Refugia

Sometimes a population has effective adaptations that protect against a very serious local problem – a problem so serious that outsiders that don’t have those special adaptations cannot invade, at least not without a fair amount of gene flow from the locals. Due to tropical diseases, much of Sub-Saharan Africa was like that.

We know that one of the key alleles in the Tibetan altitude response comes from Denisovans, which implies that some Denisovans spent a long time at high altitude. Suppose that they occupied Tibet. Could modern humans have invaded Tibet? Even if they could, might it have taken much longer than elsewhere? Might Denisovans have lingered longer in Tibet than elsewhere?

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59 Responses to Refugia

  1. Greying Wanderer says:

    yetis, trolls, ogres, giants, goblins etc

    • dearieme says:

      On that basis leprechauns must be specially adapted for bogs.

      • Jacob says:

        I mean, really, can’t we be convinced that the Irish are actually pygmy Neanderthals?

        • dearieme says:

          How odd that leprechauns didn’t evolve snorkels to make bog living easier.

          • Jacob says:

            I had imagined their proboscis like that of a tapir- prehensile, therefore capable of holding a potato if their hands aren’t free. Perhaps we should ask the upstanding citizens of Mobile, Alabama.

        • A wee bit o' the leprechaun in me blood perhaps says:

          My working hypothesis until proven otherwise – the emerging genetics data will continue to show much of the Irish of today is Viking in origins, and that the original leprechaun stories were exaggerations and jokes told by the invaders about the natives. Over time as they inter-married and ~became~ the natives they cleaned up the stories. Somewhat.

  2. Jean-Paul says:

    w/ EPAS1 introgression into Tibetans, I’m convinced that Denisovans were around ~as long as Wrangel Island mammoths…i.e. within the realm of recorded history, and certainly within the time span of modern human mythology…

  3. Cpluskx says:

    You can write a good story about this. Superhumans living at extreme high altitude, normal humans are attacking and trying to conquer their mountains but unable to do so (altitude sickness)

  4. I wonder if there are adaptation which might protect Europeans from welfare dependency?

    • The G_Man says:

      If so, they’re not being selected for….

    • tautology says:

      More importantly we should explore the implications of this thought on how small cities in the 11th century constituted refugia that prevented Ghuelfs from settling there. My best guess is that small cities smeeled relly bad and the Ghibellines were resistant to that smell, imperial grovelers that they are.

  5. tommy says:

    Out of curiosity, would high altitude genes be useful in other situations where a lack of oxygen could be an issue? Would a spelunker or a free diver benefit from such genes?

    • dearieme says:

      Why not check populations that used to do pearl-diving?

    • Smithie says:

      There’s got to be some sort of trade off. Lower fitness at low altitude which would mean the gene probably doesn’t show up in pearl divers, though maybe it would be useful to them. Of course, there’s probably a limit to how useful it would be. If everyone could dive easily, it wouldn’t be a skill, and you’d crash the market.

      It’s fun to think of the reverse: low altitude traits that may have been useful at high altitude. Maybe troops of barrel-chested Neanderthal-human hybrids were the ones who conquered the Tibetan Denisovans.

  6. Space Ghost says:

    OK, but how do you explain the Sasquatch.

    • Zimriel says:

      Mangy and/or deformed bears. Also, misanthropic bearded mountain men gone full [i]Shrek[/i] and chasing sidewindin’ bushwackin’, hornswagglin’ cracker croaker city-slickers off their land.

      Rivved!

      • Ursiform says:

        A woman in Southern California is suing the Park Service because a ranger told her her big foot sighting was just a bear. She is a big foot activist, and claims the denials put both the big foot population and people at risk.

      • Jim says:

        The Texas Wildlife commission has stated that all supposed chupacapra corpses brought to their attention turned out to be coyotes with mange.

    • Olorin says:

      Same way we explain the Pacific Tree Octopus, or the Flatwoods Monster or Mothman of WV.

      FWIW, city people aren’t hard to disorient/scare in the high/back country.

      Even forest instincts can get fooled. Around age 19 I was chased by an 8-foot tall monster in the (TN) Roan highlands. As the fastest walker I was out ahead of my backpacking posse…and hit Olympic sprinter speeds backtracking to join them even with my 55-lb pack. I tried to report calmly that I’d been charged by…something large, loud, flashing, clacking, and screeching, but they whiffed my adrenaline and it triggered theirs.

