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
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.
Evolution is surprising and complicated enough that that might not be the full picture.
People have relatives and relatives have many genes in common.
If there are genetic traits that predispose people to remaining childless, it could wind up that populations with those genes end up with larger branches on their family tree.
It's been a while since I read the Selfish Gene, but its central point is that natural selection is about genes, not individuals.
True, and here's an interesting twist: as you wrote, this is mainly happening due to "I think", so it's primarily on a memetic level. Humans also pass on lots of thought/behavioral aspects to their children (memes). Therefore I'd expect that selection on the behavioral level is happening much faster than on a genetic level.
Idiocracy's "stupid genes win" likely won't happen, my theory is that selection will remove memes (behavioral/thought/cultural patterns) that cause childlessness from the meme pool much faster.
Could also well be that natural selection will rear it's ugly head again first. I previously thought that people rejecting the evolutionary theory (creationists etc) were just backwards and anti-science. But I've realized since that this is a too simple judgement. The ethical implications of evolution are dark. Humans have had a word for selection since the dawn of language - "death".
A bit sad that paraphrasing Paul Watzlawick in this context fits very well: one cannot not participate in evolution.
> my theory is that selection will remove memes (behavioral/thought/cultural patterns) that cause childlessness from the meme pool much faster.
The sociologist Eric Kaufmann wrote a book Shall the Religious Inherit the Earth?, arguing that traditionalist religious groups (such as ultra-Orthodox Jews and the Amish) will become demographically dominant in the long-term (decades and centuries) due to their greater fertility and high retention rates (>80% of their children stay in the group as adults)
I think the possiblities that a minority can leave the group is an important escape valve for them. Now assume that in the future they are going to be not such a minority anymore like today, then what happens? Maybe some oscillation like for Lotka-Volterra situation, perhaps a bit different?
The possibility of defection to mainstream society actually increases the selective pressure against defection-promoting alleles/memes, compared to if that possibility didn’t exist; the mainstream acts as a genetic/memetic sink to absorb those alleles/memes, reducing their prevalence in the next generation.
I think the fact that in e.g. the United States there are multiple such high fertility traditionalist religious minority groups coexisting makes it unlikely any one of them will end up completely dominant in coming centuries. More likely, I think, conservative religious groups will ally together across confessional boundaries to attain shared policy objectives (e.g. government funding of private religious schools). As such, I don’t think the possibility of defection to secular society will disappear; secular people will still exist, just numerically and politically weakened compared to today.
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).
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.
I think this is a common misperception, but it's not accurate. The general idea is that with technology there is less risk of someone dying or not being able to procreate due to their susceptibility to disease (because modern medicine would likely cure them) or their inability to acquire food/resources.
But even if that were 100% true, that just shifts selection pressure elsewhere. For example, your ability to hunt is probably not selected for in modern society, where it would have been in centuries past. But your social standing (and the genetic traits that are beneficial for acquiring that social status) definitely would be, especially in places where there is a large sex imbalance.
We are currently undergoing a major change in reproduction due to the "severing" of the ties between having sex and having children due to modern birth control. Evolution is what caused sex to be so pleasurable/desired in the first place, because having sex greatly increases the chances of someone passing on their genes. The ability to have lots of sex now without having children as a byproduct means there will be natural selection pressure for another impetus for people to have children.
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.
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.
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.
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.
Despite being so famous, I feel like his ideas haven't aged well. His ideas were contentious yet embraced by popular science writers, and there's never been a reckoning.
One should not read or pay much attention to anything Gould wrote or said. (http://cogweb.ucla.edu/Debate/CEP_Gould.html) The amount of damage Gould has done offsets any positives. It's not just even being wrong, indeed you can charitably read that quote as being almost correct (the phrase is "anatomically modern human"); the worst thing he's done is probably to mischaracterize the rest of the field as scientists believing things they don't (or haven't for many decades before he ever tried to address them).
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.
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.
