Humans Are Evolving Right Before Our Eyes on the Tibetan Plateau

(sciencealert.com)

33 points | by amichail 4 days ago ago

67 comments

  • spacemark 12 hours ago

    Humans are evolving right before our eyes, everywhere, always.

    Still an interesting article, though!

    • dash2 12 hours ago
    • solardev 11 hours ago

      Our grandkids will have giant thumbs and tiny brains...

      • johannes1234321 11 hours ago

        Only if giant thumbs are useful in using tinder to reproduce more.

    • Mistletoe 12 hours ago

      I wonder what evolutionary pressures are working on modern humans right now and how they will shape the future?

      • com 11 hours 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-evol...

        • yard2010 11 hours 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.

          • dwaltrip 10 hours ago

            There’s a really great sci fi book that touches on this, I’m blanking on the name. They can “bobble” up regions of space which basically freezes time for a duration in that region. Highly recommend.

            • joak 9 hours ago

              Vernor Vinge - Marooned in Realtime

              • com 34 minutes ago

                And, spoiler alert, it’s not good, really!

      • hn_throwaway_99 11 hours ago

        If you look at the complete collapse of fertility rates in the developed world, that is probably the strongest evolutionary pressure humans have faced for millennia.

        It is a bit weird to me that the scientific press doesn't talk more about how evolutionary pressure applies here. I think that people are wary to talk about this because it can end up sounding like social Darwinism, or that they believe "Idiocracy" was a scientific documentary.

        But it's inescapable, for example, that education rates are now strongly negatively correlated with fertility. While "level of education" is obviously not inherited genetically, I don't think it's too much of a stretch to hypothesize that genetic factors play a role in someone's educational attainment. And, currently, the more education you get, the less likely you are to reproduce (statistically, of course).

        Sex evolved to feel really good because for most of human history having sex would usually, eventually lead to babies. Reliable birth control has fundamentally broken that link. Similarly, when a major factor preventing you from reproducing was starving to death, being smarter or cleverer was an evolutionary advantage. I'd argue that advantage no longer exists.

        Another simple anecdote: I recently went to my uncle's funeral, and his family was very religious (Catholic). My father, on the other hand, rejected religion and raised us all atheists. My father has 6 descendants, my uncle 24. Again, "religiosity" is not a genetically inherited trait, but I think it would be foolish to believe genetic predisposition plays 0 role.

        I say all this just to highlight that, eventually, the "collapse in birthrates" will take care of itself - people with a strong desire and ability to procreate will outcompete, at least in terms of offspring survival, their peers. This will have a huge, profound effect on world society that most academics are too scared to talk about.

        • swatcoder 10 hours ago

          > But it's inescapable, for example, that education rates are now strongly negatively correlated with fertility. While "level of education" is obviously not inherited genetically, I don't think it's too much of a stretch to hypothesize that genetic factors play a role in someone's educational attainment. And, currently, the more education you get, the less likely you are to reproduce (statistically, of course).

          Far from inescapable, this is just a phantom of noisy data.

          It's easy to find statistically communicative population slices where family size is quite high and so is level of education (ignoring that "level of education" is a culturally specific and disputable measure in the first place).

          What we really see is that integration into the modern US/EU-inspired "universal middle class" urban culture, which now spans the globe, seems to correlate with lower birth rates and family sizes. But there are countless factors contributing to what makes that culture unique and that could easily be playing a role in the birth rates and family sizes.

          That said, it does suggest that the this "modern" culture needs to induct outsiders in order to maintain its scale since its proving relatively poor at growing its own population among insiders. What that means for the future is unclear, and if you're personally all in the on the "modern", it can easily look concerning or even bleak in the way you describe.

          • dash2 7 hours ago

            You're mistaken. Polygenic scores for educational attainment correlate negatively with fertility in the US, UK and elsewhere (in fact, AFAIK everywhere it has been tested). So it's not just because people in poor countries have more kids.

            Note also that natural selection is about correlation not causality. If an lab accident blows up MIT, that will select against intelligence, even though intelligence wasn't causal.

        • thinkingtoilet 11 hours ago

          I highly doubt birth control has altered the selection process in humans in the span of two or three generations.

          I think you're right for the wrong reasons. Correlation does not equal causation. I think it's very clear it's our modern lifestyle. Our diet. Many of us are over weight. Most of us are sedentary. We're consuming higher percentage alcohol and weed. We're consuming other drugs. There are microplastics in our blood stream and the food we eat. There are chemicals like BPAs that were in our products for years before we removed them. Pollution. The list goes on. I would rule out these factors first before ever considering the idea that evolution is at play.

