5 ms·

Adaptation to high-altitude hypoxia on the Tibetan Plateau

43 points by amichail 2y ago

photochemsyn 2y ago
If you read the papers related to the work it's really not all that clear how much of this is genetic (inherited) evolution or just adaptation from birth to different environmental conditions, i.e. any child born and raised at high altitude might display such adaptations, regardless of parentage. https://www.pnas.org/doi/10.1073/pnas.0701985104 https://www.pnas.org/doi/10.1073/pnas.0701985104 > "Tibetans (the study sample were Sherpas, an ethnic group that emigrated from Tibet to Nepal ≈500 years ago) who are born and raised at high altitude have higher capillary density in muscles as compared with Andean high-altitude natives, Tibetans born and raised at low altitude, or lowlanders." > "Are These Functional Adaptations Heritable? To evaluate the hypothesis that natural selection accounts for the functional physiological characteristics of Tibetan highlanders relative to Andean highlanders or of highlanders relative to lowlanders, a primary consideration is the presence of heritable variation in the traits under consideration. However, the genetic underpinnings of these quantitative traits are mostly unknown (with the exception of nitric oxide). These traits are also influenced by individual characteristics, including age and sex." > "With respect to identifying specific genetic loci contributing to high-altitude functional adaptation, efforts so far have not been successful." An accurate headline would replace 'are evolving' with 'might be evolving' for this work.
yard2010 2y ago
Interestingly enough, the source[0] comparing the andean evolution and the tibetan evolution which are a bit different - which makes this a case of convergent evolution. TIL the human body for the last billion years does not store oxygen in the mitochondria, despite the wide swings in the oxygen levels in the atmosphere, probably due to its destructive effects. In other words: the air is toxic. We breathe it enough, we die. [0] https://www.pnas.org/doi/10.1073/pnas.0701985104 https://www.pnas.org/doi/10.1073/pnas.0701985104
- echelon 2y ago
  > the air is toxic. Oxygen is the oxadative species that drives our biochemistry. It's a fuel. Oxygen is highly reactive. It is a fantastic evolutionary gradient as it has tons of free and readily available energy to harness. But of course it's also what also wears us down by putting oxidative stress on our cells, DNA, and molecular biology. It causes all sorts of damage as a byproduct of what it is. Oxygen is life and death. The particulates suspended in the air are yet another problem ...
- blackeyeblitzar 2y ago
  > We breathe it enough, we die. Isn’t this true of anything in excess? For gases - nitrogen, oxygen, carbon dioxide, etc all have this effect. In fact some states are using nitrogen for executions, although it’s not exactly humane (warning: https://en.wikipedia.org/wiki/Execution_of_Kenneth_Eugene_Smith https://en.wikipedia.org/wiki/Execution_of_Kenneth_Eugene_Sm...).
  - thaumasiotes 2y ago
    > gases - nitrogen, oxygen, carbon dioxide, etc all have this effect What effect are you talking about? Those gases all have very different, unrelated effects. > In fact some states are using nitrogen for executions The nitrogen isn't harmful; the cause of death is the amount of oxygen (zero), not the amount of nitrogen (slightly more than normal). > although it’s not exactly humane That's just propaganda. Exceptionally dishonest propaganda. You should be ashamed to repeat it.
    - blackeyeblitzar 2y ago
      > That's just propaganda. Exceptionally dishonest propaganda. Cool. Got any reasoning as to why? Here’s mine: [quote] An autopsy of Smith's body was conducted by the Alabama Department of Forensic Sciences. The autopsy showed Smith exhibited signs of negative-pressure pulmonary edema, had "dark maroon blood" and fluid present in his lungs along with "marked congestion", and had "frothy fluid" in his trachea. Another death row inmate scheduled to die by nitrogen hypoxia in Alabama in November 2024, Carey Dale Grayson, hired an expert to analyze Smith's autopsy results in August 2024. After a review, the expert called the results "highly concerning."[33][34] Dr. Brian McAlary, an anesthesiologist, wrote in an argument on Grayson's behalf that Smith likely panicked due to an automatic response to the inability to breathe oxygen and that Smith's panic may have been avoided if he had been given a sedative prior to his execution. A second expert, Dr. Thomas Andrew, the chief medical examiner of New Hampshire, agreed that Smith should have been sedated before his execution because nitrogen hypoxia introduces "a sense of the absence of oxygen, air hunger, and all of the panic and discomfort that is part and parcel of that way of dying."[34] Volker Türk, the United Nations High Commissioner for Human Rights, condemned Alabama's use of nitrogen gas to administer Smith's death penalty and stated that the method had amounted to a potential form of torture and degrading punishment.[35][36] [end quote] > You should be ashamed to repeat it. Such ad hominem attacks are against the site guidelines.
dang 2y ago
[stub for offtopicness]
- spacemark 2y ago
  Humans are evolving right before our eyes, everywhere, always. Still an interesting article, though!
  - dash2 2y ago
    Yup (blowing my own trumpet): https://link.springer.com/article/10.1007/s10519-022-10107-w?1 https://link.springer.com/article/10.1007/s10519-022-10107-w...
  - Mistletoe 2y ago
    I wonder what evolutionary pressures are working on modern humans right now and how they will shape the future?
    - com 2y ago
      John Hawks, a paleoanthropologist, regularly makes the point [0] that human evolution has accelerated enormously in the last 50k years. Lactase metabolism is new, in the last 19k years. European skin colours and blue eyes appear to be very recent too, maybe 3.5k years. Almost certainly there are all kinds of super interesting human evolutionary changes that are occurring now, with our huge population that won’t be visible for thousands of years… [0] at least since this https://johnhawks.net/weblog/our-new-paper-on-why-human-evolution-accelerated/ https://johnhawks.net/weblog/our-new-paper-on-why-human-evol...
      - yard2010 2y ago
        This makes me sad every time - I know for a fact that mountains are evolving, but in my lifetime the mountains are just mountains. Still. Not changing a bit unless I'm looking really really close (which means that it's not the mountain that changes, but merely its surface).. So the same with humans. I don't care about living forever, I just want to see what happens in 10k years. Just out of curiosity.