You can observe evolution on much narrower timescales. People were following how covid was evolving after all. Evolution just means some changes to dna. Even identical twin children have some differences between them.
It's more of a function of selection pressure applied to genes per unit time based on some environmental factor, so you'd expect to observe less evolution in narrower timescales simply because it takes few decades for humans to pass on genes versus bacteria or viruses. In the same fashion, if some gene pool is locally optimal(?) against the environmental pressures, it may just stop evolving meaningfully. E.g, If male baldness were reversed easily with a pill or something, the environmental pressure to select those genes would decrease rapidly.
Sounds like they just meant evolution takes longer than that?
To some degree it's true. We have all sorts of variable parameters that are probably different from back then (eg. Average height) but we still have the same body shape, etc
Emphasis should be placed on "everything we call culture and civilization". There is a thought experiment that might help. Imagine we had a time machine, and no scruples, and we could go back and pluck babies from the past to experimentally raise them in modern American families. I'm pretty sure Gould would have argued that babies from 40k years ago would grow up to be behaviourally indistinguishable from modern humans.
Well, evaluating the nature of this thought experiment reveals what you actually believe about human evolution and development. I find it extremely hard to believe that someone from 40k years ago would be indistinguishable from humans today. Believing this requires you to imagine that there are no genetic selection pressures for things like intelligence, behavior, physical ability ... 40k years ago had Earth as an almost entirely different planet. Europe was frozen for most of the year, for example. There were no trees. Very, very hard to believe that people born back then could grow up to sit in front of a laptop today.
All we know basically is that their skeletons are undistinguishable from ours, with a brain the same size as ours (slightly later on average iirc) and what they left, tools and paintings, look just like what we can do as well (behavioural modernity, thought to arise some time between -100 000 and -40 000).
You can find it hard to believe, but I think most people in that field agree that humans from the last 40 000 years would grow up as modern humans without problems.
The fondamental thing here is that humans 40k years ago could live in the toundra because we can live in the toundra today, and they had a similar behaviour to ours. So they made clothes and fires for the cold, and weapons for hunting the local fauna, just like we do. And they avoided actually desolate areas because they could not live without food.
That's why the colonisation of colder areas happened at about the time of behavioural modernity. Before that, humans where anatomically modern (mostly identical to us) but did not have the cultural equipment to deal with difficult environments.
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.
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.
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.
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.
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.
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.
I believe the traits for humans you should look at are not physical like strength, but social. People with poor social skills are less likely to reproduce in our society. Likewise, culture (and hence memetic evolution) influences birth rates quite a bit and is passed on from parents to children.
Well notably the loss of skin pigmentation evolved in two different ways after migration into Europe and separately into East Asia. There is strong selective pressure in Africa so pigmentation remains there.
And lactase persistence is quite recent. Some people say that Tibetans and some S E Asians are particularly adapted as well to their local environment of high altitude and sea diving but I don’t know anything about that.
Genetic drift is essentially random. Alleles at loci more than a few hundred thousand base pairs away are unaffected.
In contrast, an allele under selection pressure drags along large chunks of the chromosome on which it occurs. Statistically, the effect is different. You start to see long-range correlations across the chromosome.
The MHC region, which contains genes that govern many functions of the immune system, has been under continuous selection pressure resulting in extraordinary variability, but also very strong long range correlations spanning the region. It's unlike anywhere else in the human genome. This is a clear signature of evolution.
>> might win competitions and make a bunch of money
You mean, they might be more likely to have lots of offspring than someone who was disabled and living on government assistance?
Or 500 years ago, be more likely to slaughter the men and rape the women of a neighboring kingdom, than those who stayed home?
Or for a trait closer to my heart, be adept at handling the intellectual requirements of surviving exile and persecution?
You know it's the success they confer toward reproduction that causes traits to survive or not, right? Without reproduction, of course one generation's genetic noise is just noise. And longevity traits don't survive if they hamper reproduction. Just the opposite: Lots of traits that succeed because they improve the chances of breeding are the worst possible things you would want for longevity. Risk taking behavior and all manner of psychoses have survived and thrived for millenia not because the individuals with them live long, but because they breed prolifically.
