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Humans haven't stopped evolving

83 points by ilamont 3mo ago

ktwee 3mo ago
NLP
lomlobon 3mo ago
Isn't this obvious? Why on earth would it stop? I don't actually believe that 'humans stopped evolving' was ever a widespread belief among scientists. This article has gotta be lying to me.
- remarkEon 3mo ago
  Perhaps it was not a widespread belief among scientists, I don't know, but if you were to posit in front of polite company that humans are today and always have been under evolutionary pressures that select for certain traits you would have gotten some odd looks. The implications are possibly a little uncomfortable, especially if what this article suggests is true and the pace of evolution is accelerating.
- derektank 3mo ago
  I have definitely run into the belief that humans aren’t evolving anymore (though not among scientists). I think people with an incomplete understanding of evolution look around, see most human beings survive to adulthood, and assume that there must be no more evolutionary pressures on us (perhaps with the phrase “survival of the fittest” tinging around inside their head). I honestly don’t blame anyone who hasn’t been exposed to the concept of e.g. sexual selection for making the assumption.
  - delichon 3mo ago
    There's been no biological change in humans in 40,000 or 50,000 years. Everything we call culture and civilization we’ve built with the same body and brain. -- Stephen Jay Gould, "The Spice of Life", 2000 Gould was an evolutionary biologist and Harvard professor, and one of the most prominent popularizers of evolution since Darwin, but somehow believed that it doesn't apply to modern humans.
    - remarkEon 3mo ago
      That's such an extreme claim. It defies common sense. You'd have to proclaim that there was some event that _stopped_ evolution in humans, universally. How is that even possible? Especially 50k years ago. I'd be a little more forgiving if the claim was that evolution stopped in, say, 1999.
      - RajT88 3mo ago
        Rather a lot more things about human genomic history are known today compared to 2000. Discoveries about being able to process lactose and when those genes evolved all were after 2000, for example. Does it excuse Gould for making such bold claims? You have to decide I guess. That is a lot fuzzier.
        remarkEon 3mo ago
        I guess I would need to read more of what Gould wrote. For example, did he claim that evolution in other species also stopped?
        margalabargala 3mo ago
        I think the claim that humans stopped evolving is an uncharitable reading. Another would be, 50k years is such a narrow window that evolution cannot be observed across it.
        t0mpr1c3 3mo ago
        It's not an uncharitable reading if Gould stated his claim unequivocably. Your alternative claim is just factually wrong. The population frequency of an allele under selection pressure can change within a few generations. For example the HbS allele, that confers both sickle cell trait and malaria resistance, became less common among Africans transported as slaves to regions where malaria was not endemic.
        asdff 3mo ago
  - knowaveragejoe 3mo ago
    For the average person considering this question it also goes without saying that it's hard to grasp the time scales involved.
- adrianN 3mo ago
  There are a couple of species that remain essentially unchanged for the last couple million years. Why can't humans become one of them?
  - jl6 3mo ago
    Good question, with a couple of possible answers: 1) maybe those species aren’t as unchanged as we think, because our evidence of the past is limited to things like skeletons, and maybe the skeletal structure of the shark didn’t change much, but other aspects did. But more likely… 2) maybe unchanging requires a stable environment with stable selection pressures - but humans have had a rollercoaster of change in selection pressures, possibly more than any other species.
  - asdff 3mo ago
    Nothing stops mutating. What you see with those species is that they found a zone of stability in the fitness landscape, a local optimum. They still have mutants, you just don't see them outcompeting and shifting the makeup of the overall population as the dominant form is already the most fit. Now consider our own species and the pressures that got us to this present body plan. They just aren't there. The shark still is facing pressures that favor the hundreds of millions of years old shark morphology. Are we facing pressures that our hominid ancestors faced? Doubtful. Look at how our bodies often react when they meet the pressures of our modern society: we often become anxious, depressed, and obese. Most of our ill behaviors such as this have some survival advantage to it that just isn't getting pressured in modern society. Your constant anxiety keeping you up at night is actually saving your family clan from a lurking predator in the bush. Your lack of portion control abilities means you can eat all the fish you just caught and pack on more fat to your frame to smooth over leaner times. Today these selective advantages are seen as illnesses people see doctors to get pills for. Our bodies are so misplaced for the society we've built for ourselves. Our mind's can't even fully fit this society into a working model ourselves without missing a lot of important information. We've out ran our capabilities a long time ago in some senses with the cultural/technological evolution that overshot our own biology. We are tumbling into some new body plan I'm not sure what exactly, but things aren't in any way stable now.
  - HarHarVeryFunny 3mo ago
- HarHarVeryFunny 3mo ago
  Yeah, seems like either a clickbait title, or maybe they believe their readership is so misinformed as to believe that human evolution could and has stopped. I'd not be surprised if, especially in the US, a large percentage of the public does actually believe this.
  - nobody9999 3mo ago
    >Yeah, seems like either a clickbait title, or maybe they believe their readership is so misinformed as to believe that human evolution could and has stopped. I'd not be surprised if, especially in the US, a large percentage of the public does actually believe this. When the belief is that of "creationism"[0], it's not so far to go to reject evidence of, well, anything that runs counter to the narrative espoused by a variety of those belief systems. Including the fact of evolution. I'd point out that those who subscribe to such belief systems are a large fraction of the human population, the largest contingent of which are not resident in the United States, nor are they Americans. And perhaps those who create such titles are cynically exploiting the gullible. Then again, I'd posit that Hanlon's Razor[1] be assessed in this case. Such an assessment might well uncover cynicism/evil, but probably not -- as those involved may well subscribe to the belief systems referenced above and/or are ignorant/dumb. All that said, such an idea isn't new. Here's an analog[0] from more than 400 years ago (circa 1600AD): What a piece of work is a man, How noble in reason, how infinite in faculty, In form and moving how express and admirable, In action how like an Angel, In apprehension how like a god, The beauty of the world, The paragon of animals [0] https://en.wikipedia.org/wiki/What_a_piece_of_work_is_a_man https://en.wikipedia.org/wiki/What_a_piece_of_work_is_a_man [1] https://en.wikipedia.org/wiki/Hanlon%27s_razor https://en.wikipedia.org/wiki/Hanlon%27s_razor
    - HarHarVeryFunny 3mo ago
      Sure the US only comprises 5% of the global population, so insignificant in terms of global thought trends. I only mentioned the US since this is an American magazine and the title is probably chosen to appeal to an assumed mostly American readership. I was referring to scientific illiteracy/denial rather than creationists (who don't believe we're the product of evolution in the first place). I don't think Hanlon's Razor applies here. The author of a Harvard Magazine article is unlikely to be stupid, especially given the article in question, nor can choosing a clickbait title be considered as "malice". One can wonder what was the exact thought process in coming up with the title - perhaps more charitably they just thought that many people might think that human evolution is slowing, if not actually stopped, or maybe there really wasn't much thought put into it at all !
serious_angel 3mo ago