      We all calmed down then moved forward in a unified patrol, on hyper alert. As we all approached the trail turn where I’d been charged, six or eight little beaked fluffballs ran toward us with eager curiosity, straight up the middle of the trail. Papa ruffed grouse–all of a pound or so in mass–didn’t charge me this time. He jumped up on a log and issued a warning to his hen, who clucked alarm to the chicks, so they returned to her in the groundcover, and then froze and disappeared.

      The last surviving member of that posse and I were still laughing about this a few years ago, before his death. I can still see my brain’s image of the clashing mandibles, somewhere up over my head, and easily big enough to envelop my skull.

      Doesn’t take much adrenaline to fill in all sorts of blanks. The avian maniraptors have a good quarter billion years of survival strategies under their feathery belts, including projecting their inner T-rex into primate fear centers. We humans have considerably fewer. And we who are losing our human biodiversity refugia at an accelerated clip have learned that you don’t need beards or misanthropy to keep urban hive invaders on their toes and questioning their fantasies of portable glaring blaring comfort uber alles…in others’ back yards.

    • Octavian says:

      One reason given to doubt the existence of Sasquatch is that for a breeding population to exist we would find more evidence of them.

      But consider! Human beings are clearly neotenous – the genetic pathway that leads to muzzles, thick body hair, etc., in other primates is missing. But what of the few unfortunates where a mutation has reenabled that pathway? At puberty they would, in addition to the normal changes, grow a muzzle, extensive body hair and probably increase in overall body size, including the brain.

      Cast out from their homes as being the spawn of Satan, they would wander the paths less trodden by normal human beings – bigger, stronger and smarter than ourselves, so we wouldn’t have a hope of catching one.

      Send a sample of hair or blood to a lab and it would just come back ‘human’. So few of them we would not find the bones. And that, my friends, is why Sasquatch, Yeti and so on, do in fact exist, contrary to popular opinion!

  7. Mis(ter)Anthrope says:

    I’m sure why, but to even think such thoughts must be racist!

  8. pyrrhus says:

    Perhaps the Yeti, of which there have been some sightings, is a Denisovan offshoot?

  9. sam57l0 says:

    Are the Andean indians Denisovians?

    • Rainforest Giant says:

      If I remember correctly, they have none of the Tibetan adaptations.

      • A different set of adaptations. Spanish did poorly at the higher elevations, lots of death in childbirth.

        • Frau Katze says:

          The highlands of the Andes were positively healthy compared to the malaria- and yellow fever-infested coasts. Only the Africans could live and function there. The natives seem to have been completely wiped out in many places.

          The Africans must some kind of protection (sickle cell was one, discussed in a previous post).

          I’m not sure about the highlanders. Maybe they have an adaption for altitude too. In the present day, there seems to be quite few natives living there.

          The Europeans did best at non-tropical latitudes and that’s where most of them live today.

  10. Jacob says:

    I had nearly the same thought when I saw a headline proclaiming that Denisovans may have donated genes to us twice. The first sweep across Eurasia must have been incomplete. I wondered if the Old Asians never made it past some latitude in Siberia because the Denisovans had way better adaptations to the cold.

    Speaking of which, do you know if Eskimo north of the treeline have a difficult time getting potable water during the winter? I think it could explain that CPTI mutation.

    • Frau Katze says:

      They must have burned fat found in marine life. I can’t think of any other method.

      http://www.athropolis.com/arctic-facts/fact-kudlik.htm

      Using fire would have been standard when the Eurasions crossed the then-existing land bridge. The land bridge was pretty far north itself. Techniques would have had time to develop.

      We don’t hear about it now because it’s no longer necessary.

      That far north area must be one of the most inhospitable places in the world for humans.

      They had no plant food whatsoever. Article discussing adaptation to such a diet,

      http://www.hfsp.org/frontier-science/awardees-articles/how-inuit-adapted-life-arctic

      • Jacob says:

        They’ve been known to use reindeer fat in Kudliks as well but it was much less common than seal fat. Either way, literally burning through their food supply is the only way I know they got water to drink. I’m wondering if running out of water might’ve been a bigger threat than running out of food for some period in their evolutionary history. I wonder how much of their food supply had to be burned in order to yield how much of their water supply?

