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Are humans still evolving?

by MathJakob
Tags: evolving, humans
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MathJakob
#1
Jan21-14, 03:27 PM
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I've been thinking about evolution and why it may or may not have stopped. I wanted to ask here if humans are still evolving, will we ever stop? Now obviously I don't expect us to start growing a 6th toe simply because we don't need a 6th toe but in terms of intelligence?

As mankind learns more and more about the universe, we're trying to cram in more and more complex things and that got me thinking... As long as humans keep learning, will the brain become more powerful in terms of computational speeds, abstract thinking, memory and analytical thinking etc.

I think it's safe to say that mankind is more intelligent now than it was 500 years ago but is this purely because of science or has our brain evolved / adapted to understand more complex things? For example in another 100 years could we expect calculus to be taught in school to 13 year olds?

I'm not sure if this is the correct way to view it but as it stands string theory is kind of at the forefront of physics and students only start to learn it once they've covered all the previous topics by which time they're about 28 years old?

So imagine if 20 years later someone discovers some other type of theory. Now a student has to learn all the previous stuff and string theory before they can understand the newest theory. It just seems like soon humans will spend half their life studying in order to understand the latest theory?

So basically what I'm asking is will this growth in learning cause human brains to evolve so they can learn the material faster? I assume that in 100 years we will know so much more about the universe that kids wanting to learn that new stuff will have to learn calculus at 13, QM at 16, string theory at 18 etc.

How will human brains respond to the ever growing complex and "unnatural" thinking? I think there was a quote from Richard Feynman that said "If you think you understand quantum mechanics, you don't understand quantum mechanics." lol so our brains are not wired to understand these topics naturally, but hopefully in the future it will come intuitively like algebra?
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Pythagorean
#2
Jan21-14, 03:45 PM
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http://www.physicsforums.com/showthread.php?t=7521

http://www.physicsforums.com/showthread.php?t=15435

http://www.physicsforums.com/showthread.php?t=15435

also, one of the questions from the pinned post at the top of the forum is relevant:

There are certain conditions that must be met for evolution to stop, this is described by the Hardy-Weinberg Principle;
1) A population must be large
2) No mutations may occur
3) Mating must be random
4) No migration
5) No differential reproductive success

Suffice to say humanity has not met these conditions. There are also good examples of recent human evolution such as selection for CRR-Delta32 mutations during the Black Death in Europe, these mutations grant some Europeans higher resistance against diseases like smallpox and HIV
http://www.physicsforums.com/showthread.php?t=543950
Ryan_m_b
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Jan23-14, 04:03 AM
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Quote Quote by MathJakob View Post
I've been thinking about evolution and why it may or may not have stopped. I wanted to ask here if humans are still evolving, will we ever stop? Now obviously I don't expect us to start growing a 6th toe simply because we don't need a 6th toe but in terms of intelligence?

[...]

So basically what I'm asking is will this growth in learning cause human brains to evolve so they can learn the material faster? I assume that in 100 years we will know so much more about the universe that kids wanting to learn that new stuff will have to learn calculus at 13, QM at 16, string theory at 18 etc.

How will human brains respond to the ever growing complex and "unnatural" thinking? I think there was a quote from Richard Feynman that said "If you think you understand quantum mechanics, you don't understand quantum mechanics." lol so our brains are not wired to understand these topics naturally, but hopefully in the future it will come intuitively like algebra?
Unlikely. The key thing to always remember about evolution is that it is driven by reproduction. Even if being able to intuitively learn algabra/quantum physics/calculus was strongly hereditary if this trait does not allow you to reproduce more (either through higher survival chance or sexual selection) relative to others then it is not a fit trait by evolutionary standards and is just as likely to die out as spread.

vadslram
#4
Jan23-14, 08:59 AM
P: 45
Are humans still evolving?

I would say we are. But with some unique drivers. Usually evolution is driven by beneficial mutations. But with all of the technology we have survival isn't the driver it used to be. Modern medicine has allowed the continuation of genes that would have been winnowed if left alone.
Traits that don't neccesarily enhance survival have become acceptable and even prefered. Women's proportions that are so extreme as to make childbirth problematic are prized and medicine has made death in childbirth almost unheard of.
Monique
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Jan23-14, 12:14 PM
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Quote Quote by Ryan_m_b View Post
Unlikely. The key thing to always remember about evolution is that it is driven by reproduction. Even if being able to intuitively learn algabra/quantum physics/calculus was strongly hereditary if this trait does not allow you to reproduce more (either through higher survival chance or sexual selection) relative to others then it is not a fit trait by evolutionary standards and is just as likely to die out as spread.
Actually educated people reproduce less and at a later point in life, this would actually select against brainy career-driven people.
glowell55
#6
Jan24-14, 10:40 PM
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I don't think we are, in the sense that we are 'climbing' an evolutionary ladder, as they used to tell us in school.