The choice for the illustration is marvelous, no words... I love it... Thank you for mentioning the Artists of so ineffably magnificent works: - https://luisajung.com/ https://luisajung.com/
fhn 3mo ago
Genetic drift is not evolution. Every single birth brings about genetic drift. Evolution is gaining or losing specific traits. Individually, humans do gain and lose traits but from an macroscopic view, those traits are just a blip. An cheetah that lose it's ability to run fast many not survive. A human that loses a some useful trait does not die(government assistance. I'm talking about the West because I can't speak for every place in the world) and might even pass that trait down the line. An cheetah that gains the ability to run even faster thrives, outcompete competitors, and most likely pass on this trait. A human that gains a useful trait(faster, stronger, better vision, better hearing) does not amount to much;, might win competitions and make a bunch of money but many people can make a bunch of money without that trait so it's nothing really special. Overall, it's a wash because in one generation, you might have some good genes and the next generation, no so good genes. Therefore, no evolution.
- hn_throwaway_99 3mo ago
  This is certainly not what I learned to be the definition of evolution in my biology classes. First, the article is not just proposing genetic drift, which is the change in allele frequency by chance. It is arguing that change in allele frequency is due to natural selection pressure, and that most certainly is evolution. Copied from the Wikipedia entry, because I think it's simple and clear: > Evolution is the change in the heritable characteristics of biological populations over successive generations. It occurs when evolutionary processes such as genetic drift and natural selection act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. That is exactly what the article described.
  - rendaw 3mo ago
    The article is talking about the last 5000 years, GP is talking about the last 50-100 years. I think most people who say that natural selection is over are talking about ~100 years and not 5000 years.
    - remarkEon 3mo ago
prologic 3mo ago
If that's true. Why haven't we evolved into a species that doesn't harm each other or the environment?
- mhurron 3mo ago
  Because we became an incredibly successful species doing just that.
  - HarHarVeryFunny 3mo ago
    On an evolutionary timescale it's a bit early to call humans a success. We only diverged from other apes about 5 million years ago, and have existed in modern human form for much less. Mitochondrial Eve lived only 100-200K years ago. In the last few hundred years since industrialization we've been destroying our own environment - the one we'd previously adapted to - at a rather remarkable rate, an "experiment" that is still playing out. Will it turn out to be successful, or will we end up modifying the environment so much (or just fail to evolve quickly enough to adapt to changes outside of our control) that in another million years we'll all be gone? We'll certainly not last forever, even if we manage to have a run as long as the dinosaurs. Whether it's climate change, disease, or some unforeseen change in our fortunes, eventually we'll either go extinct or branch off into a bunch of other species that would be unrecognizable to ourselves.
- deepsun 3mo ago
  Wars did become less violent, but the on scales of several hundreds of years. I'm not talking about industrializing death, but about desire of violence (civilian suffering, genocide). Evolution is very slow.
- danwills 3mo ago
  I think that that might be an aspect of the reproductive fitness of the 'hive' (or meta-organism) of all humans, rather than the genes in any individual or population. I agree individual humans mostly seem to behave more like single-celled micro-organisms and it's a stretch to call it a collective-organism, but it's also not impossible to see the relevant analogous aspects though I think! (like, the internet could be one example?) It's an interesting question whether the human species (or life-as-a-whole?) viewed as a single-system will be able to reproduce itself. Sounds like the question only makes sense when talking about settling elsewhere than Earth.. Mmm, reminds me of the Fermi Paradox. Will we make it through this!?!
vikramkr 3mo ago
The idea that humans have undergone high selective pressure for genes related to immunity in some way during a recent 5000 year period in which massive urbanization lead to a truly unfathomable amount of deaths including staggering percentages of humans dying in childhood because of various infectious diseases, plagues, pandemics, etc, and that those changes involved large numbers of small changes across a large number of genes in complex regulatory networks, is probably the least surprising discovery in the history of the universe. It's good science and it's obviously important research to do, not in the least because it can shed light on evolutionary pressures that may be driving the rise in autoimmune diseases we see in the modern day, but the framing of the PR slop article around it is truly so stupid. Maybe if it found selective pressures were still dominating and driving evolution in recent decades in developed nations with low childhood mortality that would be surprising. Though the framing of the article is almost that it would be surprising if mutations were happening at all which is obviously stupid - we haven't figured out how to reverse entropy so mutation rates haven't gone down, evolution by genetic drift is obviously continuing to occur, and with advances in medicine the number of folks surviving with mutations that would have been problematic otherwise is increasing. Truly disappointing slop. Like obviously humans faced selective pressures during an era when like 8 in 10 kids died of plague or similar things, a biological factor where survival is correlated with genetic factors that influence immunity and disease survival. Again, super useful science to see exactly what that influence was, but it would only be surprising if we learned we'd somehow managed to turn off entropy and statistics during the black death and we didn't face selective pressures.
danwills 3mo ago
I'm reminded of this section of a Douglas Adams quote: "Anything that, in happening, causes itself to happen again, happens again." I like how this is not even specific to life nor genes, and it's not hard to add to it the idea of happening-again in ways that make the thing better-or-worse at happening again. Personally I think this applies to all coherently-causal systems.. still trying to figure out whether to believe QM is fully causal or not! (Currently seems like it might be a mixture?)
stevenalowe 3mo ago
sure seems like a lot of 'em have
- dang 3mo ago
  Maybe so, but can you please not post unsubstantive comments to Hacker News? We're trying for something a bit different here.
  - stevenalowe 3mo ago
    dang, sorry
bebe83949rj 3mo ago
[flagged]
- nozzlegear 3mo ago
  Humans are the only mammals with genders at all. Are you confusing gender with sex?
  - deleted 3mo ago
    [deleted]
  - bebe83949rj 3mo ago
    Both are synonyms! Like when pretend "woman" sports are not for woman, but "female" only! Or woman should be in mans only prison, to get raped!
    - nozzlegear 3mo ago
      > Both are synonyms! Not the way you're using them. Dogs and cats don't have genders, but they do have sexes.
  - inigyou 3mo ago
    Has that been proven?
    - nozzlegear 3mo ago
      There are some animals that come close to having what we'd call gender roles: bonobos, some other primates (not all), and a bird called a ruff. But as far as we can tell, those animals don't have an internal "I am X gender" self concept. (Interesting note: bonobos are very fluid and change their gender roles depending on the situation and context.)
      - inigyou 3mo ago
        We can't talk to them, so we don't know how they feel, so of course they don't have any known internal feelings. If you observed humans from a distance in their natural habitat for a while you probably also wouldn't find any gender.
hn_throwaway_99 3mo ago
Given that fertility rates are currently plummeting worldwide, the principles of natural selection would dictate that humans are currently undergoing very high selection pressure for specific traits. Basically, any genetic trait that causes people today to think "You know, I think I'm going to remain childfree" is specifically selected against, and any trait that causes people to want more children will be selected for. I'd argue that the invention of reliable birth control was that biggest change in human selective pressures in history. Evolution made sex highly pleasurable and desirable because it often resulted in passing on your genes. That's no longer true with reliable birth control, and with such a huge environmental shift natural selection will act on other avenues that cause people to have children.
