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Biotech Science

Researchers Say Human Brain is Still Evolving 923

Posted by CowboyNeal
from the smarter-better-faster dept.
Oleg Alexandrov writes "Two genes involved in determining the size of the human brain have undergone substantial evolution in the last 60,000 years, researchers say, suggesting that the brain is still undergoing rapid evolution. The discovery adds further weight to the view that human evolution is still a work in progress, since previous instances of recent genetic change have come to light in genes that defend against disease and confer the ability to digest milk in adulthood."
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Researchers Say Human Brain is Still Evolving

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  • by nokilli (759129) on Thursday September 08, 2005 @10:52PM (#13515321)
    First off, it's hard to see *any* species as being in anything other than a state of evolution. To suggest otherwise implies a superficial understand of what evolution is about.

    That being said, it's conceivable that we're at the point where the human brain is the exception to the above. After all, what has been the driving force behind the evolution of the brain? Big-brained people surviving and succeeding in reproduction where little-brained people fail.

    This isn't really happening anymore. Yes, smart people still trump over stupid people in most aspects of life, but stupid people still reproduce. Civilization has removed the engine through which drives the evolution of the species.

    I can't believe how often highly educated people will pontificate on this subject, and get it wrong. Yes, usually the media is to blame -- science reporting is notoriously bad -- but that does not appear to be the case here.

    Ironic that they should be so wrong on this of all subjects.
    --
    You didn't know. [tinyurl.com]

    • First off, it's hard to see *any* species as being in anything other than a state of evolution. To suggest otherwise implies a superficial understand of what evolution is about.

      I beg to differ. With the current state of affairs in several countries and the way people in the east are connected to what the west does, I propose that we consider not only the human brain, but the human species itself as an exception. We are undergoing convolution [wikipedia.org] instead of evolution. Besides, human evolution is not a safe s
    • by John Hawks (624818) on Thursday September 08, 2005 @11:02PM (#13515396)

      Well, it sure might look that way, but these genes strongly suggest that something related to cognition was under strong selection throughout history.

      One of the two genes, ASPM, appears to have come under selection only 5800 years ago; but it is now at around 20 percent, with a frequency of near 50 percent in some Near Eastern populations. Whatever this allele does, it had a selective advantage of more than 5 percent. They don't know it necessarily makes people smarter, but it's hard to think what else it might be.

      That's really the neat part; that it shows that this idea of "survival of the dumbest" is apparently not what has been happening. Instead, there is every reason to think we have been getting smarter.

      The submission doesn't mention the most problematic part: These alleles are high frequency in some populations, but absent or low frequency in others -- suggesting there may be adaptive differences in the brain among human populations. From my weblog post: [johnhawks.net]

      Geneticists are increasingly finding genetic variants that affect behavior. Several of these variants are now known to vary in frequency in different human populations. These alleles are two; the 7r allele of the dopamine receptor D4 (DRD4) gene is another that influences ADD/ADHD susceptibility (Harpending and Cochran 2002). The selective structure underlying DRD4 variation may be frequency-dependent, with different alleles correlating with alternative behavioral strategies that pose greater or lesser advantages in some populations. It is not clear whether such a mechanism is true of ASPM and Microcephalin; the selected alleles have risen to such high frequencies in some populations that it seems they are not mere alternatives; they are unilaterally advantageous -- at least where they have become common already.
      --John
      • One of the two genes, ASPM, appears to have come under selection only 5800 years ago; but it is now at around 20 percent, with a frequency of near 50 percent in some Near Eastern populations. Whatever this allele does, it had a selective advantage of more than 5 percent.

        It's the morning coffee gene!
      • by nokilli (759129) on Thursday September 08, 2005 @11:17PM (#13515517)
        They don't know it necessarily makes people smarter, but it's hard to think what else it might be.
        Deference to authority perhaps? The gene that enables groupthink, which, today seems to be sending us into the abyss but thousands of years ago meant the difference between one tribe surviving another?

        The whole business with the alleles and DRD4, I don't know anything about that. I just found the way that the conclusion was stated here to be clumsy. Rather than talk about the brain still evolving, a more accurate headline might be "Path of human brain's evolution identified".