If we are shaped by our environments (physical, social, etc), then we stopped 'natural' evolution the very moment we started putting up walls between us and nature. Growing our on food, comfortable housing, clothing, medicine. We made the environments which shape us 'easy' and perhaps sent us on a simplifying rather than trying, path. If we did not 're-org' those paths to death every few years, perhaps that would be the perfect way to start. But I am unconvinced that we are wise enough to take over the shaping of our collective evolutions, being a sub-set of the set if for no other reason, though can offer no alternative.

Foundations being so important; when we began building our forests, plains, and food to order, we basically reset all the benchmarks with no recognition. I don't know. I don't see how a 'good' kind of evolution could come out of the 'average' crowded urban environment, whether it takes 10 or 1000 generations to make profound changes for the better or worse.

I think we are getting more complicated, intellectually, because of our relatively chaotic constructions, but if we are our own measure, then there is no one to say we could or should be doing otherwise. I'm just not sure 'complicated' is always the same as 'smarter'.
Evo
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Jan25-14, 12:20 AM
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Quote Quote by glowell55 View Post
I don't think we are, in the sense that we are 'climbing' an evolutionary ladder, as they used to tell us in school.
This is so very wrong, not saying you personally believe this, but that a lot of people do. Evolution isn't about advancing, it's about changes. The changes can be considered good or bad, depending on if they are successful. Successful doesn't mean they are more advanced, just that they can survive. A trait that is advantageous today can become a disadvantage tomorrow.

As you pointed out humans are able to control, for a large part, their environment, meaning that there is less pressure to select for those that are physically or mentally fit. Modern medicine allows individuals that would normally die or have never been born to live and reproduce. We are, due to these facts, changing humans from how they would normally "evolve".
glowell55
#8
Jan25-14, 01:18 AM
P: 2
Thanks for the reply.

We are on the same page, I was just trying to differentiate and so avoid stepping on toes of alternative points of view. I posted something somewhere once which was pretty clear, wish I'd taken a picture.

However;

As you pointed out humans are able to control, for a large part, their environment, meaning that there is less pressure to select for those that are physically or mentally fit.
We kind of diverge here, if this is where you intended to end the thought, and not just stopped for investment's sake of course. I think there is more to it than selection, that it's more of a molding process; the environment applies pressure and the organism counter responds with a behavior or combined group of behaviors to that pressure, physically as well as socially. Don't mean to appear as if I am nit-picking, as I do not intend to be.
What I do mean to say is that I think we are not simply removing barriers to natural selection -- which would seem to be a bucket of very special rewards all in and of itself, but that we are actually molding a new kind of person. Maybe one that's better. If there's anything more subjective than that thought, let me know. But the point here, is a 'new' kind of person without those aforementioned selective limitations.

As an example, pit-bulls, does not have to be people. 20 centuries of breeding has sure put them in the daily news. Now they in a pack, could possibly survive in the wild, but so many other bred dogs need help just to safely procreate much less have a chance of providing for themselves that the analogy to the human breeding equivalent sure raises its head.
We have been breeding ourselves, not another way to put it, through a modified environment, and then either unconsciously or at least certainly with little care letting 'evolution' take care of the rest.

So, fact is you use far less words to get your point across, at least I got it, while remaining unsure that I've been clear enough for me, much less another.
Ygggdrasil
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Jan26-14, 01:18 PM
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Quote Quote by glowell55 View Post
We kind of diverge here, if this is where you intended to end the thought, and not just stopped for investment's sake of course. I think there is more to it than selection, that it's more of a molding process; the environment applies pressure and the organism counter responds with a behavior or combined group of behaviors to that pressure, physically as well as socially. Don't mean to appear as if I am nit-picking, as I do not intend to be.
What I do mean to say is that I think we are not simply removing barriers to natural selection -- which would seem to be a bucket of very special rewards all in and of itself, but that we are actually molding a new kind of person. Maybe one that's better. If there's anything more subjective than that thought, let me know. But the point here, is a 'new' kind of person without those aforementioned selective limitations.
I agree with you here. Because natural selection occurs, in part, by how well adapted individuals are to their environment and because humans can change their environment, humans are essentially affecting the path of their own evolution. A good example of this is the evolution of lactase persistence in ancient Europe. Humans began domesticating animals (such as cows) and as a result, those individuals who retained the enzymes to digest lactose into adulthood (enabling those individuals to consume animal milk throughout their lives) had an advantage.