- gblargg 3mo ago
  [flagged]
  - chmod775 3mo ago
    One reason our ancestors had plenty of children is that children were a large net-benefit to them. Many modern societies are structured in a way that makes children an economic negative to their parents. From an individuals' POV, the "smart" play is not having children and hope others do. Individuals believe that they do not need children because they have saved up for retirement, not accounting for the fact that if everyone did this and there was nobody left to do any work once they reach retirement age, that money will be worthless and they'll be unable to retire. The alternative is mass-scale immigration, and that's becoming unpopular. For an example of what happens if a society has neither enough children, nor immigration, see South Korea. Poverty among the elderly is rampant and they are increasingly being forced back into the labor market. Many western societies needed to start applying a large multiplier to parental benefits decades ago.
  - derektank 3mo ago
    >People aren't born not wanting to have kids, since all their ancestors did. What evidence do you have that all their ancestors wanted to have kids? I can think of a lot of reasons why people may have had kids without necessarily wanting them. They wanted to have sex in an era before birth control. They were pressured into it by the social norms of their local community. They were raped. Etc. I have a lot of criticism of the childfree movement but I think it’s pretty disrespectful to assume they’re not being honest when they say they don’t want to have kids and that they’ve always felt that way.
deepsun 3mo ago
As far as I was taught in college, evolution never stops, but we're just too short lived to notice that. We _may_ notice some very tiny blip on timescales of several hundred years, but last really noticeable traits happened many thousands years ago. However, cultural/society/educational evolution happens much-much faster (but is also much-much weaker, can disappear on just a few weeks).
- Grimblewald 3mo ago
  also, technology largly exists to remove the discomfort of evolutionary pressure. This doesnt mean the mutations that give rise to evolutionary changes in the population, but it does mean we've removed or mititaged many of the mechanisms which would select for specific traits. Again, we would naturally still change, but not in the the way or at the rate otger organisms continue to or at which we would sans technology.
  - plastic-enjoyer 3mo ago
    > also, technology largly exists to remove the discomfort of evolutionary pressure. I think this is a very limited way to view technology
    - Grimblewald 3mo ago
      sure, it can be. However, I'd argue in a large amount of cases it fits. Agriculture, medicine, transport combine massivly lower the bar for base survival let alone reproduction on all skill checks otgerwise place don metabolism, physical fitness, immunological fitness. This isnt me taking a dig either, I am among the ranks of those who would be dead without these modern "comforts" but as a reuslt if there is a genetic driver for my lack of fitness (which there is) those genes are now not being selected against. Perhaps we don't think of tech as an evolution stop, but really most of the comfort and conveniance it brings are won by removing the discomfort otherwise applied as evolutionary pressure. Can't live in this place? no worries, create air conditioning. Can't calculate this? no worries, computers. Can't feed all these mouths because hunting and gathering wouldnt work? no worries, agriculture. Tech, in my opinion, offers most of its perceived benefits by removing natural pressures to move, stop, or adapt from ourselves.
jona-f 3mo ago
Who said we stopped evolving? Evolution is slow cause we are many. Another garbage clickbait press release that butchers the science.
_moof 3mo ago
I can't find the source now but an idea that really stuck with me is that evolution happens on the margins. If a 0.0001% increase in the height of a giraffe makes it 0.0001% more likely that the giraffe will survive and reproduce, then in 1 million years giraffes as a species will become taller. As for humans: I mean, duh? The selective pressures faced by humans have changed radically in the time we've been around.
deleted 3mo ago
[deleted]
jiggawatts 3mo ago
It is well established that evolution is driven not only by fitness in the trivial sense of "survival or death", but in large part by mate selection. (Disclaimer: The rest is a personal theory with zero scientific support.) This begs the question: selection based on what? In many bird species it is the complexity of the male's song, or the colourful beauty of his feathers. There are "dances" and courtship rituals in many animals, including even insects. Humans almost certainly also subject to evolution caused by the evolutionary pressures of mate selection! This is best said by Anthony Hokpins in Westworld: https://www.youtube.com/watch?v=OjsGJOXhPGU https://www.youtube.com/watch?v=OjsGJOXhPGU "I read a theory once that the human intellect was like peacock feathers. Just an extravagant display intended to attract a mate. All of art, literature, a bit of Mozart, William Shakespeare, Michelangelo, and the Empire State Building—just an elaborate mating ritual. Maybe it doesn't matter that we have accomplished so much for the basest of reasons. But, of course, the peacock can barely fly. It lives in the dirt, pecking insects out of the muck, consoling itself with its great beauty." Which is a good bit of drama, but... if true, what are the consequences for the evolution of the human species? Assume for a moment, that yes, women are attracted to male intelligence, which men show off with music, art, and "great works". The obvious immediate effect is that this causes the average intelligence of Homo Sapiens to increase over time. But the secondary effect is more interesting: judging intelligence benefits from more intelligence! As the next generation of women inherit greater intelligence, they become better judges of male intelligence, more picky and precise. This forces male intelligence to increase ever faster to keep up with the "rising demand". Rinse and repeat. I can't prove, but strongly suspect that this is the case. Birds of Paradise become "more beautiful" on the scale of aeons because more beauty in the males doesn't improve the judgement of the females. Humans become more intelligent on the scale of mere millenia because more intelligence does improve the judgement of the females.
- Terr_ 3mo ago
  > > just an elaborate mating ritual. You might find the book Blindsight interesting, since... Well, to avoid spoilers, I'll just say the story doesn't put our concept of intelligence on the usual top-of-creation pedestal.
  - 3mo ago
keeda 3mo ago
Am I the only one who thought that was a given based on phenomena like this: https://www.nationalgeographic.com/science/article/bajau-sea-nomads-free-diving-spleen-science https://www.nationalgeographic.com/science/article/bajau-sea... we all are not quite freediving most of our waking lives, but the daily pressures of modern urban living must be exerting a similar level of evolutionary pressure on us.
chr15m 3mo ago
Lactose tolerance is a classic example of a recently evolved trait. https://en.wikipedia.org/wiki/Lactase_persistence https://en.wikipedia.org/wiki/Lactase_persistence
- saidnooneever 3mo ago
  I for one am glad that now people can have a healthy serving of cheese without the side effects. Do you think we will become more and more tolerant? like with the happy people? One day maybe we can drink only milk and eat only cheese, even on the sweltering summer heat. For me those days i still struggle and sometimes reluctantly find myself reverting back to greens
  - serious_angel 3mo ago