        The coverage evolution has received of late has been spooky. I'm seeing all kinds of signs that the MSM is trying to accommodate "intelligent design", an agenda that is served by implying that human evolution was thought to have stopped somehow.

        Now that I'm looking at it again, maybe it is another case of bad reporting.
      • by thecampbeln (457432) on Friday September 09, 2005 @12:40AM (#13516025) Homepage
        For about the last 100 years(-ish, in the western world at least), the engine that drives the evolutionary process in the human population has been (all but) removed by way of social programs, improved medical techniques, invitro fertilization (natural selection... anyone?), you name it. That's not to say I'm advocating doing away with these things, but anything that allows for the production of offspring by individuals that otherwise would not have had the ability or made it to the age to reproduce *naturally*, is "dumbing down" our collective human gene pool.

        If nature wouldn't have allowed certain individuals to reproduce, and yet modern medicine/technology/whatever have, their "faulty" genes are allowed to continue past their naturally selected "use by date", so to speak. How in the hell is this not a bad thing for the population as a whole? By definition, natural selection has been removed and therefore evolution has ceased. Sure, the population is "evolving" (read: reproducing) but with a near 100% reproduction rate amongst those individuals who *choose* to reproduce (again, no evolution here), it is not "evolving" in the Darwinian sense. Only those with severe medical or physical problems are no longer "able" to reproduce, but again this does not evolution make (IMHO).

        • the engine that drives the evolutionary process in the human population has been (all but) removed by way of social programs, improved medical techniques, invitro fertilization (natural selection... anyone?), you name it

          No. Those things changed what would be regarded as "fitness" in that context but didn't somehow magically suspend evolution.

          If nature wouldn't have allowed certain individuals to reproduce, and yet modern medicine/technology/whatever have, their "faulty" genes are allowed to continue past

      • by ShadyG (197269) <[moc.liamg] [ta] [cisumyargb]> on Friday September 09, 2005 @01:42AM (#13516370) Homepage
        Whatever this allele does, it had a selective advantage of more than 5 percent. They don't know it necessarily makes people smarter, but it's hard to think what else it might be.

        That's because you don't have it.
    • by Cruithne (658153) on Thursday September 08, 2005 @11:23PM (#13515557)
      The solution to this problem is obvious.... only let the people with an IQ above X have sex :D

      If you mod me down or reply negatively, you lose sex priveledges too :D
      • Cute little joke, but eugenics is a debunked pseudo-science. It did not produce supermen or a master race in 19th century America, or The Third Reich. Two idiots can produce a genius child. Two geniuses can produce an idiot child. Two parents born blind can produce sighted children. An athlete and a model, seemingly superior breeding stock, frequently have children with horrible birth defects.
        • by JeffSh (71237) <jeffslashdot@@@m0m0...org> on Friday September 09, 2005 @12:06AM (#13515830)
          Eugenics was only a single generation (or perhaps 2 generations) of testing. breeding favorable traits (or any trait) requires many many generations.

          to see this, just look at dog breeds.

          the same could easily be done with humans, certainly.
        • by Cruithne (658153) on Friday September 09, 2005 @12:06AM (#13515832)
          "An athlete and a model, seemingly superior breeding stock, frequently have children with horrible birth defects."

          I like how that's totally a fact you can back up with data from the local library's copy of "kids of athletes and models - 2005 edition".

          But seriously, although eugenics does not sit well with me or anyone most likely, and while your logic is correct - two idiots can breed a genius, I would wager statistics would prove that people with higher educations breed people who contribute more to society, and it probably helps to be more "well off", too.

          Before I get flamed to death, I am definitely not advocating birth control in this sense (or eugenics) - the key is in the education, which brings with it the wealth.

          To me its always been a shame that one of the most promising tools for improving society gets the shaft over and over again... Not to get offtopic, but its a shame that probably more than half the teachers in our institutions should not be teachers, and that the ones who should teach out of a desire to teach and make a difference (rather than for the small compensation) - most everyone has that really good teacher they remember that really made a difference.

