Human brain still evolving!

[GrandMasterTerwynn]

In case it wasn't obvious.

Study Suggests Human Brains Still Evolving
By The Associated Press

posted: 08 September 2005
10:13 pm ET

WASHINGTON (AP) -- The human brain may still be evolving. So suggests new research that tracked changes in two genes thought to help regulate brain growth, changes that appeared well after the rise of modern humans 200,000 years ago.

That the defining feature of humans -- our large brains -- continued to evolve as recently as 5,800 years ago, and may be doing so today, promises to surprise the average person, if not biologists.

"We, including scientists, have considered ourselves as sort of the pinnacle of evolution,'' noted lead researcher Bruce Lahn, a University of Chicago geneticist whose studies appear in Friday's edition of the journal Science.

"There's a sense we as humans have kind of peaked,'' agreed Greg Wray, director of Duke University's Center for Evolutionary Genomics. "A different way to look at is it's almost impossible for evolution not to happen.''

Still, the findings also are controversial, because it's far from clear what effect the genetic changes had or if they arose when Lahn's "molecular clock'' suggests -- at roughly the same time period as some cultural achievements, including written language and the development of cities.

Lahn and colleagues examined two genes, named microcephalin and ASPM, that are connected to brain size. If those genes don't work, babies are born with severely small brains, called microcephaly.

Using DNA samples from ethnically diverse populations, they identified a collection of variations in each gene that occurred with unusually high frequency. In fact, the variations were so common they couldn't be accidental mutations but instead were probably due to natural selection, where genetic changes that are favorable to a species quickly gain a foothold and begin to spread, the researchers report.

Lahn offers an analogy: Medieval monks would copy manuscripts and each copy would inevitably contain errors -- accidental mutations. Years later, a ruler declares one of those copies the definitive manuscript, and a rush is on to make many copies of that version -- so whatever changes from the original are in this presumed important copy become widely disseminated.

Scientists attempt to date genetic changes by tracing back to such spread, using a statistical model that assumes genes have a certain mutation rate over time.

For the microcephalin gene, the variation arose about 37,000 years ago, about the time period when art, music and tool-making were emerging, Lahn said. For ASPM, the variation arose about 5,800 years ago, roughly correlating with the development of written language, spread of agriculture and development of cities, he said.

"The genetic evolution of humans in the very recent past might in some ways be linked to the cultural evolution,'' he said.

Other scientists urge great caution in interpreting the research.

That the genetic changes have anything to do with brain size or intelligence "is totally unproven and potentially dangerous territory to get into with such sketchy data,'' stressed Dr. Francis Collins, director of the National Human Genome Research Institute.

Aside from not knowing what the gene variants actually do, no one knows how precise the model Lahn used to date them is, Collins added.

Lahn's own calculations acknowledge that the microcephalin variant could have arisen anywhere from 14,000 to 60,000 years ago, and that the uncertainty about the ASPM variant ranged from 500 to 14,000 years ago.

Those criticisms are particularly important, Collins said, because Lahn's testing did find geographic differences in populations harboring the gene variants today. They were less common in sub-Saharan African populations, for example.

That does not mean one population is smarter than another, Lahn and other scientists stressed, noting that numerous other genes are key to brain development.

"There's just no correlation,'' said Duke's Wray, calling education and other environmental factors more important for intelligence than DNA anyway.

The work was funded by the Howard Hughes Medical Institute.

[Darth Servo]

I would HOPE its still evolving, given how may stupid people there still are in the world.

[Stormin]

Why would anyone who wasn't completely ignorant be surprised by this? There is no actual end to evolution, no set goal. Just constant adaptation.

[kaikatsu]

I would HOPE its still evolving, given how may stupid people there still are in the world.

But haven't you noticed stupid people tend to breed even MORE? I've often wondered if intelligence had some kind of evolutionary selection against it...

[FedRebel]

WASHINGTON (AP) -- The human brain may still be evolving.

Why would it stop?

That the defining feature of humans -- our large brains -- continued to evolve as recently as 5,800 years ago, and may be doing so today, promises to surprise the average person, if not biologists.

Again why would it stop?

"We, including scientists, have considered ourselves as sort of the pinnacle of evolution,'' noted lead researcher Bruce Lahn, a University of Chicago geneticist whose studies appear in Friday's edition of the journal Science.