          • hn_throwaway_99 11 hours ago

            > Correlation does not equal causation.

            The fact that you have said this makes me think you have misunderstood my point.

            I am not arguing that genetic differences are responsible for any change over the past couple generations. I am strongly arguing that there is now an enormous new selection pressure, i.e. a new factor that strongly affects fertility rates, and over time (and, perhaps a very long time) that genetic inheritance will respond to that selection pressure. That is inherently how evolution works.

            People love to say "correlation is not causation", but all evolution really works with in the first place is correlation. That is, the environment changes, and then organisms that happen, through "the genetic lottery", to not be able to reproduce in that new environment are outcompeted by those organisms that do. My argument is that the environment that determines whether humans reproduce has changed drastically over the past ~100 years or so, and that this will affect which genes are likely to be more prevalent in the future. I am not arguing this genetic change has already happened.

        • soperj 11 hours ago

          > But it's inescapable, for example, that education rates are now strongly negatively correlated with fertility.

          You can easily say that city dwelling is strongly correlated with higher education rates, and higher noise pollution, therefore high noise pollution is strongly negatively correlated with fertility. Correlation doesn't equal causation.

          > Reliable birth control has fundamentally broken that link.

          Reliable birth control has severely reduced unwanted pregnancy, but there's a whole host of people who would like to have children that can't.

      • swatcoder 11 hours ago

        Among them, eventually, will be modern medicine if we manage to preserve it long enough and share it widely enough.

        By suppressing the consequence of genetic predispositions and vulnerabilities, it lets those genes propagate more freely and invisibly than they would have been doing before. It helps individuals and communities today in a way we can't possibly refuse, but sets up the species to become perpetually dependent on an elaborate, brittle medical infrastructure. Genetic engineering and eugenics could eventually address that, but those invite scifi horrors of their own. We seem to have set ourselves into a bit of a trap.

        • gruez 11 hours ago

          >but sets up the species to become perpetually dependent on an elaborate, brittle medical infrastructure

          How is this any different than the transition from hunter-gatherers to agriculture caused us to "become perpetually dependent on an elaborate, brittle agricultural infrastructure"?

          • swatcoder 11 hours ago

            Only in scale and intensity.

            Agriculture took hold in numerous civilizations and indeed introduced one of the primary threats of collapse for those civilizations. Throughout history, we can see civilizations collapse when their dependence on agriculture faltered, which happened often enough.

            But neither the technology (agriculture) nor its failures (blight, famine, etc) were universal and so it hadn't become a threat to the species as a whole.

            Modernity, however, has become aggressively global and more successfully universalizing. We not only invite every community into it, we insist they do so for their own good. Further, its technological contrivances (and therefore their brittleness) are more intense because of industrialization and later accelerating technology. As it continues to progress and expand, it brings the whole species into its gamble and raises the stakes of that gamble at the same time.

        • fallingknife 11 hours ago

          Ths "scifi horrors" of genetic engineering are entirely made up. Those things just aren't profitable, so they won't get done.

          • wizzwizz4 11 hours ago

            Most wars cost more than the expected return-on-investment. Some people value horrors over money.

            • digging 4 hours ago

              I don't think you've interpreted that quite right. Modern wars aren't funded by the bank accounts of the people profiting from them. War is a wealth transfer to the top.

      • saalweachter 11 hours ago

        The biggest thing we're doing now is accumulating a huge amount of genetic diversity, full of all sorts of novel mutations and interesting admixtures.

        It's hard to know what genes or traits will be advantageous over the next centuries. The biggest place where our technological advantage still has large gaps that our biology can compensate is disease, and there it's almost random -- a gene that results in a novel protein which is normally advantageous or disadvantageous might have the opposite effect if it makes you exceptionally vulnerable or resistant to a new disease.

      • Ekaros 10 hours ago

        I could see plastics, chemicals, for-ever chemicals and in general various pollutants leading various pressures on reproduction. So on medium term there could be pressure for genetics that handle those better.

      • nickdothutton 11 hours ago

        Ability to write good dating profiles which appeal to the algorithm.

        • Y_Y 11 hours ago

          You know you have to do even more once you get a reply?

          • soperj 11 hours ago

            doing less generally works better.