Of course, many of the environmental changes (modern medicine, advantages to those who understand physics) discussed here and in similar threads are too recent to have had any appreciable effect on human evolution yet (we also recently had a very long discussion of the extent to which the ability to learn physics is genetically determined). It is worth noting, however, that technology could potentially have dramatic effects on human population genetics in the relative near term. While natural evolution occurs over long time scales, artificial selection can occur much more quickly. Technologies are already being developed that allow for preimplantation genetic screening of embryos, allowing parents to choose particular traits for their children. It is also plausible that technologies to enable the engineering of specific traits into embryos will be available within our lifetimes (we can already engineer embryos, but the technologies are not yet very efficient or safe, and in most cases we lack the knowledge of how to engineer most traits). The widespread adoption of such technologies could significantly change the human genome over a relatively short timescale.
Evo
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Jan26-14, 02:44 PM
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Quote Quote by Ygggdrasil View Post
I agree with you here. Because natural selection occurs, in part, by how well adapted individuals are to their environment and because humans can change their environment, humans are essentially affecting the path of their own evolution.
That's what I was saying.

What are your thoughts on the effects of how widespread humans have become due to migration? We have some fairly isolated pockets of humans and some areas with more population change. These sets usually have a lot of difference between how much control they have over their environment and medical intervention.
Ygggdrasil
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Jan26-14, 10:20 PM
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Yes, there are examples of isolated pockets of humans evolving specific adaptations to their environments. The first example that pops into my mind are populations in Tibet that have evolved to deal with life at high altitude (see Yi et al. 2010. Sequencing of 50 Human Exomes Reveals Adaptation to High Altitude. Science 329:75 doi:10.1126/science.1190371). Many of the changes observed in that study are thought to have evolved only 3,000 years ago. The following NY Times article discusses other recent cases of human evolution, many of which are prevalent in only certain regions of the world: http://www.nytimes.com/2010/07/20/sc...dapt.html?_r=0

Of course, the rate at which new mutations get fixed in populations (i.e. spread to become prevalent) depends not only on the magnitude of selective advantage, but also the effective populations size throughout which the mutation must spread. Modern technologies that allow humans from all areas of the globe to intermingle increases the effective populations size so whereas beneficial mutations could arise and become fixed over (geologically) short time spans in small, isolated populations, new mutations will become fixed at much reduced rates as human populations become less isolated from each other. Furthermore, since this population now lives across multiple environments, mutations that confer a selective advantage in one environment may not have such a strong advantage over the entire population, meaning the selective advantage of any new beneficial mutations that arise will also be reduced. Overall, this predicts that it will now be harder for human evolution to occur than in the past. In a previous thread, I discussed situations where we might expect human evolution to occur at a faster rate.
Evo
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Jan26-14, 10:27 PM
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Quote Quote by Ygggdrasil View Post
Yes, there are examples of isolated pockets of humans evolving specific adaptations to their environments. The first example that pops into my mind are populations in Tibet that have evolved to deal with life at high altitude (see Yi et al. 2010. Sequencing of 50 Human Exomes Reveals Adaptation to High Altitude. Science 329:75 doi:10.1126/science.1190371). Many of the changes observed in that study are thought to have evolved only 3,000 years ago. The following NY Times article discusses other recent cases of human evolution, many of which are prevalent in only certain regions of the world: http://www.nytimes.com/2010/07/20/sc...dapt.html?_r=0
Thank you, very interesting!
Sarpedon
#13
Mar14-14, 10:27 AM
P: 7
A lot of things are happening. But the main thing to remember is that humans are still reproducing and the human genome isn't fixed at all.

Most important thing is globalization. Ethnicity that were created by separation of gene pools are now being mixed again. Also, in the west people are getting less children. And in the west, educated people are getting less children than uneducated people.

Still a bit of a pressure from diseases, but nothing as big as in the past where everyone would either be resistant against smallpox to some degree or just straight out dead(unless they lived in the new world before Cortes).

Anyway, the question to ask yourself is; what genes prevent people from reproducing? Those genes are weeded out. If a certain 'stupidity'-gene (if such a thing existed) were to prevent reproduction, then yes people would get 'smarter'. So no, no genetic pressure anywhere to make people evolve to learn QM at 16 unless someone starts killing off everyone that doesn't learn QM before 16 (and they might have reproduced by then anyway).


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