Okay, everyone here with a big ego, raise your hand

"There's a sense we as humans have kind of peaked,'' agreed Greg Wray, director of Duke University's Center for Evolutionary Genomics. '

Creationist Bob: The evil scientists have exposed their lies! inorder for their vaunted "theory of evolution" to work, it can't 'peak or stop.

We are an animal like anyother, I don't think these geneticists shouild get too ahead of themselves

Using DNA samples from ethnically diverse populations, they identified a collection of variations in each gene that occurred with unusually high frequency. In fact, the variations were so common they couldn't be accidental mutations but instead were probably due to natural selection, where genetic changes that are favorable to a species quickly gain a foothold and begin to spread, the researchers report.

Natural Selection, what can't it do?

Lahn offers an analogy: Medieval monks would copy manuscripts and each copy would inevitably contain errors -- accidental mutations. Years later, a ruler declares one of those copies the definitive manuscript, and a rush is on to make many copies of that version -- so whatever changes from the original are in this presumed important copy become widely disseminated.

A nice indirect jab at the Bible, how quaint

Other scientists urge great caution in interpreting the research.

With good cause too!
"We, including scientists, have considered ourselves as sort of the pinnacle of evolution,''-Bruce Lahn, a University of Chicago geneticist

That the genetic changes have anything to do with brain size or intelligence "is totally unproven and potentially dangerous territory to get into with such sketchy data,'' stressed Dr. Francis Collins, director of the National Human Genome Research Institute.

Also a good point

Aside from not knowing what the gene variants actually do, no one knows how precise the model Lahn used to date them is, Collins added.

...esspecially if you take his apparent ego into account

Lahn's own calculations acknowledge that the microcephalin variant could have arisen anywhere from 14,000 to 60,000 years ago, and that the uncertainty about the ASPM variant ranged from 500 to 14,000 years ago.

Now those are big margins of error, and this guy is just jumping to conclusions?

[Superboy]

Why would anyone who wasn't completely ignorant be surprised by this? There is no actual end to evolution, no set goal. Just constant adaptation.

Yeah, but does natural selection really affect humans in society in that way?

Do smart people live longer and breed more? Like kaikatsu said, stupid people tend to breed at least as much as smart people.

So my question is, what force is driving the human brain to evolve? What factors are causing natural selection in this case?

[RedImperator]

I would HOPE its still evolving, given how may stupid people there still are in the world.

But haven't you noticed stupid people tend to breed even MORE? I've often wondered if intelligence had some kind of evolutionary selection against it...

Except intelligence isn't strictly determined by genetics, and nor is it a single unitary concept that can be measured with a single number.

And of course, the higher birth rate of stupid people (a claim, by the way, I've never seen verified--POOR people do tend to have more children, but that's not the same thing) should be offset by their higher death rate.

[kaikatsu]

Both good points. I was speaking from opinion, not statistics. That being said, most people I see who have lots of children are the ones making very poor choices in life... and that does not always match up with their economic situation.

Now that I think about it -- would a higher death rate for stupid people matter if the death came sufficently late in life? Anything which doesn't prevent breeding can't be genetically selected against, can it?

[RedImperator]

Both good points. I was speaking from opinion, not statistics. That being said, most people I see who have lots of children are the ones making very poor choices in life... and that does not always match up with their economic situation.

There are cultural reasons for having large families which have nothing to do with intelligence, especially outside the first world. Also, be careful not to confuse ignorance with stupidity--there are entirely too many people who, thanks to woeful sex education, simply have no idea how to prevent pregnancies.

Now that I think about it -- would a higher death rate for stupid people matter if the death came sufficently late in life? Anything which doesn't prevent breeding can't be genetically selected against, can it?

In my experience, the dumbest creature alive is a teenage boy. I don't have the statistics on me, but I'd be shocked if the rates for violent and/or accidential death aren't highest for men between the ages 15 and 25, which is young enough that most will have few or no children. If you want to prevent a genetic trait from spreading, prevent the men who have it from breeding--a woman can have, at the absolute most, twenty or so children in her lifetime, while a man can have thousands.

[anybody_mcc]

Why would anyone who wasn't completely ignorant be surprised by this? There is no actual end to evolution, no set goal. Just constant adaptation.

Yeah, but does natural selection really affect humans in society in that way?

Do smart people live longer and breed more? Like kaikatsu said, stupid people tend to breed at least as much as smart people.

So my question is, what force is driving the human brain to evolve? What factors are causing natural selection in this case?