43 points by amichail 2y ago

If you read the papers related to the work it's really not all that clear how much of this is genetic (inherited) evolution or just adaptation from birth to different environmental conditions, i.e. any child born and raised at high altitude might display such adaptations, regardless of parentage. https://www.pnas.org/doi/10.1073/pnas.0701985104 https://www.pnas.org/doi/10.1073/pnas.0701985104 > "Tibetans (the study sample were Sherpas, an ethnic group that emigrated from Tibet to Nepal ≈500 years ago) who are born and raised at high altitude have higher capillary density in muscles as compared with Andean high-altitude natives, Tibetans born and raised at low altitude, or lowlanders." > "Are These Functional Adaptations Heritable? To evaluate the hypothesis that natural selection accounts for the functional physiological characteristics of Tibetan highlanders relative to Andean highlanders or of highlanders relative to lowlanders, a primary consideration is the presence of heritable variation in the traits under consideration. However, the genetic underpinnings of these quantitative traits are mostly unknown (with the exception of nitric oxide). These traits are also influenced by individual characteristics, including age and sex." > "With respect to identifying specific genetic loci contributing to high-altitude functional adaptation, efforts so far have not been successful." An accurate headline would replace 'are evolving' with 'might be evolving' for this work.

yard2010 2y ago

Interestingly enough, the source[0] comparing the andean evolution and the tibetan evolution which are a bit different - which makes this a case of convergent evolution. TIL the human body for the last billion years does not store oxygen in the mitochondria, despite the wide swings in the oxygen levels in the atmosphere, probably due to its destructive effects. In other words: the air is toxic. We breathe it enough, we die. [0] https://www.pnas.org/doi/10.1073/pnas.0701985104 https://www.pnas.org/doi/10.1073/pnas.0701985104

