Will humans continue to evolve?

[Tyshalle]

Just wondering what you guys think. It seems to me like evolution is being stunted by people. The primary mechanism of evolution as I understand is is that mutations that make it easier for life-forms to get eaten or otherwise killed tend to get wiped out while mutations that make it easier for life-forms to survive and reproduce live on. Well, now we live in an age when our disabled are taken care of, our retards can live to be a hundred, even people born missing limbs thrive just fine.

So are we going to continue to evolve by any traditional standard, do you think? Sure, people will have genetic mutations, but for the most part these won't prevent them from reproducing so at this point most of our mutations will live on, whether detremental to us or not. So in a million years, assuming nothing catastrophic happens like an asteroid or worldwide famine or nuclear armaggeddon, are human beings likely to look/be much different than we are now? As near as I can tell, at most we'll all be taller, and there will be rampant disabilities/diseases/et cetera kept in check by medicine and technology.

[ArmorPierce]

People currently living in first world standards are probably not going to get any taller. Natural evolution is limited currently due to human civilization cancelling out some of the normal evolutionary pressures but it is not gone completely. That said, I think for the most part we are not going to evolve any further through natural selection. If anything, since those with genetic qualities that would have been weeded out in the past continue to reproduce, that would tend to allow those qualities to be come more common.

[Forum Troll]

So in a million years, assuming nothing catastrophic happens like an asteroid or worldwide famine or nuclear armaggeddon, are human beings likely to look/be much different than we are now? As near as I can tell, at most we'll all be taller, and there will be rampant disabilities/diseases/et cetera kept in check by medicine and technology.

Short of a disaster wiping out humanity entirely, it's practically inconceivable that artificial self-improvement wouldn't occur before then. Even a mere 0.1% chance of that per century would reverse to nearly a 100% guarantee sooner or later over a span of 10000 centuries (simplistically treating as independent event probabilities, 1 - 0.999^10000 = 0.999955), and the actual likelihood of such starting even this century is vastly higher than just the preceding.

Genetic engineering, cyborgization, nanotech, transhumanism, et cetera. Short of a permanent end to technological advancement (in other words extinction), it's just a matter of time. Vastly increased intelligence and longer lifespans up towards immortality are too advantageous to not be sought by some.

Historians have observed that people sometimes overestimate change in the short-term but usually underestimate it in the long-term. A mere thousand years ago was the world of 1009 A.D., and you're talking about a million years.

[Tyshalle]

I'm just talking about the world in terms of biological evolution.

Though, I agree, we're eventually going to become so adept at genetic manipulation that we'll be able to weed out the bad traits anyway.

So I guess that means that we're mostly done with natural evolution. At this point it's more of an impediment to us than anything.

[General Zod]

People currently living in first world standards are probably not going to get any taller. Natural evolution is limited currently due to human civilization cancelling out some of the normal evolutionary pressures but it is not gone completely. That said, I think for the most part we are not going to evolve any further through natural selection. If anything, since those with genetic qualities that would have been weeded out in the past continue to reproduce, that would tend to allow those qualities to be come more common.

Evolution takes place in terms of millions of years anyway. So it's not as if evolutionary change is something you'd be likely to notice within your lifetime as it is.

[Forum Troll]

So I guess that means that we're mostly done with natural evolution. At this point it's more of an impediment to us than anything.

Yes, it operates on so slow timescales compared to technological development. Even for plant and animal life, I'd expect more new species in the long term from artificial creation than the glacial pace of natural evolution.

[Darth Ruinus]

I haven't taken a biology* class in a while but, I thought evolution was just the change in allele frequency over time, from one generation to the next. So my kids having different traits or combinations of traits is that change in allele frequency over time, hence evolution. What the OP described sounds more like natural selection, and what General Zod said is innacurate, as evolution itself doesn't take millions of years, but the development of new characteristics (longer necks, more arms, etc etc.) is what takes millions of years.