I think culture ( and i include science , beliefs , technology , ... ) has mostly taken a priority role in our adaptation to "natural" environment, because it is changing more quickly than genepool can , but there are still many ways in which selection can work : sexual preferences , diseases , "unnatural" pressures created by the culture and our "artificial" environment.

On the other hand i really don't think there has been any radical improvement in our mental capabilities in last 10000 years. But that's just personal opinion and we will probably have to wait a long time before we can say if it's true.

[anybody_mcc]

And of course, the higher birth rate of stupid people (a claim, by the way, I've never seen verified--POOR people do tend to have more children, but that's not the same thing) should be offset by their higher death rate.

Problem is that thanks to our greatest adaptational feature , the culture , this is not necessarily true , because the smarter individuals are ensuring survival of the not so smart ones ( by inventing things that help even the stupid ones ). Of course it can reach some balance , but the ratio smart/stupid is more and more in favor of stupid people if they have more children and in the same time our culture ( civilization ) is better and better at ensuring their survival despite their stupidity.

[RedImperator]

And of course, the higher birth rate of stupid people (a claim, by the way, I've never seen verified--POOR people do tend to have more children, but that's not the same thing) should be offset by their higher death rate.

Problem is that thanks to our greatest adaptational feature , the culture , this is not necessarily true , because the smarter individuals are ensuring survival of the not so smart ones ( by inventing things that help even the stupid ones ). Of course it can reach some balance , but the ratio smart/stupid is more and more in favor of stupid people if they have more children and in the same time our culture ( civilization ) is better and better at ensuring their survival despite their stupidity.

Culture is just as capable of killing people as it is keeping them alive. We've invented many thousands of highly efficient ways to die that would have astonished our forebearers. In fact, I'd argue that it's easier to get accidentally killed in a modern technological society than it was in prehistoric times. Cro-magnon village idiots were not confronted daily with electrical outlets, cars, guns, household chemicals, balconies, railroad crossings, gasoline, propane tanks, et cetera.

You're conflating simple idiots with severely disabled people--diabetics, the mentally retarded, the congenitally blind--who would be almost certain to die in prehistoric society but are living to reproductive age now. Besides the lack of any emprical evidence and its oversimplified view of intelligence and the heredity thereof, "The idiots are outbreeding us!" argument falls on its face because it doesn't take into account it's very easy to get killed in modern society, and the primary victims of accidental death should be young men who would otherwise be entering their prime breeding years.

[anybody_mcc]

Culture is just as capable of killing people as it is keeping them alive. We've invented many thousands of highly efficient ways to die that would have astonished our forebearers. In fact, I'd argue that it's easier to get accidentally killed in a modern technological society than it was in prehistoric times. Cro-magnon village idiots were not confronted daily with electrical outlets, cars, guns, household chemicals, balconies, railroad crossings, gasoline, propane tanks, et cetera.

Of course we have more lethal weapons , but they are killing stupid and smart with the same probability.
Something else are non-weapon products. But these products are made as foolproof as possible , and i am yet to see any statistic showing that stupid people have significantly higher probability of dying in the accident. Problems with this see comment below.

You're conflating simple idiots with severely disabled people--diabetics, the mentally retarded, the congenitally blind--who would be almost certain to die in prehistoric society but are living to reproductive age now. Besides the lack of any emprical evidence and its oversimplified view of intelligence and the heredity thereof, "The idiots are outbreeding us!" argument falls on its face because it doesn't take into account it's very easy to get killed in modern society, and the primary victims of accidental death should be young men who would otherwise be entering their prime breeding years.

I am not advocating "The idiots are outbreeding us!" argument. My model was quite oversimplified and i am not sure that stupid people have really higher birth rate , but I just tried to show that stupid/smart ratio may not be constant and in fact may be rising.
Also i am not sure about the claim that young men have such a high accident probability.
But frankly this whole discussion has one big problem you already mentioned : very "fuzzy" definition of smart/intelligence. And until that is clarified , exact discussion is problematic.

[Rogue 9]

Study Suggests Human Brains Still Evolving

And in other news, water is wet and the sky is often blue. Methinks this deserves a spot on the least surprising AP headlines.

[dragon]

I would HOPE its still evolving, given how may stupid people there still are in the world.

But haven't you noticed stupid people tend to breed even MORE? I've often wondered if intelligence had some kind of evolutionary selection against it...

Except intelligence isn't strictly determined by genetics, and nor is it a single unitary concept that can be measured with a single number.