          To be a teacher should require as much education as it does to become a Doctor - possibly more, and they should be paid more, too. The day we see that is the day we see some real advances in society.
          • diversity means strength as a whole. it's completely stupid to want all people to be "ubermensch".

            if i had time to write a long reply, i'd argue that it is in fact the presence of the "weaker" that allows for a humankind which is strong and adaptive as a whole.

            to put it simply: if we were all rocket scientists, the world would be quite a messy place :-)
        • by aussie_a (778472) on Friday September 09, 2005 @12:08AM (#13515840) Journal
          An athlete and a model, seemingly superior breeding stock, frequently have children with horrible birth defects.

          Which goes to show they aren't superior breeding stock. It was probably the bulemia and drugs that caused the problems.
    • by exp(pi*sqrt(163)) (613870) on Thursday September 08, 2005 @11:26PM (#13515580) Journal
      You're as wrong as the people you criticize
      Civilization has removed the engine through which drives the evolution of the species.
      What engine has been removed? There is still a differential rate of reproduction between different groups and so natural selection is carrying on exactly like it has always done. You say the engine has been removed because you have a preconceived notion that certain traits should be selected for (eg. not being stupid) and when you see that those are not the traits associated with a higher differential rate of reproduction you dismiss it as not being evolution. Sometimes I wonder if anyone out there has actually bothered to try understanding evolution.
  • Duh? (Score:5, Insightful)

    by Dimensio (311070) <darkstar@@@iglou...com> on Thursday September 08, 2005 @10:54PM (#13515333)
    Evolution is not attempting to attain a certain "goal" at which it stops. Evolution is simply the result of certain genetic traits being selected based upon environmental pressures. It shouldn't be too surprising that evolution still occurs in humans so long as there is a situation where some genetic traits are more likely to be passed on through reproduction than others.

    I guess this could be news to people who don't actually understand evolution -- which, given the popularity of pseudoscience like "Intelligent Design" and non-science like "Creation Science" -- probably is quite a bit. Unfortunately, experience shows that they don't really care to learn anything about evolution anyway, so chances are they'll do little but mock the findings without even trying to understand them.
    • Re:Duh? (Score:3, Insightful)

      by gad_zuki! (70830)
      > Evolution is simply the result of certain genetic traits being selected based upon environmental pressures.

      The scope of this article is over 60,000 years, the headline suggests the brain is "still" evolving. When you consider modern medicine and modern living the most basic mechanics of evolution (natural selection) aren't nearly as powerful as they were in hunter/gatherer societies.

      So, it is news, and whats even more misleading is that the suggestion that evolution is happening due to environmental fa
  • by FyRE666 (263011) * on Thursday September 08, 2005 @10:55PM (#13515341) Homepage
    Researchers Say Human Brain is Still Evolving

    I guess these guys have never browsed Slashdot at -1 then... And how do they explain George Bush, Beanie Babies and the Crazy Frog? And where did they get a 60,000 year old brain from to find these genes - Joan Rivers' skull? No no no, none of this is adding up...
  • by sigmaseven (906671) on Thursday September 08, 2005 @10:56PM (#13515346)
    Any chance of speeding up the process before the 2008 elections?

    /in Kansas, so it might not even apply, anyhow
  • This is news? (Score:3, Interesting)

    by HisMother (413313) on Thursday September 08, 2005 @10:59PM (#13515366)

    Every living thing is evolving. No creatures alive are genetically identical to ones living 60,000 years ago. At that time there were wooly mammoths, and saber-tooth tigers running around.

    I suppose you could argue that this is useful ammo against the ID folks, but it's really only the Flying Spaghetti Monster acolytes and other True Believers who have the hubris to believe Homo Sapiens Sapiens is the pinnacle of creation, out of the box.

  • by myowntrueself (607117) on Thursday September 08, 2005 @10:59PM (#13515370)
    is an organ for cooling the blood.

    We actually think with our stomachs.

