Tibetans breathe thin air because of extinct cavemen ancestors?

July 2, 2014 12:41 PM

A new paper in Nature suggests the gene variant that allows Tibetans to thrive at high altitudes may have arisen in the mysterious Denisovans, an extinct branch of hominid that co-existed with modern humans and Neanderthals. Denisovans were discovered through DNA analysis of a single bone from a cave in Siberia. Popular article in Slate. Just as Neanderthal ancestry contributed 1-4% of genes to modern people with ancestry outside of sub-Saharan Africa, Denisovan ancestry lives on in Southern Asia, and as the new research suggests, conferred benefits to the people of Tibet. From links here and here you can download the DNA letters for the first Denisovan discovered, along with a report generated based on personal genomics analysis.
posted by Schmucko (12 comments total)

Very cool.
posted by triage_lazarus at 12:45 PM on July 2, 2014 [3 favorites]

Previously on the Denisova cave. It's still a wild place a last refuge of the ice age.
posted by stbalbach at 12:46 PM on July 2, 2014

So that's why Alexis Denisof can breathe in vacuum. I always wondered.
posted by Iridic at 12:49 PM on July 2, 2014 [7 favorites]

Yeti genes.
posted by 2bucksplus at 12:49 PM on July 2, 2014 [2 favorites]

I read Denisovan ancestry was primarily found in Melanesians. Southern Asia is the Indian subcontinent, right? I don't think that's where the traces of ancestry were found.
posted by ChuckRamone at 12:51 PM on July 2, 2014

ChuckRamone, perhaps I should have said Southeast Asia, or specified Papua New Guinea and Australia, or Melanesians, etc. Kind of neat that though first discovered in Siberia, the modern DNA traces are so far away.
posted by Schmucko at 12:56 PM on July 2, 2014

Yeah, I think that surprised the researchers who expected to find it mostly in eastern Eurasia, their assumed original geographical range. Apparently the Denisovans were pushed out to or migrated out to Oceania, or mostly interbred with modern humans there.
posted by ChuckRamone at 1:03 PM on July 2, 2014

The new analysis shows that the particular sequence of genes encoding for how EPAS1 functions in Tibetans was not a random, auspicious mutation...

Yes it was.
posted by ChurchHatesTucker at 1:28 PM on July 2, 2014 [5 favorites]

John Hawks' blog has a ton of cool stuff on the Denisovan cave discoveries.

It is kind of like the old parable about the six blind Indian gurus arguing about the nature of the elephant that one thinks is a wall, one thinks is a tree, one thinks is a snake, &c.
posted by bukvich at 1:30 PM on July 2, 2014 [1 favorite]

Peruvians developed the same ability to work and thrive at high elevations. But they were certainly descended, or ascended in this case,. from sea level ancestors.

It would be interesting to compare the genomes.
posted by Repack Rider at 6:50 PM on July 2, 2014 [1 favorite]

Can someone explain how we can be so sure about Denisovans existing from a single bone? I understand that DNA is involved but what about that DNA tells us that it must be a new species (or sub-species)? (Yes I RTFA). I know next to nothing about genetics (other than what you learn in a a freshman bio class and popular media). Happy to take this to ask if this is a derail.
posted by runcibleshaw at 7:50 PM on July 2, 2014

I recommend the book Neanderthal Man by Svante Paabo. He's probably the major figure in the sequencing of ancient hominin species. It was written with a popular audience in mind and explains the whole process. The book is mostly about Neanderthal sequencing but also goes a bit into Denisovans.
posted by ChuckRamone at 8:33 PM on July 2, 2014 [1 favorite]