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
> 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...
I was the same for almost 40 years of my life. A year ago I stumbled upon this video https://www.youtube.com/watch?v=h90rEkbx95 "I fixed my lactose intolerance -- by chugging ALL the lactose" and made an experiment myself. It was horrible but it worked - I can now eat milk products. It is DIFFERENT from the people who can naturally eat lactose. For example, I cannot eat whey protein, or drinking raw milk is still a gamble, but butter, cheese, any fermented products like kefir or yogurt is not an issue for me any more. Another difference is that it basically works on a symbiotic level, it's not me who digests that milk stuff but the gut bacteria that I grown with this method. Therefore, when I do not eat milk products for a long time I gradually lose ability to digest lactose, or when I take antibiotics, I also can lose it, but restoring it is easy - just eating a lot of yogurt restores the ability in a couple of days. I strongly suggest anyone suffering from lactose intolerance to try it.
"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.
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.
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."
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.
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 point I'm making is that we use technology to solve discomforts, and discomfort tends to be something which would otherwise manifest as evolutionary pressure. This doesn't remove the fact we will change, but it does impact our trajectory. Perhaps one such direction of change is we go from having low variance with a moving mean, to a static mean with increasing variance.
so, we've removed much of the historical pressure but this doesnt mean, like I said, mutations stop. It simply means our environment is now less selective or selects for things we dont yet measure or understand.
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.
There's a number of species that seem to have remained unchanged for thousands or even millions of years. So yes, under the right conditions a species can basically stop evolving. Maybe some future thing would cause them to begin to evolve again but the doldrums of evolution are indefinite.
I'm also not sure where the line between selective breeding and "evolution" , I wouldn't consider a Pomeranian an "evolution" of a wolf (though I guess it is a different species). Is any persistent genetic change "evolution"?
As for humans in general we've effectively eliminated most sources of selection, survivability really isn't an issue anymore, and fecundity is largely random, pretty much anyone can have kids, or choose not to have kids. The strongest thing we're probably selecting for right now is Mormonism and even they aren't making a dent in evolution.
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.
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.
I'm sure if you looked at fertility rates across the globe, broken down by location/race/religion and other demographics, you'd find plenty of differences - some very large.
Yes, ability to fend off (or avoid) a tiger attack is not much of a factor nowadays, but even something as simple as a religion that encourages having large families, and encourages marrying within religion (you don't need to live on an island to be somewhat genetically isolated) will have an effect.
As far as survival (not dying) goes, I'm guessing that risk appetite, and certain specific forms of it (e.g. fear of heights) has a genetic component, and it looks like base jumpers and free soloists are experiencing selection pressure!
In the modern world there is also a lot of truth to the premise of the nominally satirical movie "idiocracy", where it's not things we regard as positive (strength, intelligence, etc) that drive reproductive success, but in fact the opposite, with birth rates among the unintelligent often higher than that among the intelligent (who are prone to worrying about having kids).
What tends to drive evolution the most seems to be occasional rapid shifts in the environment rather than stable selection pressures. For example, we were lucky that COVID-19 wasn't worse than it was, but nonetheless by definition those who died were those with immune systems less well prepared for the new threat, and the human species as a whole has now slightly "evolved" to be better able to survive that selection pressure.
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.
Global travel has no doubt caused the gene pool to become more homogenous, but yet there are still clear differences between people from many parts of the world.
Isolation (really meaning tendency not to inter-breed) doesn't have to be physical - it can be cultural too, and it seems this isn't limited to humans - many animal species that are on the cusp of speciation (lions/tigers, horses/donkeys, etc) share the same habitat and are just choosing to avoid each other.
In any case, "isolated" populations are only necessary for speciation, not for evolution. Even a single drifting gene pool is going to evolve to adapt to the changing environment, since individuals will still differ genetically. Whatever the environment throws at you will cause some individuals to do better than others (e.g. you survived the Ebola outbreak, others didn't), and these fitter genetics will then spread in the gene pool.
We will never remove all evolutionary pressures short of a totalitarian society that makes sure every single person has exactly the same probability of reproducing.
We have changed evolutionary pressures, but certainly not removed them.
Do you really believe that everyone in society is precisely equally likely to reproduce? No inheritable traits liable to move the needle one way or another?
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.
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).
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.
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.
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.
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
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.
Crocodiles live in the river and mate with crocodiles in the same river.