It is far more complicated than you might gleam. Why don't cheetas run at 300mph right now? They'd catch everything in the bush right? It is a dance of course. Once you go so fast there's probably diminishing returns of what you'd additionally catch. There is also the additional caloric demands to support that top speed. Plus whatever other changes have to be made to hit that speed, e.g. maybe lighter but weaker bones. Surprising to say, a 300mph cheetah might actually be less fit than one at typical speed.
This is certainly true for humans as well. Does being faster, stronger, better vision, better hearing, necessarily mean you will beat a "worse" human for calories to survive and also mating opportunity? Nope. And that is why we aren't all 9 foot tall space jam monsters. It isn't about being a perfect specimen, but a good enough one to keep on a little longer.
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.
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.
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?)
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.
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.
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.
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!
"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.
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.
Something I noted -- trying to avoid spoilers here -- is that Rorschach is awfully similar to LLMs, but the book pre-dates ChatGPT by several years, which I feel says everything you need to know about how well the author foresaw the future.
also, women and men mostly have the same genes. Anything that affects one affects the other, by default.
This fact is itself subject to evolution. (In birds, it's the women who have the different chromosome.) Mammals may have evolved to share most genes between sexes because that allows either sex to benefit from traits evolved by the other one, and not solely because it's the easy way to store genes.
> I can't prove, but strongly suspect that this is the case.
I think you can benefit from reading Franz de Waal works. He was a primatologist and he had a similar ideas. Though according to him intelligence was (is) not just a useless "peacock feather", he adds one more block in your feedback loop: hierarchy. Intelligence is used by males to play political games to raise their social status. Social status influences frequency of reproduction for males, so there is a natural (?) selection for political success which depends on good looks, physical fitness and intelligence.
It works for a lot of species but higher primates somehow got enough intelligence to make it dominate good looks and physical fitness and then the positive feedback loop led to evolution of Homo Sapience.
I especially like this theory because it explain why people lose all their pretense to be rational when it comes to politics: human mind is political first. Language, logic, rational discourse are later inventions on top of a political mind. They can work in a neutral environment but when it comes to politics Nature gets the upper hand, and the cultural intellectual sediments of rational thought are wiped instantly, and people's intelligence drops to levels of chimpanzee's: keep alliance with the strongest alpha if you can, rational discourse be damned. One needs a very strong mental discipline to resist it.
> Humans become more intelligent on the scale of mere millenia because more intelligence does improve the judgement of the females.
This idea doesn't explain how intelligence became so important for females. Your idea is like chicken-and-egg problem, you can explain how chickens and eggs let each other to exist, but not where did the first chicked (or egg) come from. And the idea relies on the assumption that female's opinion matters. It matters for some species and doesn't matter for others. It matters in some societies and doesn't matter in others.
> 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.
When I read this I thought you'd go about role of sexual dimorphism in evolution and Vigen Geodakyan evolutionary theory of sex[1], but no. Still you may be interested, though I want to note, I don't know if the theory is "scientific" or not. I'm not a biologist to judge, and I didn't have luck to find some kind of a scientific debate about it. Some objections to the theory, but not full-blown attempts to dismantle it. And I think the theory is not politically correct: it implies that roles of males and females in evolution are different. It is not bad per se, but you know how (most of) people think (with their political mind borrowed from chimpanzee): if roles are different in evolution, then you can argue for a society change that would mirror it and would give you some privileges and raise your social status against some others, and then you would get new kind of Nazis trying to genocide half the population of Homo Sapience.
Evolution does not necessarily mean getting smarter or better in any way other than more adapted to the environment (natural and artificial). We could be getting stupider and more violent if that leads to hoarding more food and reproducing more in the given context. It's also not evenly spread throughout the species, some could be evolving various abilities while the rest are stuck in a plateau or even regressing.