      • MichaelZuo 11 hours ago

        I’ve heard human jaw muscles are becoming smaller and weaker as there’s less need to chew for prolonged periods of time.

        • abyssin 11 hours ago

          But is there an evolutionary pressure in this direction because of the decrease in need? That would be Lamarckian then. I wonder if certain traits need evolutionary pressure to stay stable, and otherwise degenerate in some specific direction.

          • jkrems 11 hours ago

            Many (most?) traits require energy to develop and maintain. A stronger muscle will need more energy so there's always pressure to reduce it. That pressure may just be countered by pressures in other directions.

          • Y_Y 11 hours ago

            Something something opportunity cost? If you can allocate your next bit of energy and protein to something with better bag-for-buck than a jaw muscle then that should be an evolutionary advantage.

            • actionfromafar 11 hours ago

              What is better bang for buck? Pretty small buck too.

              • Y_Y 6 hours ago

                More expected (over ensemble of specimens) evolutionary "fitness" per unit of whatever you need to expend to make a jaw muscle a bit stronger. The buck is small because we're doing optimization calculus.

        • Ekaros 10 hours ago

          One thing to consider is that some things might not be genetic, but environmental. I think jaw muscles are one such thing and short-sightedness might be other. First caused by food we eat and the other by less natural light and less time spend outside in childhood.

          I think there might be more of these effects.

      • nonameiguess 11 hours ago

        White skin will probably go away in a few thousand years or so. It likely only ever appeared to absorb more UV light and synthesize vitamin D at low sun angles while mostly covered in heavy clothing. Since we can now supplement vitamin D, all the other disadvantages should make it maladaptive.

        • jl6 10 hours ago

          Thousands of years? It’s much more likely that gene editing technology will make skin-color-swaps a routine recreational activity.

      • carapace 11 hours ago

        The primary "pressure" at the moment is to develop species-level self awareness to stabilize the planetary life support system before we crash civilization.

  • sebgr 11 hours ago

    Everytime I see the word delve in an article I can't help but assume it was written by an LLM which this probably was?

    • haswell 11 hours ago

      There were some viral threads going around for a bit that were focused on this word. It never made sense to me - presumably an LLM that outputs the word delve does so because it learned it from the data it was trained on, meaning delve was already a common word.

      I personally have used the word for many years, and have seen it extensively pre-LLM. To me, it’s only a red flag when someone starts producing content that doesn’t match their prior history of writing with a sudden explosion of vocabulary.

    • kzrdude 11 hours ago

      I think "let's delve into it" is a pretty standard formulation that I see everywhere... And have seen for a long time?

    • zeknife 11 hours ago

      I like to think I have a pretty sharp eye for LLM output, and nothing else in the article raised any alarms for me.

    • camus_absurd 11 hours ago

      Maybe it is a regional thing like soda, pop, coke etc

  • yard2010 10 hours 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

  • shermantanktop 12 hours ago

    As usual, popular science coverage always casts evolution as an active process, and sometimes even an intentional process. But anyone who took high school science would recognize the form of evolution in the article as just a result of some people dying early while everyone else went about their business.

    • taeric 11 hours ago

      I'm not clear on what you mean. The definitive example of evolution that I was taught in school was https://en.wikipedia.org/wiki/Peppered_moth_evolution, which is easily described as you just stated it.

      • shermantanktop 7 hours ago

        Right. And if I were a pop-sci writer, my article about it would probably get a headline like "Moths hid in soot by getting darker." Moths didn't do anything, there was no intention.

        We are addicted to stories with protagonists, heroes and villains, and so that's how these stories are framed. But that's the exact opposite of what is happening, and everyone knows it, but apparently we just accept it as inevitable.

        • taeric 6 hours ago

          But that is ignoring what happened. Moths didn't "get darker." Darker moths died at a lower rate than lighter moths did. That is it. That is the mechanism. Similarly, when being darker became less beneficial, they started dying at higher rates again.

          You could reword it to say that "moths that were more hidden in soot were more likely to survive." But that doesn't change anything? The individual moths involved had no intention. They did not choose to favor genetics that give them a darker look.

      • yard2010 11 hours ago

        Not GP. This is not evolution, every human is like a lottery ticket, it doesn't change once you draw it. The system "evolves", not humans. Every human is merely a data point (a vector if you will) in this simulation.

        • taeric 11 hours ago

          What? I am almost with you in that you are not going to individually evolve, necessarily. Colloquial use of the word notwithstanding, of course.