*Unless biological anthropology counts.

[General Zod]

I haven't taken a biology* class in a while but, I thought evolution was just the change in allele frequency over time, from one generation to the next. So my kids having different traits or combinations of traits is that change in allele frequency over time, hence evolution. What the OP described sounds more like natural selection, and what General Zod said is innacurate, as evolution itself doesn't take millions of years, but the development of new characteristics (longer necks, more arms, etc etc.) is what takes millions of years.

*Unless biological anthropology counts.

That's basically what I was trying to get across. That any kind of significant evolutionary change isn't something you're going to notice until millions of years have passed. We're obviously evolving, but for the most part the changes are small, minute and subtle.

[Serafina]

The whole "modern technology is stopping evolution"-stuff is crap.

Some people argue that humantiy no0 longer evolves because we no longer live in a "natural" enviorment.
But who ever said that evolution only occurs in "natural" enviorments (whatever thats supposed to be).

There are still a lot of traits that are favored and evolutionary beneficial. Physical fittness is less of a necessity: Today, you can survive with traits that would kill you without treatement, and still raise kids. You do not even need to raise your kids yourself.
However, being healthy and a good parent still increases the chance that your kids will have children on their own - thus increasing your evolutionary fittness.

People arguing that medical treatment and other modern, social benefits are undermining evolution are thinking in a black-whie scheme and are generalizing. These things may decrease the impact of genetic disadvantages, but unless they are so advanced that they eleminate all genetic differences, evolution will still occur.

Modern technology & society will change the path of human evolution (if it lasts long enough), but it will not stop it.

[Edi]

One factor that slows development leading to speciation is populations mixing so much that you don't get enough isolated pockets for a long enough time. Other kind of things that are not related to speciation are still going to happen.

[Tyshalle]

Maybe you're missing the point, Oberst. I was talking about evolution as a species. That is where genetic mutation becomes shared amongst the entire species, so that we can be identified by it. Specifically what I was talking about, though I didn't say it, was macro-evolution, by which the species will have evolved substantially enough for it to be noticable to anyone. For instance, if we all grew tails, or became purely carnivorous. Something that would evolve us beyond our homo-sapien status.

Obviously our genes will continue to mutate. However, the way things are going I seriously doubt that we're going to see any natural macro-evolution in our species even after a million years.

The key to evolution is that the weaker species becomes extinct while the stronger survive to spread their seed, which then mutates and if it mutates in a negative way it's destroyed, but if it mutates positively that trait will live on and the process continues forever. Well at this point the only mutations that get cut out are the ones that are so seriously fucked up they can't survive no matter how much medical technology we have. All the others, from retards to people born blind or without hands, well, they can all survive just fine.

The point is, we all continue to spread our seed, but there's no mechanism by which one becomes more dominant over another, so true evolution (if I understand it correctly) of the major kind just can't happen anymore.

Artificial evolution probably will, though.

[Erik von Nein]

Okay, so you're not talking about evolution but speciation. Evolution literally is just the change in gene frequencies over time. It can cause speciation or what have you, but it says nothing about whether or not it'll cause certain traits to become prevalent or whether or not there'll be a new species, or even whether or not it's something natural. The only way to completely stop evolution would be to guarantee that all gene frequency changes cease. Whether that means every single person is an exact genetic duplicate of each other or whether the children of certain parents have the exact same DNA as their parents is something else.

[Rye]

I don't see why we wouldn't continue to evolve. Assuming our technologies can keep up with our environmental issues, we're not going to change that much, except maybe have more asthmatics or short sighted people. So long as our environment remains similar and we don't end up isolating populations, you would expect our genes to stay relatively consistent.

[TheLostVikings]

Fin fact: Currently human evolution is happening at a much faster pace than it ever has in the past. A massive gene pool to select from, combined with our current globalized society where people relocate great distances is commonplace.

So no offense, but the belief that evolution has somehow slowed down is pretty much as ass backwards as you can get.