Similarly with social progress. There is a common myth of linear progress through history, where humanity now is better than we were a century ago, a millenium ago, and ten thousand years ago. In some ways we're better, in other ways we don't even know what we've forgotten and lost.
What we want is conscious evolution, where we shape the direction that we wish to evolve towards. Unfortunately with the state of politics we've lost decades of progress in a very short time.
Traditionally, harming other people and the environment has made it easier to feed your own children (or at least the children of your tribe) and have more of them.
We are parasites in a sense. Parasites are far more common than symbiotes. It is much quicker evolutionary speaking to up and have a parasitic relationship than to have the far more many step changes to actually taper that parasitic relationship into a symbiotic one that doesn't kill the host off. Doesn't bode well for ourselves though, as this implies we need to get decimated by the climate crisis to pare down our population to the small subset that gives a shit about it and also is smart enough to adapt to or slow the process, and things would only get better once this population reseeds the planet.
Because that isn't what evolution does. Evolution is the process whereby traits that make reproduction more likely under selective pressures become more common. There is nothing in that process that necessarily implies a lack of harm to each other or the environment.
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!?!
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.
Lactose tolerance is a classic example of a recently evolved trait.
https://en.wikipedia.org/wiki/Lactase_persistence
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
Does anybody think that evolution just stops? A species only stops evolving when it is wiped out.
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.
Evolution is surprising and complicated enough that that might not be the full picture.
People have relatives and relatives have many genes in common.
If there are genetic traits that predispose people to remaining childless, it could wind up that populations with those genes end up with larger branches on their family tree.
It's been a while since I read the Selfish Gene, but its central point is that natural selection is about genes, not individuals.
True, and here's an interesting twist: as you wrote, this is mainly happening due to "I think", so it's primarily on a memetic level. Humans also pass on lots of thought/behavioral aspects to their children (memes). Therefore I'd expect that selection on the behavioral level is happening much faster than on a genetic level.
Idiocracy's "stupid genes win" likely won't happen, my theory is that selection will remove memes (behavioral/thought/cultural patterns) that cause childlessness from the meme pool much faster.
Could also well be that natural selection will rear it's ugly head again first. I previously thought that people rejecting the evolutionary theory (creationists etc) were just backwards and anti-science. But I've realized since that this is a too simple judgement. The ethical implications of evolution are dark. Humans have had a word for selection since the dawn of language - "death".
A bit sad that paraphrasing Paul Watzlawick in this context fits very well: one cannot not participate in evolution.
> my theory is that selection will remove memes (behavioral/thought/cultural patterns) that cause childlessness from the meme pool much faster.
The sociologist Eric Kaufmann wrote a book Shall the Religious Inherit the Earth?, arguing that traditionalist religious groups (such as ultra-Orthodox Jews and the Amish) will become demographically dominant in the long-term (decades and centuries) due to their greater fertility and high retention rates (>80% of their children stay in the group as adults)
I think the possiblities that a minority can leave the group is an important escape valve for them. Now assume that in the future they are going to be not such a minority anymore like today, then what happens? Maybe some oscillation like for Lotka-Volterra situation, perhaps a bit different?
The possibility of defection to mainstream society actually increases the selective pressure against defection-promoting alleles/memes, compared to if that possibility didn’t exist; the mainstream acts as a genetic/memetic sink to absorb those alleles/memes, reducing their prevalence in the next generation.
I think the fact that in e.g. the United States there are multiple such high fertility traditionalist religious minority groups coexisting makes it unlikely any one of them will end up completely dominant in coming centuries. More likely, I think, conservative religious groups will ally together across confessional boundaries to attain shared policy objectives (e.g. government funding of private religious schools). As such, I don’t think the possibility of defection to secular society will disappear; secular people will still exist, just numerically and politically weakened compared to today.
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).
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.
I think this is a common misperception, but it's not accurate. The general idea is that with technology there is less risk of someone dying or not being able to procreate due to their susceptibility to disease (because modern medicine would likely cure them) or their inability to acquire food/resources.