And of course, the higher birth rate of stupid people (a claim, by the way, I've never seen verified--POOR people do tend to have more children, but that's not the same thing) should be offset by their higher death rate.

When my wife went to her 10 year reunion we noticed a very strange thing all of the ones that either dropped out or didn't get their gymnamism (german equivalent of highschool) had on average 2 or more kids. While those that continued their education had fewer kids. Those that had at least masters or higher had almost none.

[Zero]

I've noticed similar things with some of my older friends, and old friends of my parents. The ones who are obviously more stupid typically have like... 4 kids, and the smarter of them won't probably be hitched, or will have a marriage with no kids involved.

Is it possible that stupididy evolves in a specific way that makes those carrying the 'stupid' gene want to have more children. That would explain why most rabid fundies I know who are over the age of 30 have like... 5 kids..

[RedImperator]

But haven't you noticed stupid people tend to breed even MORE? I've often wondered if intelligence had some kind of evolutionary selection against it...

Except intelligence isn't strictly determined by genetics, and nor is it a single unitary concept that can be measured with a single number.

And of course, the higher birth rate of stupid people (a claim, by the way, I've never seen verified--POOR people do tend to have more children, but that's not the same thing) should be offset by their higher death rate.

When my wife went to her 10 year reunion we noticed a very strange thing all of the ones that either dropped out or didn't get their gymnamism (german equivalent of highschool) had on average 2 or more kids. While those that continued their education had fewer kids. Those that had at least masters or higher had almost none.

Of course another way to look at it is that people with a master's or higher don't have time for children. I don't know how the German higher education system is structured, but here in the States, the earliest you could concievably have a masters, barring being some kind of workaholic genius that plows through undergrad in two years, is four years after graduating high school (assuming you took summer courses to shave a year off undergrad and got a one year master's program), and the more typical number is closer to six. Then, presumably, you want to do something with that degree besides hang it on the wall to look pretty while you chase brats around the house, at least for a little while. I'm not surprised at all that people who had advanced degrees wouldn't have many children ten years after high school, since it would be nearly impossible to acquire those degrees and raise children at the same time.

And of course, it bears pointing out that even if there is a direct correlation between education level and number of children (which there likely is), education is not the same thing as intelligence. Some of the biggest dummies I ever met I met in college, while I know more than one person plenty sharp enough to get an advanced degree who through some combination of circumstances or shortsightedness dropped out of high school.

[RedImperator]

Culture is just as capable of killing people as it is keeping them alive. We've invented many thousands of highly efficient ways to die that would have astonished our forebearers. In fact, I'd argue that it's easier to get accidentally killed in a modern technological society than it was in prehistoric times. Cro-magnon village idiots were not confronted daily with electrical outlets, cars, guns, household chemicals, balconies, railroad crossings, gasoline, propane tanks, et cetera.

Of course we have more lethal weapons , but they are killing stupid and smart with the same probability.
Something else are non-weapon products. But these products are made as foolproof as possible , and i am yet to see any statistic showing that stupid people have significantly higher probability of dying in the accident. Problems with this see comment below.

I was referring more to people who ventilate their skulls playing Russian Roulette with a semiautomatic. Obviously, advanced weapons don't discriminate, but most people in the first world will never be on the recieving end of them.

The fact, meanwhile, that dangerous products are made as foolproof as possible in no way changes the fact that people with less common sense are more likely to get killed by them--or are you suggesting smart people are more likely to smoke around a gas can or reach under a running lawnmower to clear a jam? Of course, "common sense" isn't the same as smart, is it, since we probably both know people with plenty of book smarts who routinely do incredibly boneheaded things, which is why ultimately this argument is futile.

You're conflating simple idiots with severely disabled people--diabetics, the mentally retarded, the congenitally blind--who would be almost certain to die in prehistoric society but are living to reproductive age now. Besides the lack of any emprical evidence and its oversimplified view of intelligence and the heredity thereof, "The idiots are outbreeding us!" argument falls on its face because it doesn't take into account it's very easy to get killed in modern society, and the primary victims of accidental death should be young men who would otherwise be entering their prime breeding years.

I am not advocating "The idiots are outbreeding us!" argument. My model was quite oversimplified and i am not sure that stupid people have really higher birth rate , but I just tried to show that stupid/smart ratio may not be constant and in fact may be rising.
Also i am not sure about the claim that young men have such a high accident probability.