    > Do you think we will become more and more tolerant? I do not, sorry. This question feels quite odd to see, too, frankly. I became intolerant in ~20 years just "because", and only when I checked at medics for non-related general tests, and out of the blue it showed on the results paper. And And this is when I never had any abnormal meals with it, but just casually and normally as any other one, I believe. It was like a blow to the gut... This intolerance changes the life much. It makes impossible to have any meals with other people in group or be afraid of trying anything that may have any kind of milk in it, and you may imagine that there's so much of it out there... including many kinds of common bread, cakes, candies, certain cheese, coffee as Latte, Cappuccino etc. The aftereffect depends on the person, and some have diarrhea-type issues, but in the case here, it only the stomach that hurts so much as if someone cuts it inside-out. There are tablets, but... it's always dear scary and it doesn't help much... Currently, I am ~1.75m and ~63kg in ~40 years old woman, and I see more of this intolerance become normalized in European and Asian countries where some stores sell lactose-free holy milk and some cafes offer a so much appreciated lactoze-free lovely coffee...
    - jareklupinski 3mo ago
      lactaid
cubefox 3mo ago
The most terrifying evolutionary trend is that nowadays fertility is negatively correlated with intelligence. That is, there is a strong selective pressure for humans to become dumber.
- HarHarVeryFunny 3mo ago
  Maybe AI will fix this. We'll all be out of work, surviving off our own wits, and ability to survive and thrive will go back to being based on things we judge as desirable.
  - cubefox 3mo ago
    I don't see how this would fix IQ decline.
    - HarHarVeryFunny 3mo ago
      I'm half joking, but what I meant was that self-sufficiency seems to be more demanding than many jobs, so success might be more dependent on characteristics that used to be more important in the past, and got us to where we are today. On reconsideration, it's not clear how much of our increase in intelligence over the last few million years is due to the greater success of more intelligent individuals, or rather the greater success of more collectively intelligent populations, based on language and communication etc. Again, half-joking, but it's interesting to consider if AI as an "intelligence leveler" could eventually have an effect. If we all have access to super-intelligence, then does our own individual intelligence matter that much? You could even speculate that the invention of AI puts a cap on the intelligence of a species since then perhaps the success of the species depends more on the intelligence of the AI, not of the species itself.
      - cubefox 3mo ago
        I think our intelligence is crucial to make sure that we won't get replaced by AI.
metalman 3mo ago
the problem is that humans are modifying the environment, orders of magnitude faster than evolution can keep up with, and many of the "features" of our modern technological cities are prouncedly geared towards our worst/best (non) survival instincts, as from an evolutionary perspective we are all living in the valley of infinite plentitude, and survival of the fittest has taken on an entirely other definition.
- inigyou 3mo ago
  Evolution doesn't find a solution to a problem. Instead, it finds all possible solutions. Ones which don't fit through the problem are culled. During happy times, mutation creates a variety of individuals. During stressful times, individuals who happen to have traits that help them weather the stress are the ones who survive more. Sometimes much more. That's when the evolution happens. Both parts can happen concurrently and gradually, like those butterflies who turned black to hide in coal smoke.
  - lotsofpulp 3mo ago
    >Both parts can happen concurrently and gradually, like those butterflies who turned black to hide in coal smoke. Do you mean the black ones survived and procreated?
    - inigyou 3mo ago
      Yes, but gradually. The blacker ones reproduced more. There weren't any black ones at the beginning The opposite is the Black Death. Some people had more aggressive immune systems that were able to destroy the bacteria before it destroyed them. This is thought to have caused a jump increase in the "immune aggressivity" of European populations, causing more autoimmune diseases in subsequent generations.
chaz6 3mo ago
Does anybody think that evolution just stops? A species only stops evolving when it is wiped out.
- vitally3643 3mo ago
  Or when they develop a society which removes all evolutionary pressures. Evolution isn't magical, it's purely probabilistic. You can drive the probabilities down real low and then genetically engineer the rest away.
  - HarHarVeryFunny 3mo ago
    As long as all offspring aren't 100% exact clones of the parents then you'll get evolution. In practical terms it would be impossible to genetically engineer away genetic variation (assuming you could convince people to stop having sex and visit your cloning lab instead). There are all sorts of things like DNA damage, horizontal gene transfer, and just the inherent error potential of reproduction that you would never be able to eliminate. Of course it would also be highly undesirable to stop genetic variation, since that's what gives a species the ability to adapt and survive.
    - seanmcdirmid 3mo ago
      You’ll get mutations, not evolution. You still need natural selection to sort out the mutations which gives us evolution, and that’s a bit harder now that we don’t have to worry about being hunted down by tigers. Anyone can reproduce and pass down their genes, so what mutations are we currently selecting? Maybe looks, but I doubt even that.
      - saltcured 3mo ago
        You're saying that as if survival doesn't remain an evolutionary pressure. Life is inherently demanding, and many mutations are lethal. So, at best, the argument seems to be that the surviving gene pool may get more complex with lots of optional mutations which all coexist? Could we end up like some plant species full of cultivars where larger swathes of genes are expressing differently out of a very convoluted library? If you're envisioning medical science to allow people to survive with otherwise lethal mutations, I would say that is not an escape from evolution. Instead, you've revised the reproductive cycle to include more epigenetic components. The species is still the survivable set of genes and cultural practices which are evolving together, and which terminate when they no longer function as a system.
gweinberg 3mo ago
"Most research during the past two decades hinted that human evolution has largely slowed or changed so subtly that existing tools couldn’t detect it; evidence seemed to suggest that civilization put humans beyond the reach of natural selection." There has never been the slightest shred of evidence to that effect, anywhere, ever.
- ASalazarMX 3mo ago
  It's logical. Survival of the fittest was initially driven by the environment; then we formed civilizations, and culture influenced what "fittest" was. Now we have technology that defines the "fittest" further. The urban fittest of the future could end up being people succesful enough to pay for advanced medicine. Evolution still happens when creatures reproduce at different ratios, but civilization and tech allows people to survive and/or reproduce when they naturally wouldn't.
  - vinceguidry 3mo ago
    I love it. Claim gets made, it's pointed out that there's no evidence for said claim, claim gets justified anyway with some version of "it's logical / rational / stands to reason." All it amounts to is 'sounds good to me'.
    - ASalazarMX 3mo ago
      It doesn't just "sound good to me", you can watch culture and technology influence reproduction, the main driving force of evolution. For example, today we can sit for hours and thrive, while a hunter-gatherer or farmer would starve sitting around all day. Our bodies protest, but we manage to reproduce, and treat or palliate the ailments that come with sedentarism. We surely are evolving to better tolerate sedentarism, but it's slowed down because medicine allow the unfit to sedentarism to survive and reproduce instead of dying early. You can see the delay of evolution, allowing the biologically unfit to reproduce, at any hospital. Medicine saves or prolongs more lives than ever, and death is the second driving force of evolution. Stephen Hawkins, for example, was diagnosed with ALS and given two years to live, and despite that he had three descendants years after. He couldn't do physical work, but could do great mental work, which our society values. You can correctly argue that our civilization is part of the environment, though. In that case, natural evolution isn't slowing down, it's just going in a different direction than it used to.