  11. Halvorson says:

    It has to be these people, the location and date are too perfect:
    https://en.wikipedia.org/wiki/Red_Deer_Cave_people

  12. Don’t Tibetans have some Denisovan genes?

    I’ve also read that there was some Denisovan genetic influence in South Asia. Hoping to find out more about it at some point to help Indians identify their racial origins.

    redpillindian.blogspot.com

  13. Han Chinese birth weight lower then Tibetan natives, and O2 saturation of infants also lower. At the end of the article there is a bit on Spanish (non)adaptation to altitude in Bolivia after 400 years.
    http://www.redorbit.com/news/health/1113411744/chinese-immigrants-are-having-a-hard-time-reproducing-in-high-altitudes-122915/

    • Frau Katze says:

      Interesting. But the Han have a very good reason for hanging onto Tibet: water. I read a whole (interesting) book about water management in Asia. The Han are dependent on Tibetan water.

      Despite the considerable difficulties of the Han at high altitude they still have Tibet over 50 years after seizing it. Why?

      Perhaps the Tibetans can survive at high altitude but at some cost. Perhaps it affects fighting abilities. They can hang on, but only just. At the limit of endurance.

      • ChrisA says:

        I (white Caucasian) have spent extended periods at above 20k ft mountaineering without problems, (of course I was younger then). I am sure that people from any part of the world can do well enough to fight locals with modern weaponry at such altitudes as Lhasa which is only at 11k ft.

        • Ursiform says:

          I’ve known fit white people who have trouble hiking at 8 kft. Your mileage will vary.

        • Pincher Martin says:

          I spent a week in Tibet about ten years ago. I was never higher than 17,000 feet (when crossing the passes) and usually no higher than 13,000 feet. I even occasionally dropped down to lower than 9,000 feet in places like Nyingchi prefecture.

          I was sick the entire week, even though I had spent the previous few days hiking in Sichuan province in places where the average elevation was approximately 9000 feet above sea level. I thought first visiting Sichuan was helping me to acclimate to Tibet’s even higher elevations.

          Didn’t happen. I was fine in Sichuan province and sick as a dog in Tibet the following week. I threw up in Lhasa after my first breakfast and hugged an oxygen bottle for the rest of the morning. I managed to pull myself together and gut out the remaining six days of my tour. But I didn’t fully recover until I returned to Hong Hong. I was never so happy to see the ocean.

      • Ursiform says:

        Having once controlled it the Chinese government can’t give it up. It would look too much like weakness. Same reason many governments don’t give up regions that are more trouble than they are worth.

        China could surely cut a deal with Tibet for water. Tibet can’t sustain a huge population, and the Han are moved there more to control the area than because it provides a significant population relief for the rest of China.

      • Pincher Martin says:

        Despite the considerable difficulties of the Han at high altitude they still have Tibet over 50 years after seizing it. Why?

        Disparities in numbers, disparities in modern weaponry, Tibetan quislings, and the PLA soldiers don’t have to be permanently stationed in Tibet in order to control the region – they can be rotated in.

        But the Sinicization of Tibet has been greatly slowed by the region’s elevation. That becomes obvious if you look at the neighboring autonomous region of Xinjiang where the Uighers are getting swamped by the migrating Han. While there are historical differences between Han settlement of Tibet and Xinjiang, both places had similarly low numbers of Han Chinese in 1950 when the Chicoms had just taken over in Beijing and were able to gradually reassert China’s control over the two regions. Look at them now.

  14. Smithie says:

    The Ottomans had a pretty hard time with Montenegro, and the Tibetan Plateau does look quite a bit more formidable.

    I guess it would all depend on what the other factors were. How did ancient human pioneers operate? What was their social group size vs. Denisovans? How did their weapons compare? How many effective entryways are there into the plateau? Did human males bring their women with them, or operate for years without them?

    I think that last question would probably be the most important question of all. It is easy to imagine a high death rate for babies or women in childbirth giving a band the spooks and making an area taboo. Meanwhile the plateau would probably have a certain regenerative capacity for Denisovan numbers to make up for seasonal incursions.

  15. Smithie says:

    One of the reasons Denisova Cave is so interesting to me is the Neanderthal found inbetween Denisova layers. It is a pity we don’t have have a more complete Denisova skeleton to give an idea of their physical abilities. The idea of ancient humans and other hominins battling it out really captures the imagination in a way that even the dinosaurs don’t.

  16. Anonymous says:

    It’s a likely hypothesis that Denisovans lasted longer at these higher altitudes. I have been thinking where in their entire range where their bones and the DNA within them would have most likely be preserved and cold limestone caves in these high altitude locations would be the place. They have not been carefully combed through like the limestone caves in Europe where the Neanderthal bones have been found.

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