But even if that were 100% true, that just shifts selection pressure elsewhere. For example, your ability to hunt is probably not selected for in modern society, where it would have been in centuries past. But your social standing (and the genetic traits that are beneficial for acquiring that social status) definitely would be, especially in places where there is a large sex imbalance.
We are currently undergoing a major change in reproduction due to the "severing" of the ties between having sex and having children due to modern birth control. Evolution is what caused sex to be so pleasurable/desired in the first place, because having sex greatly increases the chances of someone passing on their genes. The ability to have lots of sex now without having children as a byproduct means there will be natural selection pressure for another impetus for people to have children.
> also, technology largly exists to remove the discomfort of evolutionary pressure.
I think this is a very limited way to view technology
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.
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.
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.
Despite being so famous, I feel like his ideas haven't aged well. His ideas were contentious yet embraced by popular science writers, and there's never been a reckoning.
One should not read or pay much attention to anything Gould wrote or said. (http://cogweb.ucla.edu/Debate/CEP_Gould.html) The amount of damage Gould has done offsets any positives. It's not just even being wrong, indeed you can charitably read that quote as being almost correct (the phrase is "anatomically modern human"); the worst thing he's done is probably to mischaracterize the rest of the field as scientists believing things they don't (or haven't for many decades before he ever tried to address them).
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.
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.
I guess I would need to read more of what Gould wrote. For example, did he claim that evolution in other species also stopped?
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.
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.
You can observe evolution on much narrower timescales. People were following how covid was evolving after all. Evolution just means some changes to dna. Even identical twin children have some differences between them.
It's more of a function of selection pressure applied to genes per unit time based on some environmental factor, so you'd expect to observe less evolution in narrower timescales simply because it takes few decades for humans to pass on genes versus bacteria or viruses. In the same fashion, if some gene pool is locally optimal(?) against the environmental pressures, it may just stop evolving meaningfully. E.g, If male baldness were reversed easily with a pill or something, the environmental pressure to select those genes would decrease rapidly.
Sounds like they just meant evolution takes longer than that?
To some degree it's true. We have all sorts of variable parameters that are probably different from back then (eg. Average height) but we still have the same body shape, etc
Emphasis should be placed on "everything we call culture and civilization". There is a thought experiment that might help. Imagine we had a time machine, and no scruples, and we could go back and pluck babies from the past to experimentally raise them in modern American families. I'm pretty sure Gould would have argued that babies from 40k years ago would grow up to be behaviourally indistinguishable from modern humans.
Well, evaluating the nature of this thought experiment reveals what you actually believe about human evolution and development. I find it extremely hard to believe that someone from 40k years ago would be indistinguishable from humans today. Believing this requires you to imagine that there are no genetic selection pressures for things like intelligence, behavior, physical ability ... 40k years ago had Earth as an almost entirely different planet. Europe was frozen for most of the year, for example. There were no trees. Very, very hard to believe that people born back then could grow up to sit in front of a laptop today.
All we know basically is that their skeletons are undistinguishable from ours, with a brain the same size as ours (slightly later on average iirc) and what they left, tools and paintings, look just like what we can do as well (behavioural modernity, thought to arise some time between -100 000 and -40 000).
You can find it hard to believe, but I think most people in that field agree that humans from the last 40 000 years would grow up as modern humans without problems.
Sorry, you're claiming that people who lived in a desolate tundra 40k years ago are the same as you and me.
Can you be more specific? There's both a hardware and firmware element to this. Perhaps the hardware element is transferable.
The fondamental thing here is that humans 40k years ago could live in the toundra because we can live in the toundra today, and they had a similar behaviour to ours. So they made clothes and fires for the cold, and weapons for hunting the local fauna, just like we do. And they avoided actually desolate areas because they could not live without food.