    Obviously the cooling needs of the human body are still increasing over time. Probably linked to global warming.
  • by rasafras (637995) <tamas@pha.[ ].edu ['jhu' in gap]> on Thursday September 08, 2005 @11:00PM (#13515380) Homepage
    The world has changed a lot, and I mean a lot, in the past millenium (even 2-300 years). The selective pressures that were around previously, causing the stupid to die, are no longer present. In fact, there is very little selective pressure in today's society, where the number of offspring you have is rarely related to prosperity or the like. The death rate is so low that I can hardly imagine selective forces having a large effect on evolution. Random mutation still occurs, of course, and perhaps over the next millenium one society will evolve to be smarter and will destroy the other with superior technology, but I seriously doubt this. I'm one of those people that considers human evolution to be nearly frozen. Soon to be supplanted by willful manipulation, of course (ethics debate about this some other time).
    • by Nefarious Wheel (628136) on Thursday September 08, 2005 @11:20PM (#13515540) Journal
      It's very clear that we're selecting for the ability to produce money, read the correct magazines, and our inability to spot prophylactics in the wild. And drive cars with large integral flat surfaces.
    • by craXORjack (726120) on Thursday September 08, 2005 @11:47PM (#13515720)
      In fact, there is very little selective pressure in today's society, where the number of offspring you have is rarely related to prosperity or the like.

      While I agree that human engineering will likely eclipse natural selection in the near future, I have to say that from my observations, at least of modern industrialized society, that the number of offspring is still related to prosperity. However the relation is probably backward from what you were thinking. It seems that the poorest (and least educated so maybe that is the deciding factor) members of our society are the ones having children at the youngest ages and having more children over their lifetime.

    • Nope. (Score:3, Informative)

      by aussersterne (212916)
      Ever have sex with someone of the opposite gender? Were you attracted to them? For whatever reason? And they you?

      Yes?

      Congratulations, you just participated in the ongoing process of natural selection. You yourself have applied selective pressure in favor of whatever it was that attracted you to him/her, regardless of what the nature of the attraction was or whether you can even spell it out.

      Multiply by six billion and you have the human race... evolving.
  • Gene distribution (Score:5, Insightful)

    by Fox_1 (128616) on Thursday September 08, 2005 @11:04PM (#13515414)
    Dr. Lahn said there may be a dozen or so genes that affect the size of the brain, each making a small difference yet one that can be acted on by natural selection. "It's likely that different populations would have a different make-up of these genes, so it may all come out in the wash," he said. In other words, East Asians and Africans probably have other brain enhancing alleles, not yet discovered, that have spread to high frequency in their populations.

    Another geneticist, David Goldstein of Duke University, said the new results were interesting but that "it is a real stretch to argue for example that microcephalin is under selection and that that selection must be related to brain size or cognitive function."

    Basically this study shows that the 2 genes they studied are distributed with different frequencies in different populations, but occur more often in these populations now then 60,000 years ago. Anything else is just theory and speculation.
    • Re:Gene distribution (Score:4, Informative)

      by Michael Woodhams (112247) on Thursday September 08, 2005 @11:58PM (#13515793) Journal
      There are statistical tests for the "under selection" part. here's [wsu.edu] the first summary I found. It changes the frequencies of nearby neutral mutations which get to "ride the coat-tails" of the advantageous mutation.

      The "related to brain size/function" is somewhat speculative, in that the gene could have additional unknown functions.

      That the mutation makes us smarter is much more speculative. (Indeed, I don't think the paper's authors went this far.) It could, for example, make us 0.1% less smart, but reduce the brain's metabolic cost by 0.5%.

      (Note: I've only read the linked article, not the scientific paper.)

  • by ScentCone (795499) on Thursday September 08, 2005 @11:05PM (#13515427)
    Also, I understand that if you wear an eyepatch [venganza.org], that strengthens the optic nerve on one side of your brain. It is proof of His Noodly Will.
  • Stands to reason (Score:5, Interesting)

    by Bogtha (906264) on Thursday September 08, 2005 @11:09PM (#13515455)

    Society has changed immensely over the past few thousand years. Evolutionary pressure has changed because the skills required to reproduce successfully are different. Being a good hunter is no longer a core skill. Being able to read and write is.

    I wonder to what extent the difference in population growth for various countries will influence this. At the moment, first-world countries have much lower reproductive rates than third-world countries, but if the HIV epidemic continues, that situation could reverse itself.