Humans live in diverse ecosystems from artic to desert to city, each with differing environmental challenges, and mate with whoever they fancy when they swipe right.
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.
>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
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 !
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.
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.
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.
Why did you just assume there are genes that predict "not wanting children"? It's happening uniformly all around the world, and is much better predicted by things like wealth and freedom than anything else: cultural reasons, not heredity.
I think you've misunderstood my point. To clarify, there was strong selection pressure in the past to "make sex desirable" (and obviously I'm oversimplifying a lot here, but the premise still holds) because that was enough to ensure that passing on your genes was the result a large percentage of the time.
Now, though, birth control has broken that connection between "having sex" and "making babies", so now "making sex desirable" no longer is enough of a trigger that results in passing on your genes. So, in that sense, the environment in which humans reproduce has changed drastically, in a short period of time. So now there should be strong selection pressure for people to have children beyond just making sex enjoyable. Whether that shows up in a stronger innate desire for children themselves or whatever I won't speculate on - I'm just making the point that widespread birth control is a huge change to humans' environment to which natural selection should act on, by definition. What I am not saying is that "not wanting children" currently is the result of some fundamental genetic difference between sub-populations.
I think my point still stands? For selective pressure to select anything, there has to be preexisting genes that predict how much someone wants kids. And again, cultural and material factors are so much more important than genetic ones on the matter, that I don't believe the latter has any quantifiable effect.
It is safe to assume pretty much any proclivity has some, however minor, genetic basis. Separated twin studies have shown enough similarities in basically every aspect of personality that it's a plausible bet.
All over the world, some groups are deciding not to have kids and some are. Globally declining fertility rate says nothing about genetic proclivity to want children unless fertility rate goes to zero.
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.
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.
>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.
Birth control is older than the Bible[1], it just wasn't as effective. Humanity as a whole was very aware how babies come to be.
Ways to have fun without coitus aren't a recent invention either.
Human reproduction and raising children is an unusually taxing, time-, and resource-intensive process, which is why we've applied our considerable intellect to plan for that since forever.
I've read that wikipedia article, and I got the impression that to say that birth control just wasn't as effective is an understatement. One more my finding: the idea of planning your family is relatively modern: Malthusians promoted it widely. It doesn't mean people were not thinking along these lines before, but our widespread understanding of how important it is is mostly a modern phenomena. Like the idea to postpone a marriage and reproduction was not very popular before modernity. We've applied our considerable intellect to invent these things and to make not so smart people to be aware of our findings, but these are very recent ideas. In agrarian world you need a lot of people to feed your armies, so any attempts at birth control would be deemed illegal, amoral or whatever. Kings and popes would do anything to stop people from slowing down their reproduction. Which they did, witch hunt clearly stated that witches are guilty of killing yet unborn babies, ie abortions.
Weren't these more about "human population planning"?
> the idea of planning your family is relatively modern
The term "family planning" is. The general concept is not, which is why we have two thousand year old papyrus talking about birth control.
Note that at no point I used the word "family" - because just our modern understanding of a family will muddy any attempt to compare to historical fact.
Involuntary reproduction has been a tiny tiny minority of births for the past few millenia at least. It happens and is awful but it should not be construed to constitute a large part of any person's ancestry.
They may be honest when they express themselves initially, but their revealed preference later ends up being very tragic. I know several women, and others who are friends of my wife, that did the "I don't want kids" routine only to realize that this was a huge mistake and enter the dating market at 37 to find nothing but a wasteland. People can pretend that their own reason can override their biological reality, but only to a point. "I don't want to have kids" means you die alone. Eventually people realize this.
I'm almost 40 and never wanted kids. As a kid, everyone would say things in the context of "when you have kids of your own..." and I always knew that I didn't want them.
If I lived in a world without reliable birth control, I may have ended up with kids I didn't want, but I'm lucky that I have other options.
Kids shouldn't be raised by people who don't want them, and not everyone is born with the biological drive to reproduce.
Your view that [most] people are born wanting kids may be biased from societal pressure and a historical lack of options.
> Stop sharing your opinions. You will literally be extinct soon. Your existence doesn't matter.
What an insane take. You have no idea what that person's contributions are to this world, or how long those contributions will be relevant after they pass.
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.
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.
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.
>> 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.
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.
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.
Yes, but we seem hell bent on creating AI that is smarter than ourselves, and putting it into embodied robotic form as well - humanoid robots, automated factories, AI driven cars and trucks, autonomous fighter planes...