83 points by ilamont 3mo ago

ktwee 3mo ago

NLP

Isn't this obvious? Why on earth would it stop? I don't actually believe that 'humans stopped evolving' was ever a widespread belief among scientists. This article has gotta be lying to me.

remarkEon 3mo ago
Perhaps it was not a widespread belief among scientists, I don't know, but if you were to posit in front of polite company that humans are today and always have been under evolutionary pressures that select for certain traits you would have gotten some odd looks. The implications are possibly a little uncomfortable, especially if what this article suggests is true and the pace of evolution is accelerating.
derektank 3mo ago
I have definitely run into the belief that humans aren’t evolving anymore (though not among scientists). I think people with an incomplete understanding of evolution look around, see most human beings survive to adulthood, and assume that there must be no more evolutionary pressures on us (perhaps with the phrase “survival of the fittest” tinging around inside their head). I honestly don’t blame anyone who hasn’t been exposed to the concept of e.g. sexual selection for making the assumption.
- delichon 3mo ago
  There's been no biological change in humans in 40,000 or 50,000 years. Everything we call culture and civilization we’ve built with the same body and brain. -- Stephen Jay Gould, "The Spice of Life", 2000 Gould was an evolutionary biologist and Harvard professor, and one of the most prominent popularizers of evolution since Darwin, but somehow believed that it doesn't apply to modern humans.
  - remarkEon 3mo ago
    That's such an extreme claim. It defies common sense. You'd have to proclaim that there was some event that _stopped_ evolution in humans, universally. How is that even possible? Especially 50k years ago. I'd be a little more forgiving if the claim was that evolution stopped in, say, 1999.
    - RajT88 3mo ago
      Rather a lot more things about human genomic history are known today compared to 2000. Discoveries about being able to process lactose and when those genes evolved all were after 2000, for example. Does it excuse Gould for making such bold claims? You have to decide I guess. That is a lot fuzzier.
      - remarkEon 3mo ago
        I guess I would need to read more of what Gould wrote. For example, did he claim that evolution in other species also stopped?
        margalabargala 3mo ago
        I think the claim that humans stopped evolving is an uncharitable reading. Another would be, 50k years is such a narrow window that evolution cannot be observed across it.
        t0mpr1c3 3mo ago
        It's not an uncharitable reading if Gould stated his claim unequivocably. Your alternative claim is just factually wrong. The population frequency of an allele under selection pressure can change within a few generations. For example the HbS allele, that confers both sickle cell trait and malaria resistance, became less common among Africans transported as slaves to regions where malaria was not endemic.
        asdff 3mo ago
- knowaveragejoe 3mo ago
  For the average person considering this question it also goes without saying that it's hard to grasp the time scales involved.
adrianN 3mo ago
There are a couple of species that remain essentially unchanged for the last couple million years. Why can't humans become one of them?
- jl6 3mo ago
  Good question, with a couple of possible answers: 1) maybe those species aren’t as unchanged as we think, because our evidence of the past is limited to things like skeletons, and maybe the skeletal structure of the shark didn’t change much, but other aspects did. But more likely… 2) maybe unchanging requires a stable environment with stable selection pressures - but humans have had a rollercoaster of change in selection pressures, possibly more than any other species.
- asdff 3mo ago
  Nothing stops mutating. What you see with those species is that they found a zone of stability in the fitness landscape, a local optimum. They still have mutants, you just don't see them outcompeting and shifting the makeup of the overall population as the dominant form is already the most fit. Now consider our own species and the pressures that got us to this present body plan. They just aren't there. The shark still is facing pressures that favor the hundreds of millions of years old shark morphology. Are we facing pressures that our hominid ancestors faced? Doubtful. Look at how our bodies often react when they meet the pressures of our modern society: we often become anxious, depressed, and obese. Most of our ill behaviors such as this have some survival advantage to it that just isn't getting pressured in modern society. Your constant anxiety keeping you up at night is actually saving your family clan from a lurking predator in the bush. Your lack of portion control abilities means you can eat all the fish you just caught and pack on more fat to your frame to smooth over leaner times. Today these selective advantages are seen as illnesses people see doctors to get pills for. Our bodies are so misplaced for the society we've built for ourselves. Our mind's can't even fully fit this society into a working model ourselves without missing a lot of important information. We've out ran our capabilities a long time ago in some senses with the cultural/technological evolution that overshot our own biology. We are tumbling into some new body plan I'm not sure what exactly, but things aren't in any way stable now.
- HarHarVeryFunny 3mo ago
HarHarVeryFunny 3mo ago
Yeah, seems like either a clickbait title, or maybe they believe their readership is so misinformed as to believe that human evolution could and has stopped. I'd not be surprised if, especially in the US, a large percentage of the public does actually believe this.
- nobody9999 3mo ago
  >Yeah, seems like either a clickbait title, or maybe they believe their readership is so misinformed as to believe that human evolution could and has stopped. I'd not be surprised if, especially in the US, a large percentage of the public does actually believe this. When the belief is that of "creationism"[0], it's not so far to go to reject evidence of, well, anything that runs counter to the narrative espoused by a variety of those belief systems. Including the fact of evolution. I'd point out that those who subscribe to such belief systems are a large fraction of the human population, the largest contingent of which are not resident in the United States, nor are they Americans. And perhaps those who create such titles are cynically exploiting the gullible. Then again, I'd posit that Hanlon's Razor[1] be assessed in this case. Such an assessment might well uncover cynicism/evil, but probably not -- as those involved may well subscribe to the belief systems referenced above and/or are ignorant/dumb. All that said, such an idea isn't new. Here's an analog[0] from more than 400 years ago (circa 1600AD): What a piece of work is a man, How noble in reason, how infinite in faculty, In form and moving how express and admirable, In action how like an Angel, In apprehension how like a god, The beauty of the world, The paragon of animals [0] https://en.wikipedia.org/wiki/What_a_piece_of_work_is_a_man https://en.wikipedia.org/wiki/What_a_piece_of_work_is_a_man [1] https://en.wikipedia.org/wiki/Hanlon%27s_razor https://en.wikipedia.org/wiki/Hanlon%27s_razor
  - HarHarVeryFunny 3mo ago
    Sure the US only comprises 5% of the global population, so insignificant in terms of global thought trends. I only mentioned the US since this is an American magazine and the title is probably chosen to appeal to an assumed mostly American readership. I was referring to scientific illiteracy/denial rather than creationists (who don't believe we're the product of evolution in the first place). I don't think Hanlon's Razor applies here. The author of a Harvard Magazine article is unlikely to be stupid, especially given the article in question, nor can choosing a clickbait title be considered as "malice". One can wonder what was the exact thought process in coming up with the title - perhaps more charitably they just thought that many people might think that human evolution is slowing, if not actually stopped, or maybe there really wasn't much thought put into it at all !

