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9/22/2017 12:11:25 AM
Posted: 9/9/2005 6:43:16 AM EDT
[Last Edit: 9/9/2005 6:48:17 AM EDT by AssaultRifler]

I'll start this out in GD, probably will get moved later on to the Pit
who says we can't monitor evolution?

linky

Human brains enjoy ongoing evolution

* 15:06 09 September 2005
* NewScientist.com news service


The human brain may still be evolving, new research suggests. New variants of two genes that control brain development have swept through much of the human population during the last several thousand years, biologists have found.

The evolution of a large, complex brain has been the defining feature of the human lineage – although human brain size has not changed over the past 200,000 years. But it is not apparent whether the new genetic adaptations discovered in human brains have any effect on brain size, or intelligence.

What is more, not everyone possesses the new gene variants, potentially inflaming an already controversial debate about whether brains of different groups of people function differently.

"Whatever advantage these genes give, some groups have it and some don't. This has to be the worst nightmare for people who believe strongly there are no differences in brain function between groups," says anthropologist John Hawks of the University of Wisconsin in Madison, US.
Brain size

There are two new genetic studies that suggest the brain may still be evolving. Geneticist Bruce Lahn of the University of Chicago in Illinois, US, and colleagues analysed the sequences of two genes active in the brain – Microcephalin and ASPM. Both regulate brain size - people carrying a non-functioning mutant copy of these genes suffer microcephaly, where they have a normally structured brain that is much smaller than usual.

First, the researchers sequenced the Microcephalin gene found in 89 ethically diverse people. The team found dozens of variants (or alleles) of the gene, but one particular set stood out. These alleles all carry a specific mutation that changes the protein the gene codes for.

This distinctive mutation is now in the brains of about 70% of humans, and half of this group carry completely identical versions of the gene. The data suggests the mutation arose recently and spread quickly through the human species due to a selection pressure, rather than accumulating random changes through neutral genetic drift.

Analysing variation in the gene suggests the new Microcephalin variant arose between 60,000 and 14,000 years ago, with 37,000 years ago being the team's best estimate. The new mutation is also much more common among people from Europe, the Middle East, and the Americas than those from sub-Saharan Africa.
“Compelling evidence”

The team also sequenced the ASPM gene from the same original sample and again, among dozens of variants, found a defining mutation that alters the protein the gene codes for. Estimates are that the new variant of ASPM first appeared in humans somewhere between 14,000 and 500 years ago, with the best guess that it first arose 5800 years ago. It is already present in about a quarter of people alive today, and is more common in Europe and the Middle East than the rest of the world.

"The evidence for selection is compelling," says population geneticist Rasmus Nielsen of the University of Copenhagen in Denmark. Yet it remains unclear yet how these genes work in healthy people. Many researchers doubt there is any mechanism by which nature could be selecting for greater intelligence today, because they believe culture has effectively blocked the action that natural selection might have on our brains.

Lahn and his colleagues are now testing whether the new gene variants provide any cognitive advantage. Natural selection could have favoured bigger brains, faster thinking, different personalities, or lower susceptibility to neurological diseases, Lahn says. Or the effects might be counter-intuitive. "It could be advantageous to be dumber," Lahn says. "I highly doubt it, but it's possible."

Journal reference: Science (vol 309, p 1717 and p 1720)
Link Posted: 9/9/2005 6:44:09 AM EDT
What the hell is a bain?
Link Posted: 9/9/2005 6:44:32 AM EDT

Originally Posted By highwayman:
What the hell is a bain?



a typo
Link Posted: 9/9/2005 6:51:12 AM EDT
Just had to do that, it was too easy. "...not apparent whether the new genetic adaptations discovered in human brains have any effect on brain size, or intelligence..." This says it all to me. They found something, but don't know what it is or what it does. MJD
Link Posted: 9/9/2005 6:57:28 AM EDT
I heard this on the news last night. I am not really surprised, we do evolve as a species.....

myit
Link Posted: 9/9/2005 7:01:21 AM EDT

Originally Posted By AssaultRifler:
Yet it remains unclear yet how these genes work in healthy people. Many researchers doubt there is any mechanism by which nature could be selecting for greater intelligence today, because they believe culture has effectively blocked the action that natural selection might have on our brains.



The article itself provide the argument for why this is nonsense.


Exactly how - in todays's world - does higher intelligence allow you to breed more than those with lower intelligence? In the ancestral environment, as hunter-gatherers, and before that - sure, higher intelligence would allow you to survive to breeding age BETTER than less intelligent humans, or would allow you to be more successful (once specialized societies invovled) - and give you better access to breeding females. But in today's world? Bah.