[defanatic]

Fin fact: Currently human evolution is happening at a much faster pace than it ever has in the past. A massive gene pool to select from, combined with our current globalized society where people relocate great distances is commonplace.

Doesn't a large population that continues to interbreed (facilitated by globalisation) mean that the amount of genetic drift is slowed?

Also, Firefox keeps thinking I need more 'z's in words.

[Junghalli]

Evolution is the environment killing off individuals that can't survive in it, leaving behind those that can. Humans whenever possible change our environment to suit the needs of our present form. Yes, technological society basically removes the impetus for evolution. Assuming it lasted for many millions of years, and we didn't choose to modify ourselves, I would expect us to eventually become living fossils, like the Coelacanth. Living fossils are what you get when you have a species very nearly perfectly adapted to a relatively unchanging environment. Human civilization is all about creating such an environment for us.

Realistically, we should be able to control our own evolution via genetic engineering in a few decades or centuries, and I expect artificial modification to take over from natural selection in the near future.

[Junghalli]

Fin fact: Currently human evolution is happening at a much faster pace than it ever has in the past. A massive gene pool to select from, combined with our current globalized society where people relocate great distances is commonplace.

So no offense, but the belief that evolution has somehow slowed down is pretty much as ass backwards as you can get.

But what is being selected for? Sure, mutations are still happening, but to get evolution you have to get individuals with certain traits being denied the chance to breed as much as those with other traits. In our present society, virtually everyone will get a chance to breed.

[Erik von Nein]

Evolution is the environment killing off individuals that can't survive in it, leaving behind those that can.

No, that's natural selection, a process that can drive evolution and speciation. Evolution has already been defined several times in this thread.

Humans whenever possible change our environment to suit the needs of our present form. Yes, technological society basically removes the impetus for evolution. Assuming it lasted for many millions of years, and we didn't choose to modify ourselves, I would expect us to eventually become living fossils, like the Coelacanth. Living fossils are what you get when you have a species very nearly perfectly adapted to a relatively unchanging environment. Human civilization is all about creating such an environment for us.

No species is "perfectly adapted," only well-suited for its environment. The only reason Coelacanth are around today is because nothing has killed it off. Species don't disappear when speciation happens, otherwise there wouldn't be any phylum's left, let alone domains. Human genetic variation will continue unless we, as I said above, turn every single member of our species into an exact duplicate of each other. Sexual reproduction handily takes care of cloning, even if we did start mucking about with our DNA.

[Junghalli]

No species is "perfectly adapted," only well-suited for its environment. The only reason Coelacanth are around today is because nothing has killed it off. Species don't disappear when speciation happens, otherwise there wouldn't be any phylum's left, let alone domains. Human genetic variation will continue unless we, as I said above, turn every single member of our species into an exact duplicate of each other. Sexual reproduction handily takes care of cloning, even if we did start mucking about with our DNA.

Yes, but there probably wouldn't be any major changes in our physical form, as there's no reason for them to happen. That was my point.

[Erik von Nein]

Ah, I see. It's possible there could be, but you are correct that it'd have to have some sort of driving force, like unequal reproductive success to happen in any appreciable amount of time.

[Lord of the Abyss]

Evolution is the environment killing off individuals that can't survive in it, leaving behind those that can.

Actually, evolution is due to success or failure in passing on genes, not survival. Die and pass on your genes and you are a Darwinian success; live and don't pass on your genes and you are a Darwinian failure. And the environment is actually pretty limited as a driver of evolution, because it's comparatively static; unlike living competitors/predators, it doesn't respond to adaptation with adaptation of it's own.

As for evolution stopping; there are still people who do stupid things that get them killed before they can breed. There are still people who are better at attracting the opposite sex than others. There are still fatal diseases and genetic disorders. And so on. Selection hasn't stopped.