echelon 2y ago
> the air is toxic. Oxygen is the oxadative species that drives our biochemistry. It's a fuel. Oxygen is highly reactive. It is a fantastic evolutionary gradient as it has tons of free and readily available energy to harness. But of course it's also what also wears us down by putting oxidative stress on our cells, DNA, and molecular biology. It causes all sorts of damage as a byproduct of what it is. Oxygen is life and death. The particulates suspended in the air are yet another problem ...
blackeyeblitzar 2y ago
> We breathe it enough, we die. Isn’t this true of anything in excess? For gases - nitrogen, oxygen, carbon dioxide, etc all have this effect. In fact some states are using nitrogen for executions, although it’s not exactly humane (warning: https://en.wikipedia.org/wiki/Execution_of_Kenneth_Eugene_Smith https://en.wikipedia.org/wiki/Execution_of_Kenneth_Eugene_Sm...).
- thaumasiotes 2y ago
  > gases - nitrogen, oxygen, carbon dioxide, etc all have this effect What effect are you talking about? Those gases all have very different, unrelated effects. > In fact some states are using nitrogen for executions The nitrogen isn't harmful; the cause of death is the amount of oxygen (zero), not the amount of nitrogen (slightly more than normal). > although it’s not exactly humane That's just propaganda. Exceptionally dishonest propaganda. You should be ashamed to repeat it.
  - blackeyeblitzar 2y ago
    > That's just propaganda. Exceptionally dishonest propaganda. Cool. Got any reasoning as to why? Here’s mine: [quote] An autopsy of Smith's body was conducted by the Alabama Department of Forensic Sciences. The autopsy showed Smith exhibited signs of negative-pressure pulmonary edema, had "dark maroon blood" and fluid present in his lungs along with "marked congestion", and had "frothy fluid" in his trachea. Another death row inmate scheduled to die by nitrogen hypoxia in Alabama in November 2024, Carey Dale Grayson, hired an expert to analyze Smith's autopsy results in August 2024. After a review, the expert called the results "highly concerning."[33][34] Dr. Brian McAlary, an anesthesiologist, wrote in an argument on Grayson's behalf that Smith likely panicked due to an automatic response to the inability to breathe oxygen and that Smith's panic may have been avoided if he had been given a sedative prior to his execution. A second expert, Dr. Thomas Andrew, the chief medical examiner of New Hampshire, agreed that Smith should have been sedated before his execution because nitrogen hypoxia introduces "a sense of the absence of oxygen, air hunger, and all of the panic and discomfort that is part and parcel of that way of dying."[34] Volker Türk, the United Nations High Commissioner for Human Rights, condemned Alabama's use of nitrogen gas to administer Smith's death penalty and stated that the method had amounted to a potential form of torture and degrading punishment.[35][36] [end quote] > You should be ashamed to repeat it. Such ad hominem attacks are against the site guidelines.

dang 2y ago

[stub for offtopicness]

spacemark 2y ago
Humans are evolving right before our eyes, everywhere, always. Still an interesting article, though!
- dash2 2y ago
  Yup (blowing my own trumpet): https://link.springer.com/article/10.1007/s10519-022-10107-w?1 https://link.springer.com/article/10.1007/s10519-022-10107-w...
- Mistletoe 2y ago
  I wonder what evolutionary pressures are working on modern humans right now and how they will shape the future?
  - com 2y ago
    John Hawks, a paleoanthropologist, regularly makes the point [0] that human evolution has accelerated enormously in the last 50k years. Lactase metabolism is new, in the last 19k years. European skin colours and blue eyes appear to be very recent too, maybe 3.5k years. Almost certainly there are all kinds of super interesting human evolutionary changes that are occurring now, with our huge population that won’t be visible for thousands of years… [0] at least since this https://johnhawks.net/weblog/our-new-paper-on-why-human-evolution-accelerated/ https://johnhawks.net/weblog/our-new-paper-on-why-human-evol...
    - yard2010 2y ago
      This makes me sad every time - I know for a fact that mountains are evolving, but in my lifetime the mountains are just mountains. Still. Not changing a bit unless I'm looking really really close (which means that it's not the mountain that changes, but merely its surface).. So the same with humans. I don't care about living forever, I just want to see what happens in 10k years. Just out of curiosity.