With AI already able to hack into our human-written computer systems, now being trusted to write much of the new code itself(!), it certainly doesn't take a Sci-Fi fantasy to predict an AI agent wreaking major damage or taking control over some system/factory it was able to hack into, in pursuit of the goals it was given.
It really would not be surprising to discover that, even today, some vibe coded system has an unrequested backdoor built into it, that the agent thought (without malice) it might be useful to add.
Right now we truly are building paperclip maximizers. Idiot-savant RL-trained goal-seekers that we're hoping can be controlled via quaint means such as prompts and guardrails.
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?)
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.
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.
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.
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.)
I'm not sure what you're getting at here, you seem to be repeating my point that humans are the only animals we know of with genders. Am I misunderstanding?
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.
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.
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.
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!?!
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.
That's the way evolution works - isolated sub-populations that mostly don't breed with outsiders necessarily diverge.
Of course evolution is essentially directionless, just "survival of the survivors", although over time whole ecosystems of co-evolving animals and plants will necessarily settle into dynamic "attractor states" of semi-stable co-existence, until a spanner is thrown into the works.
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.
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
A lot of cheese is naturally lactose-free. That’s not really where most of the “danger” is for people who don’t tolerate lactose.
> 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...
I was the same for almost 40 years of my life. A year ago I stumbled upon this video https://www.youtube.com/watch?v=h90rEkbx95 "I fixed my lactose intolerance -- by chugging ALL the lactose" and made an experiment myself. It was horrible but it worked - I can now eat milk products. It is DIFFERENT from the people who can naturally eat lactose. For example, I cannot eat whey protein, or drinking raw milk is still a gamble, but butter, cheese, any fermented products like kefir or yogurt is not an issue for me any more. Another difference is that it basically works on a symbiotic level, it's not me who digests that milk stuff but the gut bacteria that I grown with this method. Therefore, when I do not eat milk products for a long time I gradually lose ability to digest lactose, or when I take antibiotics, I also can lose it, but restoring it is easy - just eating a lot of yogurt restores the ability in a couple of days. I strongly suggest anyone suffering from lactose intolerance to try it.
lactaid
"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.
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.
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'.
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.
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.
I think we largly agree.
The point I'm making is that we use technology to solve discomforts, and discomfort tends to be something which would otherwise manifest as evolutionary pressure. This doesn't remove the fact we will change, but it does impact our trajectory. Perhaps one such direction of change is we go from having low variance with a moving mean, to a static mean with increasing variance.
so, we've removed much of the historical pressure but this doesnt mean, like I said, mutations stop. It simply means our environment is now less selective or selects for things we dont yet measure or understand.
> also, technology largly exists to remove the discomfort of evolutionary pressure.
I think this is a very limited way to view technology
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.
Does anybody think that evolution just stops? A species only stops evolving when it is wiped out.
There's a number of species that seem to have remained unchanged for thousands or even millions of years. So yes, under the right conditions a species can basically stop evolving. Maybe some future thing would cause them to begin to evolve again but the doldrums of evolution are indefinite.
I'm also not sure where the line between selective breeding and "evolution" , I wouldn't consider a Pomeranian an "evolution" of a wolf (though I guess it is a different species). Is any persistent genetic change "evolution"?
As for humans in general we've effectively eliminated most sources of selection, survivability really isn't an issue anymore, and fecundity is largely random, pretty much anyone can have kids, or choose not to have kids. The strongest thing we're probably selecting for right now is Mormonism and even they aren't making a dent in evolution.
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.
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.
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.
I'm sure if you looked at fertility rates across the globe, broken down by location/race/religion and other demographics, you'd find plenty of differences - some very large.
Yes, ability to fend off (or avoid) a tiger attack is not much of a factor nowadays, but even something as simple as a religion that encourages having large families, and encourages marrying within religion (you don't need to live on an island to be somewhat genetically isolated) will have an effect.
As far as survival (not dying) goes, I'm guessing that risk appetite, and certain specific forms of it (e.g. fear of heights) has a genetic component, and it looks like base jumpers and free soloists are experiencing selection pressure!
In the modern world there is also a lot of truth to the premise of the nominally satirical movie "idiocracy", where it's not things we regard as positive (strength, intelligence, etc) that drive reproductive success, but in fact the opposite, with birth rates among the unintelligent often higher than that among the intelligent (who are prone to worrying about having kids).
