Researchers Say Human Brain is Still Evolving

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."

Comments

It's remarkable how wrong this is

[nokilli]

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.

Re:It's remarkable how wrong this is

[John Hawks]

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:

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

Re:It's remarkable how wrong this is

[Cruithne]

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

Re:It's remarkable how wrong this is

[Cruithne]

"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.

Re:It's remarkable how wrong this is

[justin12345]

Socialism has nothing to do with it.

I live in Brooklyn, and a nasty part of it none the less. Long story as to why I moved here...

I'm not too worried about survival (I'll be leaving this winter; moving into a .5 million dollar home in Baltimore. Plus, NYC has a very low murder rate compared to most American cites.)...

Still as far as selection goes, my neighbor is clearly the victor. Ultimately his family will in the long term have a much greater chance of survival then mine, based on shear numbers alone. He works as a janitor (kinda), makes maybe 25k-30k, but has 9 kids by three different women (8 really, the 9th is expected in December). I OTOH have none (granted he is 4 years older then me... he is 29 and unmarried, had his first child at the age of 17).

Chances are, most if not all of his children will survive to reproductive age. Its also likely that few will attend college (though this really is speculative, I'm just basing it off of the fact none of their parents or grand-parents did, AFAIK).

Chances are that I will have few or no children: My girlfriend is on the pill and another prescription medication which further limits her fertility because it would require an abortion if she were to become pregnant within a year of taking it (the medication causes severe birth defects).

Even if we do wind up reproducing, I really doubt I will have more then 2 or 3 children. My neighbor OTOH, whom definitely has a lower quality education (intelligence is too subjective to judge) has definitely been far more prolific then I will ever be, though I had and probably will have a far greater quality of life.

Ironically, because we have access to excellent health care (much more so then my neighbor) we are able to choose sterility. That is not the case for my neighbor, whom cannot/will-not control reproduction (as he has complained in his own words during our infrequent conversations).

There is no welfare involved here. All parents mentioned here work and support themselves and their children (to the best of my knowledge).

Duh?

[Dimensio]

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.

Counter-evidence...

[FyRE666]

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...

Re:The human brain...

[Jace of Fuse!]

We actually think with our stomachs.

Nope. Getting warm though. Little lower...

Depends on how much spaghetti you eat

[ScentCone]

Also, I understand that if you wear an eyepatch, that strengthens the optic nerve on one side of your brain. It is proof of His Noodly Will.

Learn the nature of science.

[Dimensio]

Now that is a loaded statement.

No, it isn't.

Evolution is nothing but a theory.

Creationists say this like it means that it's somehow on shaky ground. It isn't. "Theory" is the highest level that any explanation reaches in science. There is no higher label. The dismissing of evolution as "nothing but a theory" only demonstrates that the one making the dismissal is fundamentally ignorant of scientific terminology.

Ask any REAL biologist (like those with Ph.D.'s or those who work in colleges), and they will admit evolution is a theory.

And theories never get any higher in rank.

It is not fact.

"Facts" are simply statements about single observations, nothing more. "Facts" really don't mean anything in the long run in science.

It is not a scientific law.

And it never will be. Despite the ignorant rantings of creationists, theories do not ever become laws. Theories and laws are two different types of statements. Laws are general statements about collections of previous observations by which future observations are predicted. Theories are an attempt to explain the underlying causes of the observation. Example: the "Law of gravity" is a model of the resultant force caused by gravitational attraction between two masses. The theory of gravity -- more commonly known as "relativity theory" -- is an attempt to explain why that force occurs.

Laws are no more certain than theories. Theores do not "graduate" into laws. Laws can just as easily be falsified -- in fact, the "Law of Gravity" as we know it from Newton is false. Saying that "evolution is a theory, not a law" as if this casts some doubt on the validity of evolution again only demonstrates that you are fundamentally ignorant of how science works.

The cool thing Intelligent Design is we know God made us.

No, Intelligent Design postulates -- based upon faulty premises -- that certain features in biological systems are too "complex" to have come about through evolution, and therefore must have been "designed" by some unnamed designer. "God" doesn't enter into "Intelligent Design" as it is presented by the shysters who try to shove it into school cirriculums.

That you think that it directly refers to a god -- especially the God that you happen to worship -- only further demonstrates that ID is nothing but a sham to try to sneak religion into schools.

As for "know", I'm sorry but claiming that you "know" something isn't valid justification for scientific consideration. If you have no evidence, then you have no case.

Think about how the world was made. Science has a theory called "Big Bang". It is a theory which states that in the start the mass was so dense, it exploded and everything flew away randomly, making stars and planets, and life.

The Big Bang doesn't cover abiogenesis. Please actually learn the science behind it before attempting to discuss it.

For any people who know statistics, what is the probability of that happening? How many times would I have to flip a quarter and get heads in a row? 100,000,000,000 times? 100,000,000,000,000 times?

You know the statistical likelyhood? Please present the math. Show all of your work. If you can't then you don't have a case. Please avoid the fallacy of pointing to the "likelyhood" of the universe appearing in its exact configuration as it is and pretending that the universe couldn't have just as easily supported life had it come about in a somewhat different configuration unless you can demonstrate that it is the case.

You would have a better chance at taking a watch, hitting it with a hammer until it was broken into 1000 peices, and then putting it in a bag, shaking the bag, and having the watch come back together out of the random movements.

False analogy, demonstrating a fundamental ignorance of cosmology. Try to understand why physicists say what they say about universal origins before thinking that

Re:Theory or God??

[Wavicle]

evolution is a theory. It is not fact. It is not a scientific law.

Theory and fact are not exclusive. Stating something is a theory and is not a fact implies that the theory is wrong. Scientific laws are just "convenience" wrappers for theories. The things we call "laws" are theories just the same. They are still subject to the same rigor as theory.

The cool thing Intelligent Design is we know God made us.

And that is why you are NOT a science. Because you "know." You've moved from theory to statement of fact.

For any people who know statistics, what is the probability of that happening?

The probability of the event cannot be determined because we lack understanding of the state space.

How many times would I have to flip a quarter and get heads in a row? 100,000,000,000 times? 100,000,000,000,000 times?

The probability of getting N heads in a row is 1/(2^N). But that is irrelevant to the discussion.

You would have a better chance at taking a watch, hitting it with a hammer until it was broken into 1000 peices, and then putting it in a bag, shaking the bag, and having the watch come back together out of the random movements.

And you've calculated the probability of this how?

God made life. It is called a soul.

That it is incorrect. Life was bestowed upon the earth when the Flying Spaghetti Monster extended His noodly appendage and brought forth a midget in full pirate regalia.

I agree

[Ogemaniac]

You are absolutely right...smart people are not breeding enough in the first world. Birthrates are now below replacement levels in every advanced country, with the US being in the least-bad position. In other nations, such as Japan, the lack of children is becoming a serious political issue. It will eventually be a problem in the US as well.

In order to sustain our population (which seems a reasonable target) we need to have about 2.1 children per woman. In the US, lower class people are doing just about that. It is the top half of the income distribution that is failing to do its duty by replacing itself in the next generation.

I have seen some estimates that we could lose as much as one point of IQ per generation due to differential numbers of children and mother's age at birth - a pretty scary thought if you ask me.

Unless some amazing new technology comes to save the day, in the next few years we are seriously going to have to consider more government manipulation of birthrates, or our society and culture could disappear.