serious_angel 3mo ago

The choice for the illustration is marvelous, no words... I love it... Thank you for mentioning the Artists of so ineffably magnificent works: - https://luisajung.com/ https://luisajung.com/

fhn 3mo ago

Genetic drift is not evolution. Every single birth brings about genetic drift. Evolution is gaining or losing specific traits. Individually, humans do gain and lose traits but from an macroscopic view, those traits are just a blip. An cheetah that lose it's ability to run fast many not survive. A human that loses a some useful trait does not die(government assistance. I'm talking about the West because I can't speak for every place in the world) and might even pass that trait down the line. An cheetah that gains the ability to run even faster thrives, outcompete competitors, and most likely pass on this trait. A human that gains a useful trait(faster, stronger, better vision, better hearing) does not amount to much;, might win competitions and make a bunch of money but many people can make a bunch of money without that trait so it's nothing really special. Overall, it's a wash because in one generation, you might have some good genes and the next generation, no so good genes. Therefore, no evolution.

hn_throwaway_99 3mo ago
This is certainly not what I learned to be the definition of evolution in my biology classes. First, the article is not just proposing genetic drift, which is the change in allele frequency by chance. It is arguing that change in allele frequency is due to natural selection pressure, and that most certainly is evolution. Copied from the Wikipedia entry, because I think it's simple and clear: > Evolution is the change in the heritable characteristics of biological populations over successive generations. It occurs when evolutionary processes such as genetic drift and natural selection act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. That is exactly what the article described.
- rendaw 3mo ago
  The article is talking about the last 5000 years, GP is talking about the last 50-100 years. I think most people who say that natural selection is over are talking about ~100 years and not 5000 years.
  - remarkEon 3mo ago

prologic 3mo ago

If that's true. Why haven't we evolved into a species that doesn't harm each other or the environment?

mhurron 3mo ago
Because we became an incredibly successful species doing just that.
- HarHarVeryFunny 3mo ago
  On an evolutionary timescale it's a bit early to call humans a success. We only diverged from other apes about 5 million years ago, and have existed in modern human form for much less. Mitochondrial Eve lived only 100-200K years ago. In the last few hundred years since industrialization we've been destroying our own environment - the one we'd previously adapted to - at a rather remarkable rate, an "experiment" that is still playing out. Will it turn out to be successful, or will we end up modifying the environment so much (or just fail to evolve quickly enough to adapt to changes outside of our control) that in another million years we'll all be gone? We'll certainly not last forever, even if we manage to have a run as long as the dinosaurs. Whether it's climate change, disease, or some unforeseen change in our fortunes, eventually we'll either go extinct or branch off into a bunch of other species that would be unrecognizable to ourselves.
deepsun 3mo ago
Wars did become less violent, but the on scales of several hundreds of years. I'm not talking about industrializing death, but about desire of violence (civilian suffering, genocide). Evolution is very slow.
danwills 3mo ago
I think that that might be an aspect of the reproductive fitness of the 'hive' (or meta-organism) of all humans, rather than the genes in any individual or population. I agree individual humans mostly seem to behave more like single-celled micro-organisms and it's a stretch to call it a collective-organism, but it's also not impossible to see the relevant analogous aspects though I think! (like, the internet could be one example?) It's an interesting question whether the human species (or life-as-a-whole?) viewed as a single-system will be able to reproduce itself. Sounds like the question only makes sense when talking about settling elsewhere than Earth.. Mmm, reminds me of the Fermi Paradox. Will we make it through this!?!

vikramkr 3mo ago

The idea that humans have undergone high selective pressure for genes related to immunity in some way during a recent 5000 year period in which massive urbanization lead to a truly unfathomable amount of deaths including staggering percentages of humans dying in childhood because of various infectious diseases, plagues, pandemics, etc, and that those changes involved large numbers of small changes across a large number of genes in complex regulatory networks, is probably the least surprising discovery in the history of the universe. It's good science and it's obviously important research to do, not in the least because it can shed light on evolutionary pressures that may be driving the rise in autoimmune diseases we see in the modern day, but the framing of the PR slop article around it is truly so stupid. Maybe if it found selective pressures were still dominating and driving evolution in recent decades in developed nations with low childhood mortality that would be surprising. Though the framing of the article is almost that it would be surprising if mutations were happening at all which is obviously stupid - we haven't figured out how to reverse entropy so mutation rates haven't gone down, evolution by genetic drift is obviously continuing to occur, and with advances in medicine the number of folks surviving with mutations that would have been problematic otherwise is increasing. Truly disappointing slop. Like obviously humans faced selective pressures during an era when like 8 in 10 kids died of plague or similar things, a biological factor where survival is correlated with genetic factors that influence immunity and disease survival. Again, super useful science to see exactly what that influence was, but it would only be surprising if we learned we'd somehow managed to turn off entropy and statistics during the black death and we didn't face selective pressures.

danwills 3mo ago

I'm reminded of this section of a Douglas Adams quote: "Anything that, in happening, causes itself to happen again, happens again." I like how this is not even specific to life nor genes, and it's not hard to add to it the idea of happening-again in ways that make the thing better-or-worse at happening again. Personally I think this applies to all coherently-causal systems.. still trying to figure out whether to believe QM is fully causal or not! (Currently seems like it might be a mixture?)

stevenalowe 3mo ago

sure seems like a lot of 'em have

dang 3mo ago
Maybe so, but can you please not post unsubstantive comments to Hacker News? We're trying for something a bit different here.
- stevenalowe 3mo ago
  dang, sorry

bebe83949rj 3mo ago

[flagged]

nozzlegear 3mo ago
Humans are the only mammals with genders at all. Are you confusing gender with sex?
- deleted 3mo ago
  [deleted]
- bebe83949rj 3mo ago
  Both are synonyms! Like when pretend "woman" sports are not for woman, but "female" only! Or woman should be in mans only prison, to get raped!
  - nozzlegear 3mo ago
    > Both are synonyms! Not the way you're using them. Dogs and cats don't have genders, but they do have sexes.
- inigyou 3mo ago
  Has that been proven?
  - nozzlegear 3mo ago
    There are some animals that come close to having what we'd call gender roles: bonobos, some other primates (not all), and a bird called a ruff. But as far as we can tell, those animals don't have an internal "I am X gender" self concept. (Interesting note: bonobos are very fluid and change their gender roles depending on the situation and context.)
    - inigyou 3mo ago
      We can't talk to them, so we don't know how they feel, so of course they don't have any known internal feelings. If you observed humans from a distance in their natural habitat for a while you probably also wouldn't find any gender.

hn_throwaway_99 3mo ago

Given that fertility rates are currently plummeting worldwide, the principles of natural selection would dictate that humans are currently undergoing very high selection pressure for specific traits. Basically, any genetic trait that causes people today to think "You know, I think I'm going to remain childfree" is specifically selected against, and any trait that causes people to want more children will be selected for. I'd argue that the invention of reliable birth control was that biggest change in human selective pressures in history. Evolution made sex highly pleasurable and desirable because it often resulted in passing on your genes. That's no longer true with reliable birth control, and with such a huge environmental shift natural selection will act on other avenues that cause people to have children.