  • Interesting (Score:3, Interesting)

    by MattW (97290) <matt@ender.com> on Thursday September 08, 2005 @11:11PM (#13515470) Homepage
    I wonder how long it would take us to devolve via natural selection. Since there is an inverse relationship between education level and child rearing [geographyjim.org], then if one assumes more intelligent people tend to have higher educations and that higher intelligence when breeding contributes to intellectual evolution, then we may well be devolving because stupid people disproportionately reproduce. Of course, we'll probably genetically engineer our own brainpower up before too long, and solve that problem while opening up a whole new can of worms.
    • Re:Interesting (Score:5, Interesting)

      by king-manic (409855) on Friday September 09, 2005 @01:23AM (#13516260)
      I wonder how long it would take us to devolve via natural selection. Since there is an inverse relationship between education level and child rearing, then if one assumes more intelligent people tend to have higher educations and that higher intelligence when breeding contributes to intellectual evolution, then we may well be devolving because stupid people disproportionately reproduce. Of course, we'll probably genetically engineer our own brainpower up before too long, and solve that problem while opening up a whole new can of worms.

      This is untrue, more intelligent people have fewer children, but these children almost always survive to reproductive age. It's simply a diffeerent strategy. one economic echulon (my spelling sucks) goes for a many children, few survivors method. whiel another goes for few children, but immense resources put into each.
  • "Smart Jews" (Score:3, Informative)

    by Tablizer (95088) on Thursday September 08, 2005 @11:14PM (#13515493) Homepage Journal
    A related and interesting article on "Smart Jews"

    http://www.economist.com/science/displaystory.cfm? story_id=4032638 [economist.com]

    It seems that discrimination in Europe may have led to higher intelligence.
               
    • It's more likely that the requirement for most jewish boys to read hebrew at the age of 13(bar mitzvah?) lead to their increased empoloyment in clerical jobs, as most if not all were taught to read and write in their native language as well.

      This was at a time when most people could not read or write. Hence the average jewish male was much more eligable for employment in a clerical position than the average male in the population as a whole.

      The higher salaries conferred in clerical positions leads in turn to
  • by randumspin (902235) on Thursday September 08, 2005 @11:25PM (#13515572)
    Creatures from Another world? The past? The present?

    Why yes. Take a look over there. Its the horseshoe crab, one of natures "living fossils". Even if you don't have a saltwater reef aquarium, you may notices roaches in your friends apartment...perhaps a sign that he doesn't clean up well enough or perhaps a sign that life will persist.

    Evolution occurs as long as it is beneficial, to the organism in question or to its general environment. The oceans haven't presented enough of a change from way back when for the horseshoe crab and many other species to modify its design. Similarly, cockroaches are pretty good at finding corners and crevices to hide in and scavange, thus they have not needed change their modus operandi or physical design.

    Humans are in an entirely different environment. In fact it is said that we are the only species which controls and modifies their environment. As such, it is a natural conclusion that as long as the environment and conditions are variable, evolution will continue to progress...always looking for that perfect design for life that maximizes its ability to persist.

  • by tji (74570) on Thursday September 08, 2005 @11:38PM (#13515670)
    As others mentioned, half of the evolution process is missing.. there is no selection of better traits. Everyone lives, thrives, and reproduces regardless of their genetic adaptations (or quality).

    So, we still have the genetic randomization going on, resulting in differences in humans. But, then what happens? All the strains of humans just keep going.

    Does this result in the spectrum of humans spreading increasingly wider, so eventually subjects at two extremes barely resemble the same species?

    Will any noticeable branching happen? In previous evolution, one group survived and thrived, replacing members without an adaptation. Now, since the others still survive, and the difference between the weak and strong won't result in a dramatic difference in results for either group. Probably not anything recognizable outside the normal differences between tall & short, thin & fat, smart & dumb.
  • by adolfojp (730818) on Friday September 09, 2005 @12:08AM (#13515839)
    There can be no evolution without natural selection. We have tampered with natural selection.

    Technology has given people with hereditary conditions like diabetes and nearsightedness the same chance to pass its genes to the next generation.