That's why the colonisation of colder areas happened at about the time of behavioural modernity. Before that, humans where anatomically modern (mostly identical to us) but did not have the cultural equipment to deal with difficult environments.
For the average person considering this question it also goes without saying that it's hard to grasp the time scales involved.
There are a couple of species that remain essentially unchanged for the last couple million years. Why can't humans become one of them?
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.
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.
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.
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.
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.
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.
Right, but, those people are wrong. "This trait didn't die out in 2 generations. Evolution is over!"
I believe the traits for humans you should look at are not physical like strength, but social. People with poor social skills are less likely to reproduce in our society. Likewise, culture (and hence memetic evolution) influences birth rates quite a bit and is passed on from parents to children.
Well notably the loss of skin pigmentation evolved in two different ways after migration into Europe and separately into East Asia. There is strong selective pressure in Africa so pigmentation remains there.
And lactase persistence is quite recent. Some people say that Tibetans and some S E Asians are particularly adapted as well to their local environment of high altitude and sea diving but I don’t know anything about that.
Genetic drift is essentially random. Alleles at loci more than a few hundred thousand base pairs away are unaffected.
In contrast, an allele under selection pressure drags along large chunks of the chromosome on which it occurs. Statistically, the effect is different. You start to see long-range correlations across the chromosome.
The MHC region, which contains genes that govern many functions of the immune system, has been under continuous selection pressure resulting in extraordinary variability, but also very strong long range correlations spanning the region. It's unlike anywhere else in the human genome. This is a clear signature of evolution.
>> might win competitions and make a bunch of money
You mean, they might be more likely to have lots of offspring than someone who was disabled and living on government assistance?
Or 500 years ago, be more likely to slaughter the men and rape the women of a neighboring kingdom, than those who stayed home?
Or for a trait closer to my heart, be adept at handling the intellectual requirements of surviving exile and persecution?
You know it's the success they confer toward reproduction that causes traits to survive or not, right? Without reproduction, of course one generation's genetic noise is just noise. And longevity traits don't survive if they hamper reproduction. Just the opposite: Lots of traits that succeed because they improve the chances of breeding are the worst possible things you would want for longevity. Risk taking behavior and all manner of psychoses have survived and thrived for millenia not because the individuals with them live long, but because they breed prolifically.
It is far more complicated than you might gleam. Why don't cheetas run at 300mph right now? They'd catch everything in the bush right? It is a dance of course. Once you go so fast there's probably diminishing returns of what you'd additionally catch. There is also the additional caloric demands to support that top speed. Plus whatever other changes have to be made to hit that speed, e.g. maybe lighter but weaker bones. Surprising to say, a 300mph cheetah might actually be less fit than one at typical speed.
This is certainly true for humans as well. Does being faster, stronger, better vision, better hearing, necessarily mean you will beat a "worse" human for calories to survive and also mating opportunity? Nope. And that is why we aren't all 9 foot tall space jam monsters. It isn't about being a perfect specimen, but a good enough one to keep on a little longer.
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.
Am I the only one who thought that was a given based on phenomena like this:
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.
Who said we stopped evolving? Evolution is slow cause we are many. Another garbage clickbait press release that butchers the science.
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?)
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.
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.
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.
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
"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.
> > 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.
Read it twice already!
Something I noted -- trying to avoid spoilers here -- is that Rorschach is awfully similar to LLMs, but the book pre-dates ChatGPT by several years, which I feel says everything you need to know about how well the author foresaw the future.
also, women and men mostly have the same genes. Anything that affects one affects the other, by default.
This fact is itself subject to evolution. (In birds, it's the women who have the different chromosome.) Mammals may have evolved to share most genes between sexes because that allows either sex to benefit from traits evolved by the other one, and not solely because it's the easy way to store genes.
Did you know men have a genetic breast size?
> I can't prove, but strongly suspect that this is the case.