gblargg 3mo ago
[flagged]
- chmod775 3mo ago
  One reason our ancestors had plenty of children is that children were a large net-benefit to them. Many modern societies are structured in a way that makes children an economic negative to their parents. From an individuals' POV, the "smart" play is not having children and hope others do. Individuals believe that they do not need children because they have saved up for retirement, not accounting for the fact that if everyone did this and there was nobody left to do any work once they reach retirement age, that money will be worthless and they'll be unable to retire. The alternative is mass-scale immigration, and that's becoming unpopular. For an example of what happens if a society has neither enough children, nor immigration, see South Korea. Poverty among the elderly is rampant and they are increasingly being forced back into the labor market. Many western societies needed to start applying a large multiplier to parental benefits decades ago.
- derektank 3mo ago
  >People aren't born not wanting to have kids, since all their ancestors did. What evidence do you have that all their ancestors wanted to have kids? I can think of a lot of reasons why people may have had kids without necessarily wanting them. They wanted to have sex in an era before birth control. They were pressured into it by the social norms of their local community. They were raped. Etc. I have a lot of criticism of the childfree movement but I think it’s pretty disrespectful to assume they’re not being honest when they say they don’t want to have kids and that they’ve always felt that way.

deepsun 3mo ago

As far as I was taught in college, evolution never stops, but we're just too short lived to notice that. We _may_ notice some very tiny blip on timescales of several hundred years, but last really noticeable traits happened many thousands years ago. However, cultural/society/educational evolution happens much-much faster (but is also much-much weaker, can disappear on just a few weeks).

Grimblewald 3mo ago
also, technology largly exists to remove the discomfort of evolutionary pressure. This doesnt mean the mutations that give rise to evolutionary changes in the population, but it does mean we've removed or mititaged many of the mechanisms which would select for specific traits. Again, we would naturally still change, but not in the the way or at the rate otger organisms continue to or at which we would sans technology.
- plastic-enjoyer 3mo ago
  > also, technology largly exists to remove the discomfort of evolutionary pressure. I think this is a very limited way to view technology
  - Grimblewald 3mo ago
    sure, it can be. However, I'd argue in a large amount of cases it fits. Agriculture, medicine, transport combine massivly lower the bar for base survival let alone reproduction on all skill checks otgerwise place don metabolism, physical fitness, immunological fitness. This isnt me taking a dig either, I am among the ranks of those who would be dead without these modern "comforts" but as a reuslt if there is a genetic driver for my lack of fitness (which there is) those genes are now not being selected against. Perhaps we don't think of tech as an evolution stop, but really most of the comfort and conveniance it brings are won by removing the discomfort otherwise applied as evolutionary pressure. Can't live in this place? no worries, create air conditioning. Can't calculate this? no worries, computers. Can't feed all these mouths because hunting and gathering wouldnt work? no worries, agriculture. Tech, in my opinion, offers most of its perceived benefits by removing natural pressures to move, stop, or adapt from ourselves.

jona-f 3mo ago

Who said we stopped evolving? Evolution is slow cause we are many. Another garbage clickbait press release that butchers the science.

_moof 3mo ago

I can't find the source now but an idea that really stuck with me is that evolution happens on the margins. If a 0.0001% increase in the height of a giraffe makes it 0.0001% more likely that the giraffe will survive and reproduce, then in 1 million years giraffes as a species will become taller. As for humans: I mean, duh? The selective pressures faced by humans have changed radically in the time we've been around.

deleted 3mo ago

[deleted]

jiggawatts 3mo ago

It is well established that evolution is driven not only by fitness in the trivial sense of "survival or death", but in large part by mate selection. (Disclaimer: The rest is a personal theory with zero scientific support.) This begs the question: selection based on what? In many bird species it is the complexity of the male's song, or the colourful beauty of his feathers. There are "dances" and courtship rituals in many animals, including even insects. Humans almost certainly also subject to evolution caused by the evolutionary pressures of mate selection! This is best said by Anthony Hokpins in Westworld: https://www.youtube.com/watch?v=OjsGJOXhPGU https://www.youtube.com/watch?v=OjsGJOXhPGU "I read a theory once that the human intellect was like peacock feathers. Just an extravagant display intended to attract a mate. All of art, literature, a bit of Mozart, William Shakespeare, Michelangelo, and the Empire State Building—just an elaborate mating ritual. Maybe it doesn't matter that we have accomplished so much for the basest of reasons. But, of course, the peacock can barely fly. It lives in the dirt, pecking insects out of the muck, consoling itself with its great beauty." Which is a good bit of drama, but... if true, what are the consequences for the evolution of the human species? Assume for a moment, that yes, women are attracted to male intelligence, which men show off with music, art, and "great works". The obvious immediate effect is that this causes the average intelligence of Homo Sapiens to increase over time. But the secondary effect is more interesting: judging intelligence benefits from more intelligence! As the next generation of women inherit greater intelligence, they become better judges of male intelligence, more picky and precise. This forces male intelligence to increase ever faster to keep up with the "rising demand". Rinse and repeat. I can't prove, but strongly suspect that this is the case. Birds of Paradise become "more beautiful" on the scale of aeons because more beauty in the males doesn't improve the judgement of the females. Humans become more intelligent on the scale of mere millenia because more intelligence does improve the judgement of the females.

Terr_ 3mo ago
> > just an elaborate mating ritual. You might find the book Blindsight interesting, since... Well, to avoid spoilers, I'll just say the story doesn't put our concept of intelligence on the usual top-of-creation pedestal.
- 3mo ago

keeda 3mo ago

Am I the only one who thought that was a given based on phenomena like this: https://www.nationalgeographic.com/science/article/bajau-sea-nomads-free-diving-spleen-science https://www.nationalgeographic.com/science/article/bajau-sea... we all are not quite freediving most of our waking lives, but the daily pressures of modern urban living must be exerting a similar level of evolutionary pressure on us.

chr15m 3mo ago

Lactose tolerance is a classic example of a recently evolved trait. https://en.wikipedia.org/wiki/Lactase_persistence https://en.wikipedia.org/wiki/Lactase_persistence

saidnooneever 3mo ago
I for one am glad that now people can have a healthy serving of cheese without the side effects. Do you think we will become more and more tolerant? like with the happy people? One day maybe we can drink only milk and eat only cheese, even on the sweltering summer heat. For me those days i still struggle and sometimes reluctantly find myself reverting back to greens
- serious_angel 3mo ago
  > Do you think we will become more and more tolerant? I do not, sorry. This question feels quite odd to see, too, frankly. I became intolerant in ~20 years just "because", and only when I checked at medics for non-related general tests, and out of the blue it showed on the results paper. And And this is when I never had any abnormal meals with it, but just casually and normally as any other one, I believe. It was like a blow to the gut... This intolerance changes the life much. It makes impossible to have any meals with other people in group or be afraid of trying anything that may have any kind of milk in it, and you may imagine that there's so much of it out there... including many kinds of common bread, cakes, candies, certain cheese, coffee as Latte, Cappuccino etc. The aftereffect depends on the person, and some have diarrhea-type issues, but in the case here, it only the stomach that hurts so much as if someone cuts it inside-out. There are tablets, but... it's always dear scary and it doesn't help much... Currently, I am ~1.75m and ~63kg in ~40 years old woman, and I see more of this intolerance become normalized in European and Asian countries where some stores sell lactose-free holy milk and some cafes offer a so much appreciated lactoze-free lovely coffee...
  - jareklupinski 3mo ago
    lactaid

cubefox 3mo ago

The most terrifying evolutionary trend is that nowadays fertility is negatively correlated with intelligence. That is, there is a strong selective pressure for humans to become dumber.