And in practical terms, I do expect that artificial intervention will shortly become a much stronger evolutionary force than natural selection in humans. So, if anything, I expect humans to evolve much faster in the future, but according to artificial selection instead of natural selection. Which, yes, will still count as evolution, just as sexual selection counts as evolution.

[Junghalli]

Actually, evolution is due to success or failure in passing on genes, not survival. Die and pass on your genes and you are a Darwinian success; live and don't pass on your genes and you are a Darwinian failure.

Well yes, I realize I was grossly oversimplifying, but my point is an organism probably isn't going to change drastically if it has no reason to do so. Humans have little reason to change, as we use our technology to eliminate the need for environmental adaptation (which includes biological factors like predators - killing off or keeping away things that are dangerous to us with technology is one of the first things we try to do).

As for evolution stopping; there are still people who do stupid things that get them killed before they can breed. There are still people who are better at attracting the opposite sex than others. There are still fatal diseases and genetic disorders. And so on. Selection hasn't stopped.

True, but it's probably not pushing the species in any particular direction, which is what needs to happen for the species to change.

[Lord of the Abyss]

As for evolution stopping; there are still people who do stupid things that get them killed before they can breed. There are still people who are better at attracting the opposite sex than others. There are still fatal diseases and genetic disorders. And so on. Selection hasn't stopped.

True, but it's probably not pushing the species in any particular direction, which is what needs to happen for the species to change.

Disease resistance, better skills at manipulation and detecting same, and less personal aggressiveness come to mind as directions natural selection is still pushing us, I think. Disease still kills, talking your way into a woman's bed is still a good way to spread your genes, and volunteering to fight & picking fights still risks getting you killed young.

[Forum Troll]

What the OP described sounds more like natural selection, and what General Zod said is innacurate, as evolution itself doesn't take millions of years, but the development of new characteristics (longer necks, more arms, etc etc.) is what takes millions of years.

You could say there are two timescales for evolution and natural selection. It takes eons for major entirely new features to evolve (involving a long chain of the right mutations), but the relative frequency of already existing traits can change relatively fast such as in mere centuries to millennia.

Humans breeding wolves into all the different types of dogs in mere thousands of years is like the latter. Any breed of dog still has only the same basic features as any other canine, without any major new features, but they differ much in size and even in intelligence.

it'd have to have some sort of driving force, like unequal reproductive success to happen in any appreciable amount of time.

There actually is quite unequal reproductive success today. From the natural selection standpoint of which genes become more prevalent, reproductive "success" is primarily a function of somebody's number of children.

Ordinarily, we might also consider their chance of surviving to reproductive age, but, with a relatively low death rate before old age in modern society, that's very close to 100% now for anybody from an idiot to a genius. Violence kills only 0.06% of the U.S. population per year. Even car accidents only kill 0.14% of the population annually. Chances of death from such are obviously higher in event of foolish behavior, but someone is still extremely probable to reach reproductive age in all but the most extreme cases.

Who is more likely to have a large number of children and thus be more favored by natural selection now? A 130 IQ computer nerd or a 90 IQ trailer park resident? The former most likely has no more than one or two children if any at all, the latter often has several children.

A comedically exaggerated version of the future consequences of this was depicted in the film Idiocracy.

Countering that will be one of the side benefits of genetic engineering, as otherwise the species would become pretty screwed up over time as long as the modern environment was sustained.

[Junghalli]

Who is more likely to have a large number of children and thus be more favored by natural selection now? A 130 IQ computer nerd or a 90 IQ trailer park resident? The former most likely has no more than one or two children if any at all, the latter often has several children.

A comedically exaggerated version of the future consequences of this was depicted in the film Idiocracy.

Countering that will be one of the side benefits of genetic engineering, as otherwise the species would become pretty screwed up over time as long as the modern environment was sustained.

That's correlated with lower education more than anything else though, so it's very questionable whether it amounts to a meaningful genetic selection pressure. The trailer park resident in your example is probably the way he is because he grew up in a trailer park, not because he has some sort of congenital brain defect.