What tends to drive evolution the most seems to be occasional rapid shifts in the environment rather than stable selection pressures. For example, we were lucky that COVID-19 wasn't worse than it was, but nonetheless by definition those who died were those with immune systems less well prepared for the new threat, and the human species as a whole has now slightly "evolved" to be better able to survive that selection pressure.
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.
Evolution happens even without any selection pressures, for example with genetic drift.
That requires isolated populations and we don’t really have that anymore.
Global travel has no doubt caused the gene pool to become more homogenous, but yet there are still clear differences between people from many parts of the world.
Isolation (really meaning tendency not to inter-breed) doesn't have to be physical - it can be cultural too, and it seems this isn't limited to humans - many animal species that are on the cusp of speciation (lions/tigers, horses/donkeys, etc) share the same habitat and are just choosing to avoid each other.
In any case, "isolated" populations are only necessary for speciation, not for evolution. Even a single drifting gene pool is going to evolve to adapt to the changing environment, since individuals will still differ genetically. Whatever the environment throws at you will cause some individuals to do better than others (e.g. you survived the Ebola outbreak, others didn't), and these fitter genetics will then spread in the gene pool.
We will never remove all evolutionary pressures short of a totalitarian society that makes sure every single person has exactly the same probability of reproducing.
We have changed evolutionary pressures, but certainly not removed them.
Do you really believe that everyone in society is precisely equally likely to reproduce? No inheritable traits liable to move the needle one way or another?
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.
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).
Countering the nonsense prevalent in a lot of evolutionary psychology counts as a big positive in my book.
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.
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.
You can have evolution even within your own lifetime. Cancer progression, for example, is governed by selective pressures on the tumor.
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.
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
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.
Crocodiles live in the river and mate with crocodiles in the same river.
Humans live in diverse ecosystems from artic to desert to city, each with differing environmental challenges, and mate with whoever they fancy when they swipe right.
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.
>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):
[0] https://en.wikipedia.org/wiki/What_a_piece_of_work_is_a_man[1] https://en.wikipedia.org/wiki/Hanlon%27s_razor
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 !
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.
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.
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.
Why did you just assume there are genes that predict "not wanting children"? It's happening uniformly all around the world, and is much better predicted by things like wealth and freedom than anything else: cultural reasons, not heredity.
I think you've misunderstood my point. To clarify, there was strong selection pressure in the past to "make sex desirable" (and obviously I'm oversimplifying a lot here, but the premise still holds) because that was enough to ensure that passing on your genes was the result a large percentage of the time.
Now, though, birth control has broken that connection between "having sex" and "making babies", so now "making sex desirable" no longer is enough of a trigger that results in passing on your genes. So, in that sense, the environment in which humans reproduce has changed drastically, in a short period of time. So now there should be strong selection pressure for people to have children beyond just making sex enjoyable. Whether that shows up in a stronger innate desire for children themselves or whatever I won't speculate on - I'm just making the point that widespread birth control is a huge change to humans' environment to which natural selection should act on, by definition. What I am not saying is that "not wanting children" currently is the result of some fundamental genetic difference between sub-populations.
I think my point still stands? For selective pressure to select anything, there has to be preexisting genes that predict how much someone wants kids. And again, cultural and material factors are so much more important than genetic ones on the matter, that I don't believe the latter has any quantifiable effect.
It is safe to assume pretty much any proclivity has some, however minor, genetic basis. Separated twin studies have shown enough similarities in basically every aspect of personality that it's a plausible bet.
All over the world, some groups are deciding not to have kids and some are. Globally declining fertility rate says nothing about genetic proclivity to want children unless fertility rate goes to zero.
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.
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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.
>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.
Birth control is older than the Bible[1], it just wasn't as effective. Humanity as a whole was very aware how babies come to be.
Ways to have fun without coitus aren't a recent invention either.
Human reproduction and raising children is an unusually taxing, time-, and resource-intensive process, which is why we've applied our considerable intellect to plan for that since forever.