    We are a weaker race because of it. Not that I am complaining ;-)

    Cheers,
    Adolfo
  • by M3number3 (814865) on Friday September 09, 2005 @12:12AM (#13515872)
    What exactly the role of modern medicine and civilization will eventually have on the overall evolution humans. Others have speculated about aspects of this, but my curiosity revolves around whether or not we (as a species) are preventing our own evolution by treating genetic diseases. Evolution is always triggered by a genetic change - with changes which make the species stronger carrying on and those which weaken the species eventually being eliminated. So what happens when a child is born with a genetic "defect" which, for lack of a better term, we simply don't understand. Do we treat that child, do we actively affect his/her ability to develop and thus prevent the eventual forking of the human species? This is somewhat thought provoking because I don't think any of us are smart enough to know the answer. The flip side of this argument, of course, is what to do when we are able to purposely engineer a superior branch of the human species. I'm not talking about changing eye or hair color, but rather our ability to create a "super human". Lastly, many folks believe that while human evolution may have slowed, it will likely make its presence known in a more significant way once we establish colonies in space. Imagine not the 1st or 2nd generations conceived and born in zero or reduced gravity (such as that in a space station, deep space craft, or even on Mars), but rather the 100th or even 1000th generation. Surely at some point these "humans" will have evovled traits which enhance their ability to survive and thrive in this new environment. Interesting stuff for sure.
  • No kidding... (Score:3, Interesting)

    by Hosiah (849792) on Friday September 09, 2005 @01:25AM (#13516274)
    I had a suspicion that the human brain was still evolving the whole time...when I noticed that it was obviously considered by nature to be optional equipment on some people.

    But seriously, we have room to grow for a reason that we never had before: Caesarean births. Now that we have the technology, the circumference of the human skull is no longer constrained to the diameter of the birth canal. Note how earlier people valued wide-hipped women for their child-producing ability, and how today, popular culture values only women with skeletal stork's bodies...a subconcious acknowledgement that natural birth is no longer a factor in evolutionary development.

  • Life on Earth has :

    Existed in its present form since the dawn of time : 42%
    Evolved over time : 48%
            Guided by a supremem being : 18%
            Guided by natural selection : 26%
            Don't know : 4%
    Don't know : 10%

    http://people-press.org/reports/display.php3?Repor tID=254 [people-press.org]

    Results for this survey are based on telephone interviews conducted under the direction of Princeton Survey Research Associates International among a nationwide sample of 2,000 adults, 18 years of age or older, from July 7-17, 2005. For results based on the total sample, one can say with 95% confidence that the error attributable to sampling is plus or minus 2.5 percentage points. For results based on Form 1 (N=1,000) or Form 2 (N=1,000) only, the error attributable to sampling is plus or minus 3.5 percentage points.
  • Duh! (Score:3, Funny)

    by ZeroConcept (196261) on Friday September 09, 2005 @10:31AM (#13518567)
    Christian researchers corrected:

    "Researchers Say Human Brain is Still being intelligently designed."
  • by kabocox (199019) on Friday September 09, 2005 @10:45AM (#13518674)
    I hate to break it to all my fellow slashdotters, but a BS, MS, or PHD doesn't make you more intelligent than a HS dropout that works as an McDonald's Manager making 30-40K and has 4-5 kids.

    Evolution is a process. It doesn't freaking select anything! ID may freaking select something. You have to prove an enity of actually meddling with humanity though to bring up ID though. We could invent some AI that lives in nano-bio-virsus that we inject into everyone and it subtly could control us or aliens could be meddling with us. When God decides to let the basic rules decide it is evolution.

    I'd be curious about how humanity has evolved in the last 3000 years. Attendance at educational environments beyond HS or middle school do not show that US humans have evolved to be smarter than those that don't have that educational system in place.

    What it does show is that those in attendance to any educational environments beyond HS produce vastly reduced numbers of offspring than those that didn't attend these environments. Attendance at an educational institution has no relation to an individual's intelligence.

    What would be interesting is seeing a graphs of occupation and/or income vs number of childern. Hint: those that have less than 2 children are being selected against. Heck, put one up showing different religions vs number of childern or even number of toliets vs number of childern that would trully show a family stress level.

    Evolution doesn't even care about numbers though. As long as we muddle through and reproduce and survive that's all that is needed.

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