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Lactose tolerance is a classic example of a recently evolved trait.
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
"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.
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.
Who said we stopped evolving? Evolution is slow cause we are many. Another garbage clickbait press release that butchers the science.
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.
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.
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.
There are a couple of species that remain essentially unchanged for the last couple million years. Why can't humans become one of them?
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.
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.
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.
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.
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.
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.
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.
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.
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.
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 choice for the illustration is marvelous, no words... I love it...
Thank you for mentioning the Artists of so ineffably magnificent works:
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
sure seems like a lot of 'em have
Maybe so, but can you please not post unsubstantive comments to Hacker News? We're trying for something a bit different here.
If that's true. Why haven't we evolved into a species that doesn't harm each other or the environment?
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.
Because we became an incredibly successful species doing just that.