give rise to a race of Sasquatch in American?

Probably not, but, God, it would be fun if it were all true.. . .

Wombat-socho has the great "Rule 5 Tuesday – Belated Independence Day Weekend Edition" up at The Other McCain.