HarHarVeryFunny 3mo ago
Maybe AI will fix this. We'll all be out of work, surviving off our own wits, and ability to survive and thrive will go back to being based on things we judge as desirable.
- cubefox 3mo ago
  I don't see how this would fix IQ decline.
  - HarHarVeryFunny 3mo ago
    I'm half joking, but what I meant was that self-sufficiency seems to be more demanding than many jobs, so success might be more dependent on characteristics that used to be more important in the past, and got us to where we are today. On reconsideration, it's not clear how much of our increase in intelligence over the last few million years is due to the greater success of more intelligent individuals, or rather the greater success of more collectively intelligent populations, based on language and communication etc. Again, half-joking, but it's interesting to consider if AI as an "intelligence leveler" could eventually have an effect. If we all have access to super-intelligence, then does our own individual intelligence matter that much? You could even speculate that the invention of AI puts a cap on the intelligence of a species since then perhaps the success of the species depends more on the intelligence of the AI, not of the species itself.
    - cubefox 3mo ago
      I think our intelligence is crucial to make sure that we won't get replaced by AI.

metalman 3mo ago

the problem is that humans are modifying the environment, orders of magnitude faster than evolution can keep up with, and many of the "features" of our modern technological cities are prouncedly geared towards our worst/best (non) survival instincts, as from an evolutionary perspective we are all living in the valley of infinite plentitude, and survival of the fittest has taken on an entirely other definition.

inigyou 3mo ago
Evolution doesn't find a solution to a problem. Instead, it finds all possible solutions. Ones which don't fit through the problem are culled. During happy times, mutation creates a variety of individuals. During stressful times, individuals who happen to have traits that help them weather the stress are the ones who survive more. Sometimes much more. That's when the evolution happens. Both parts can happen concurrently and gradually, like those butterflies who turned black to hide in coal smoke.
- lotsofpulp 3mo ago
  >Both parts can happen concurrently and gradually, like those butterflies who turned black to hide in coal smoke. Do you mean the black ones survived and procreated?
  - inigyou 3mo ago
    Yes, but gradually. The blacker ones reproduced more. There weren't any black ones at the beginning The opposite is the Black Death. Some people had more aggressive immune systems that were able to destroy the bacteria before it destroyed them. This is thought to have caused a jump increase in the "immune aggressivity" of European populations, causing more autoimmune diseases in subsequent generations.

chaz6 3mo ago

Does anybody think that evolution just stops? A species only stops evolving when it is wiped out.

vitally3643 3mo ago
Or when they develop a society which removes all evolutionary pressures. Evolution isn't magical, it's purely probabilistic. You can drive the probabilities down real low and then genetically engineer the rest away.
- HarHarVeryFunny 3mo ago
  As long as all offspring aren't 100% exact clones of the parents then you'll get evolution. In practical terms it would be impossible to genetically engineer away genetic variation (assuming you could convince people to stop having sex and visit your cloning lab instead). There are all sorts of things like DNA damage, horizontal gene transfer, and just the inherent error potential of reproduction that you would never be able to eliminate. Of course it would also be highly undesirable to stop genetic variation, since that's what gives a species the ability to adapt and survive.
  - seanmcdirmid 3mo ago
    You’ll get mutations, not evolution. You still need natural selection to sort out the mutations which gives us evolution, and that’s a bit harder now that we don’t have to worry about being hunted down by tigers. Anyone can reproduce and pass down their genes, so what mutations are we currently selecting? Maybe looks, but I doubt even that.
    - saltcured 3mo ago
      You're saying that as if survival doesn't remain an evolutionary pressure. Life is inherently demanding, and many mutations are lethal. So, at best, the argument seems to be that the surviving gene pool may get more complex with lots of optional mutations which all coexist? Could we end up like some plant species full of cultivars where larger swathes of genes are expressing differently out of a very convoluted library? If you're envisioning medical science to allow people to survive with otherwise lethal mutations, I would say that is not an escape from evolution. Instead, you've revised the reproductive cycle to include more epigenetic components. The species is still the survivable set of genes and cultural practices which are evolving together, and which terminate when they no longer function as a system.

gweinberg 3mo ago

"Most research during the past two decades hinted that human evolution has largely slowed or changed so subtly that existing tools couldn’t detect it; evidence seemed to suggest that civilization put humans beyond the reach of natural selection." There has never been the slightest shred of evidence to that effect, anywhere, ever.

ASalazarMX 3mo ago
It's logical. Survival of the fittest was initially driven by the environment; then we formed civilizations, and culture influenced what "fittest" was. Now we have technology that defines the "fittest" further. The urban fittest of the future could end up being people succesful enough to pay for advanced medicine. Evolution still happens when creatures reproduce at different ratios, but civilization and tech allows people to survive and/or reproduce when they naturally wouldn't.
- vinceguidry 3mo ago
  I love it. Claim gets made, it's pointed out that there's no evidence for said claim, claim gets justified anyway with some version of "it's logical / rational / stands to reason." All it amounts to is 'sounds good to me'.
  - ASalazarMX 3mo ago
    It doesn't just "sound good to me", you can watch culture and technology influence reproduction, the main driving force of evolution. For example, today we can sit for hours and thrive, while a hunter-gatherer or farmer would starve sitting around all day. Our bodies protest, but we manage to reproduce, and treat or palliate the ailments that come with sedentarism. We surely are evolving to better tolerate sedentarism, but it's slowed down because medicine allow the unfit to sedentarism to survive and reproduce instead of dying early. You can see the delay of evolution, allowing the biologically unfit to reproduce, at any hospital. Medicine saves or prolongs more lives than ever, and death is the second driving force of evolution. Stephen Hawkins, for example, was diagnosed with ALS and given two years to live, and despite that he had three descendants years after. He couldn't do physical work, but could do great mental work, which our society values. You can correctly argue that our civilization is part of the environment, though. In that case, natural evolution isn't slowing down, it's just going in a different direction than it used to.