          But you can absolutely see evolution across generations of any animal. Humans included.

    • digging 11 hours ago

      > some people dying early while everyone else went about their business

      So, evolution - just framed correctly.

    • reportgunner 12 hours ago

      I knew enough when the article was explaining what a hemoglobin is.

    • trueismywork 12 hours ago

      That's also evolution.

  • photochemsyn 11 hours 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

    > "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.

  • acadapter 11 hours ago

    Another interesting aspect of modern human evolution is the fact that brave men have a higher risk of dying in war, extreme sports, etc.

    Will male risk behavior be more similar to female risk behavior, 10000 years from now?

    Nowadays, the use-case for masculine bravery is more or less obsolete. It had a purpose when there were wild animals roaming around human habitations, but nowadays it may very well trick a man into becoming a war casualty.

    Historians of the future might look back on pro-conscription advocates as those who stood in the way of the modern human.

    • aliasxneo 11 hours ago

      > masculine bravery

      It sounds like you're using a relatively loose definition here. Masculine bravery is not constrained to only the physical realm.

    • tux1968 11 hours ago

      You're discounting the idea that being a brave man still has any reproductive advantage. I doubt very much that a fearful man is as attractive to women as a brave man, even in modern times.

      • acadapter 11 hours ago

        But there are nuances to that.

        I know several people who have escaped a war-torn country and had a successful life elsewhere, instead of getting affected by military propaganda, and possibly losing everything just because of other people's territorial conflicts.

      • acdha 11 hours ago

        That’s a pretty binary way to describe a spectrum of behavior. The stereotypical sniveling coward, sure, he’s probably not going on a lot of dates but what about someone who’s prudent or careful about the risks they take?

        One especially big confound here is remembering the distinction between having sex and having children. From an evolutionary standpoint, the latter is the only thing which matters and unlike animals humans have contraception which completely changes the situation. From an evolutionary perspective the stereotypical bad boy who’s sleeping around constantly might not have even as many children as the cautious, financially stable guy who is monogamous because the former guy’s partners are looking for fun while the latter’s is intentionally trying to start a family.

      • Y_Y 11 hours ago

        > remember that we are not descended from fearful men

        Edward R. Murrow

        • acadapter 11 hours ago

          We are also not descendants of the 18 year old who eagerly followed a leader and died in a trench.

          What is it with people nowadays, can't there be at least some room for touching this type of sensitive topic?

          My post seems to become a downvote magnet. I just wanted to try an unusual perspective that is seldom talked about.

          • Y_Y 10 hours ago

            Fwiw I upvoted you. To be fair to Murrow he's talking about not being afraid to resist McCarthyism.

            As for general jingoistic propaganda, it's as old as time. I'd also consider it immoral and irrational. Interesting though, as it benefits societies and not (fighting) individuals, and so should have a complex evolutionary dynamics (maybe like with worker bees). _Dulce et decorum est pro patria mori_.

    • solardev 11 hours ago

      Gotta wonder what happens if aggression is bred out of the population genetics, then the aliens/AI/lost tribes/more isolated countries attack.

      As the world moves back to increased nationalism, some cultures are increasingly militaristic while others become keyboard warriors. Over evolutionary time, that could create different enough human subspecies? Maybe we'll see Klingons after all.

    • dominicrose 11 hours ago

      evolution in humans is about who survives, right? more specifically about who survives before having children who themselves survive with or without their parents

      being brave may still be a quality if it's paired with other qualities

      10k years is a lot, try predicting what happens in 10 years..

      • solardev 11 hours ago

        Cultural influences matter a lot too. Even if the parents past down certain genes, a lot of that can be suppressed by environmental or cultural factors, everything from lifestyle to propaganda.

    • scotty79 11 hours ago

      I believe that last half of a century of relative peace in the West is the direct result of the "bravest" (whatever that label means here) in two world wars. So that less brave men (and women) could build in peace. Unfortunately the population of brave men mostly recovered and we are ready for the next great war in Europe that will devastate everything.

      • solardev 11 hours ago

        It's different when you're randomly drafting conscripts from the overall population though, vs having "brave" genes self-select into mortal combat before they can reproduce.

        • scotty79 8 hours ago

          There is no pure randomness in draft. People who know better are more likely to dodge it than "brave" people. Especially if the you draft significant percentage of men. You'll find out that nearly all that managed to avoid the draft are not "brave".