[1] https://en.wikipedia.org/wiki/History_of_birth_control
I've read that wikipedia article, and I got the impression that to say that birth control just wasn't as effective is an understatement. One more my finding: the idea of planning your family is relatively modern: Malthusians promoted it widely. It doesn't mean people were not thinking along these lines before, but our widespread understanding of how important it is is mostly a modern phenomena. Like the idea to postpone a marriage and reproduction was not very popular before modernity. We've applied our considerable intellect to invent these things and to make not so smart people to be aware of our findings, but these are very recent ideas. In agrarian world you need a lot of people to feed your armies, so any attempts at birth control would be deemed illegal, amoral or whatever. Kings and popes would do anything to stop people from slowing down their reproduction. Which they did, witch hunt clearly stated that witches are guilty of killing yet unborn babies, ie abortions.
> Malthusianism
Weren't these more about "human population planning"?
> the idea of planning your family is relatively modern
The term "family planning" is. The general concept is not, which is why we have two thousand year old papyrus talking about birth control.
Note that at no point I used the word "family" - because just our modern understanding of a family will muddy any attempt to compare to historical fact.
Involuntary reproduction has been a tiny tiny minority of births for the past few millenia at least. It happens and is awful but it should not be construed to constitute a large part of any person's ancestry.
They may be honest when they express themselves initially, but their revealed preference later ends up being very tragic. I know several women, and others who are friends of my wife, that did the "I don't want kids" routine only to realize that this was a huge mistake and enter the dating market at 37 to find nothing but a wasteland. People can pretend that their own reason can override their biological reality, but only to a point. "I don't want to have kids" means you die alone. Eventually people realize this.
So true. "No eggs" https://youtu.be/9he_ZRnZDlk
Having kids just so you won't die alone sounds tragic too.
I'm almost 40 and never wanted kids. As a kid, everyone would say things in the context of "when you have kids of your own..." and I always knew that I didn't want them.
If I lived in a world without reliable birth control, I may have ended up with kids I didn't want, but I'm lucky that I have other options.
Kids shouldn't be raised by people who don't want them, and not everyone is born with the biological drive to reproduce.
Your view that [most] people are born wanting kids may be biased from societal pressure and a historical lack of options.
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> Stop sharing your opinions. You will literally be extinct soon. Your existence doesn't matter.
What an insane take. You have no idea what that person's contributions are to this world, or how long those contributions will be relevant after they pass.
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.
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.
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.
>> 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.
Who said we stopped evolving? Evolution is slow cause we are many. Another garbage clickbait press release that butchers the science.
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.
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.
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.
I don't see how this would fix IQ decline.
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.
I think our intelligence is crucial to make sure that we won't get replaced by AI.
Yes, but we seem hell bent on creating AI that is smarter than ourselves, and putting it into embodied robotic form as well - humanoid robots, automated factories, AI driven cars and trucks, autonomous fighter planes...
With AI already able to hack into our human-written computer systems, now being trusted to write much of the new code itself(!), it certainly doesn't take a Sci-Fi fantasy to predict an AI agent wreaking major damage or taking control over some system/factory it was able to hack into, in pursuit of the goals it was given.
It really would not be surprising to discover that, even today, some vibe coded system has an unrequested backdoor built into it, that the agent thought (without malice) it might be useful to add.
Right now we truly are building paperclip maximizers. Idiot-savant RL-trained goal-seekers that we're hoping can be controlled via quaint means such as prompts and guardrails.
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?)
NLP
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.
Mmm, yes, some real parallels between Blindsight's conception of consciousness and LLM chain-of-thought reasoning.
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 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.
>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?
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.
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/
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Humans are the only mammals with genders at all. Are you confusing gender with sex?
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!
> Both are synonyms!
Not the way you're using them. Dogs and cats don't have genders, but they do have sexes.
Has that been proven?
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.)
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.
I'm not sure what you're getting at here, you seem to be repeating my point that humans are the only animals we know of with genders. Am I misunderstanding?
Direct quote:
> Humans are the only mammals with genders at all.
I'm still not following lol
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.
dang, sorry
If that's true. Why haven't we evolved into a species that doesn't harm each other or the environment?
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.
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.
Because we became an incredibly successful species doing just that.
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.
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!?!
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.
Maybe that's what Tibetans are evolving into?
That's the way evolution works - isolated sub-populations that mostly don't breed with outsiders necessarily diverge.
Of course evolution is essentially directionless, just "survival of the survivors", although over time whole ecosystems of co-evolving animals and plants will necessarily settle into dynamic "attractor states" of semi-stable co-existence, until a spanner is thrown into the works.
Because it's game-theory-optimal to kill everyone unrelated to you, but not too much.
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.
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.