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Humans haven't stopped evolving

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Re: Humans haven't stopped evolving

#121

Post by TheCoelacanth »

vitally3643 wrote: post #99
chaz6 wrote: post #93

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

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.

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.

Re: Humans haven't stopped evolving

#122

Post by hn_throwaway_99 »

thrance wrote: post #96
hn_throwaway_99 wrote: post #18

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 f…

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.

Re: Humans haven't stopped evolving

#123

Post by Grimblewald »

plastic-enjoyer wrote: post #72
Grimblewald wrote: post #67

Earlier quoted context omitted.

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…

> 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.

Re: Humans haven't stopped evolving

#124

Post by Grimblewald »

hn_throwaway_99 wrote: post #81
Grimblewald wrote: post #67

Earlier quoted context omitted.

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 i…

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.

Re: Humans haven't stopped evolving

#125

Post by nozzlegear »

inigyou wrote: post #106
nozzlegear wrote: post #98

Earlier quoted context omitted.

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?

Re: Humans haven't stopped evolving

#126

Post by nobody9999 »

HarHarVeryFunny wrote: post #105
lomlobon wrote: post #2

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.

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
[0] https://en.wikipedia.org/wiki/What_a_piece_of_work_is_a_man

[1] https://en.wikipedia.org/wiki/Hanlon%27s_razor

Re: Humans haven't stopped evolving

#127

Post by ticulatedspline »

chaz6 wrote: post #93

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.

Re: Humans haven't stopped evolving

#128

Post by lawyerdog »

serious_angel wrote: post #97
saidnooneever wrote: post #77

Earlier quoted context omitted.

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 lik…

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.

Re: Humans haven't stopped evolving

#129

Post by seanmcdirmid »

ninthcat wrote: post #115
seanmcdirmid wrote: post #104

Earlier quoted context omitted.

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.

Evolution happens even without any selection pressures, for example with genetic drift.

That requires isolated populations and we don’t really have that anymore.

Re: Humans haven't stopped evolving

#130

Post by ASalazarMX »

gweinberg wrote: post #118

"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.

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