Source

Now, that chart doesn't separate causes of death, but if you read the source, you see that accidental death is the leading cause of death for all people under 25, and that the death rate for males is much higher (it's also higher for black males than any other group, thanks to an inordinately high homicide rate for black males).

But frankly this whole discussion has one big problem you already mentioned : very "fuzzy" definition of smart/intelligence. And until that is clarified , exact discussion is problematic.

I don't know, frankly, if it can be defined in any way that would lead to a useful conclusion from this discussion.

[General Zod]

I've noticed similar things with some of my older friends, and old friends of my parents. The ones who are obviously more stupid typically have like... 4 kids, and the smarter of them won't probably be hitched, or will have a marriage with no kids involved.

Is it possible that stupididy evolves in a specific way that makes those carrying the 'stupid' gene want to have more children. That would explain why most rabid fundies I know who are over the age of 30 have like... 5 kids..

A throwback survival instinct, possibly. Many animals in the wild tend to breed as many offspring as they can in hopes that at least a handful will survive, due to how harsh their environments are.

[Zero]

Has anybody ever done a study on a correlation between IQ and the number of kids you have? I don't suspect that there would be any conclusive data, but that may alleviate some fears that humanity will become progressively dumber from this point on.

[Nephtys]

One thing to note of course is that civilization itself is an equalizer, saving those who would certainly be killed in a 'in the wild' kind of scenario, such as the mentally or physically disabled. Now, although accidental deaths do occur, they are just that. Accidental. Accidents happen in nature too..

But now I personally believe that our biological evolution no longer has any specific focus compared to our behavioral evolution. Biological evolution takes such ridiculous lengths of time to get any change done, but instead by having society adapt, we can get most of the benefit in years, not eons.

[General Zod]

Has anybody ever done a study on a correlation between IQ and the number of kids you have? I don't suspect that there would be any conclusive data, but that may alleviate some fears that humanity will become progressively dumber from this point on.

IQ is a poor measurement of intelligence. You can have someone with a ridiculously high
IQ who's still a fundamentalist dipshit and turns their brain off when the topic of magic sky pixies comes up, for example.

[RedImperator]

Has anybody ever done a study on a correlation between IQ and the number of kids you have? I don't suspect that there would be any conclusive data, but that may alleviate some fears that humanity will become progressively dumber from this point on.

IQ is worthless for doing anything but identifiying kids with mild retardation, which is exactly what Binet intended when he developed it. It's useless as a way to compare people who fall in the "normal" range.

[Zero]

That's true, but what better measurement would there be? Even if it's a poor measurement, it could reveal a general trend that hadn't been examined before.

Besides, the fundie dipshit with a high IQ isn't necessarily stupid, he's just wrong. Genetics most certainly play no role in how indoctrinated one becomes. That IS social factors, so I don't see why that would be relevant. I'm just wondering if it's possible that the stupid people DO outbreed us, because most personal experience points towards that.

[RedImperator]

That's true, but what better measurement would there be? Even if it's a poor measurement, it could reveal a general trend that hadn't been examined before.

No, it doesn't, because once you're in the normal range, the IQ numbers correlate so strongly with education, race, and socioeconomic background it's clear they're measuring factors which have nothing to do with innate intelligence. When I say IQ is useless for comparing people with normally functioning brains, I mean exactly that. It's worse than a poor measurement, it's a measurement which is actively misleading. There are too many variables that go into making an IQ score to draw any conclusion about intelligence from them.

Besides, the fundie dipshit with a high IQ isn't necessarily stupid, he's just wrong. Genetics most certainly play no role in how indoctrinated one becomes. That IS social factors, so I don't see why that would be relevant. I'm just wondering if it's possible that the stupid people DO outbreed us, because most personal experience points towards that.

Personal experience also points to time and space being absolute, nations having emotions like people, and species being fixed and unchanging. There are plenty of counter-intuitive concepts in all fields; this is simply one of them. The fact is, intelligence itself is culturally defined. We pretend it's one thing by picking the skill sets we consider measures of intelligence and ignoring the rest, and we compound the error in discussions like this with unjustified assumptions about the nature of intelligence and birth rates of "stupid" versus "smart" people.

In my opinion, if the stupid to smart (whatever those words actually mean) ratio is changing, it's changing because of cultural factors like access to education, nutrition, and the like, not genetics. There's no evidence whatsoever that stupid and smart are heritable in the normal range, nor is there evidence that stupid is outbreeding smart, nor, for that matter, is there any useful definition of stupid or smart.