I think you can benefit from reading Franz de Waal works. He was a primatologist and he had a similar ideas. Though according to him intelligence was (is) not just a useless "peacock feather", he adds one more block in your feedback loop: hierarchy. Intelligence is used by males to play political games to raise their social status. Social status influences frequency of reproduction for males, so there is a natural (?) selection for political success which depends on good looks, physical fitness and intelligence.
It works for a lot of species but higher primates somehow got enough intelligence to make it dominate good looks and physical fitness and then the positive feedback loop led to evolution of Homo Sapience.
I especially like this theory because it explain why people lose all their pretense to be rational when it comes to politics: human mind is political first. Language, logic, rational discourse are later inventions on top of a political mind. They can work in a neutral environment but when it comes to politics Nature gets the upper hand, and the cultural intellectual sediments of rational thought are wiped instantly, and people's intelligence drops to levels of chimpanzee's: keep alliance with the strongest alpha if you can, rational discourse be damned. One needs a very strong mental discipline to resist it.
> Humans become more intelligent on the scale of mere millenia because more intelligence does improve the judgement of the females.
This idea doesn't explain how intelligence became so important for females. Your idea is like chicken-and-egg problem, you can explain how chickens and eggs let each other to exist, but not where did the first chicked (or egg) come from. And the idea relies on the assumption that female's opinion matters. It matters for some species and doesn't matter for others. It matters in some societies and doesn't matter in others.
> 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.
When I read this I thought you'd go about role of sexual dimorphism in evolution and Vigen Geodakyan evolutionary theory of sex[1], but no. Still you may be interested, though I want to note, I don't know if the theory is "scientific" or not. I'm not a biologist to judge, and I didn't have luck to find some kind of a scientific debate about it. Some objections to the theory, but not full-blown attempts to dismantle it. And I think the theory is not politically correct: it implies that roles of males and females in evolution are different. It is not bad per se, but you know how (most of) people think (with their political mind borrowed from chimpanzee): if roles are different in evolution, then you can argue for a society change that would mirror it and would give you some privileges and raise your social status against some others, and then you would get new kind of Nazis trying to genocide half the population of Homo Sapience.
[1] https://www.evolocus.com/textbooks/geodakian2011.pdf
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/
sure seems like a lot of 'em have
Maybe so, but can you please not post unsubstantive comments to Hacker News? We're trying for something a bit different here.
If that's true. Why haven't we evolved into a species that doesn't harm each other or the environment?
Evolution does not necessarily mean getting smarter or better in any way other than more adapted to the environment (natural and artificial). We could be getting stupider and more violent if that leads to hoarding more food and reproducing more in the given context. It's also not evenly spread throughout the species, some could be evolving various abilities while the rest are stuck in a plateau or even regressing.
Similarly with social progress. There is a common myth of linear progress through history, where humanity now is better than we were a century ago, a millenium ago, and ten thousand years ago. In some ways we're better, in other ways we don't even know what we've forgotten and lost.
What we want is conscious evolution, where we shape the direction that we wish to evolve towards. Unfortunately with the state of politics we've lost decades of progress in a very short time.
Traditionally, harming other people and the environment has made it easier to feed your own children (or at least the children of your tribe) and have more of them.
True for plants too. Black walnut tree not only has a canopy to stymie nearby competitors, it even produces a herbicide.
We are parasites in a sense. Parasites are far more common than symbiotes. It is much quicker evolutionary speaking to up and have a parasitic relationship than to have the far more many step changes to actually taper that parasitic relationship into a symbiotic one that doesn't kill the host off. Doesn't bode well for ourselves though, as this implies we need to get decimated by the climate crisis to pare down our population to the small subset that gives a shit about it and also is smart enough to adapt to or slow the process, and things would only get better once this population reseeds the planet.
Because we became an incredibly successful species doing just that.
Because that isn't what evolution does. Evolution is the process whereby traits that make reproduction more likely under selective pressures become more common. There is nothing in that process that necessarily implies a lack of harm to each other or the environment.
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!?!
Because it's game-theory-optimal to kill everyone unrelated to you, but not too much.
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.