It doesn't. In fact, since intelligent people generally often seem to be more responsible than unintelligent people, they are probably LESS likely to have children. From a selction/evolution perspective (at a genetic level) we are likely going to become less intelligent.



I see lots of wlefare families with tons of kids, and lots of my colleagues with none , or one kid. Having kids now is largely a CHOICE, nothing more - not a result of survival or access to reproduction.
Link Posted: 9/9/2005 7:07:13 AM EDT
Exactly. Stupid people dont die, instead they are saved and allowed to breed.

Whats going on in New Orleans is a perfect example.
Link Posted: 9/9/2005 7:21:56 AM EDT

Originally Posted By DK-Prof:

Originally Posted By AssaultRifler:
Yet it remains unclear yet how these genes work in healthy people. Many researchers doubt there is any mechanism by which nature could be selecting for greater intelligence today, because they believe culture has effectively blocked the action that natural selection might have on our brains.



The article itself provide the argument for why this is nonsense.


Exactly how - in todays's world - does higher intelligence allow you to breed more than those with lower intelligence? In the ancestral environment, as hunter-gatherers, and before that - sure, higher intelligence would allow you to survive to breeding age BETTER than less intelligent humans, or would allow you to be more successful (once specialized societies invovled) - and give you better access to breeding females. But in today's world? Bah.

It doesn't. In fact, since intelligent people generally often seem to be more responsible than unintelligent people, they are probably LESS likely to have children. From a selction/evolution perspective (at a genetic level) we are likely going to become less intelligent.



I see lots of wlefare families with tons of kids, and lots of my colleagues with none , or one kid. Having kids now is largely a CHOICE, nothing more - not a result of survival or access to reproduction.



That is why a world altering event is needed to allow the less competitive population to survive, and the more ill equipped segment to die out.

Dinosaurs -> Mammals...
Link Posted: 9/9/2005 7:29:42 AM EDT

Originally Posted By DK-Prof:

Originally Posted By AssaultRifler:
Yet it remains unclear yet how these genes work in healthy people. Many researchers doubt there is any mechanism by which nature could be selecting for greater intelligence today, because they believe culture has effectively blocked the action that natural selection might have on our brains.



The article itself provide the argument for why this is nonsense.


Exactly how - in todays's world - does higher intelligence allow you to breed more than those with lower intelligence? In the ancestral environment, as hunter-gatherers, and before that - sure, higher intelligence would allow you to survive to breeding age BETTER than less intelligent humans, or would allow you to be more successful (once specialized societies invovled) - and give you better access to breeding females. But in today's world? Bah.

It doesn't. In fact, since intelligent people generally often seem to be more responsible than unintelligent people, they are probably LESS likely to have children. From a selction/evolution perspective (at a genetic level) we are likely going to become less intelligent.



I see lots of wlefare families with tons of kids, and lots of my colleagues with none , or one kid. Having kids now is largely a CHOICE, nothing more - not a result of survival or access to reproduction.



Smart people get typcially well paying jobs. More money gets your more women. Who do you think could pull in more money, you or Bill Gates?
Link Posted: 9/9/2005 7:35:13 AM EDT
[Last Edit: 9/9/2005 7:35:37 AM EDT by PAEBR332]

Originally Posted By rasanders22:

Originally Posted By DK-Prof:

Originally Posted By AssaultRifler:
Yet it remains unclear yet how these genes work in healthy people. Many researchers doubt there is any mechanism by which nature could be selecting for greater intelligence today, because they believe culture has effectively blocked the action that natural selection might have on our brains.



The article itself provide the argument for why this is nonsense.


Exactly how - in todays's world - does higher intelligence allow you to breed more than those with lower intelligence? In the ancestral environment, as hunter-gatherers, and before that - sure, higher intelligence would allow you to survive to breeding age BETTER than less intelligent humans, or would allow you to be more successful (once specialized societies invovled) - and give you better access to breeding females. But in today's world? Bah.

It doesn't. In fact, since intelligent people generally often seem to be more responsible than unintelligent people, they are probably LESS likely to have children. From a selction/evolution perspective (at a genetic level) we are likely going to become less intelligent.



I see lots of wlefare families with tons of kids, and lots of my colleagues with none , or one kid. Having kids now is largely a CHOICE, nothing more - not a result of survival or access to reproduction.



Smart people get typcially well paying jobs. More money gets your more women. Who do you think could pull in more money, you or Bill Gates?



And yet the Dutchman and Bill Gates have exactly the same number of wives: 1 each. Hmmmm.

Anyone who thinks the human brain is evolving has never spent much time in GD here.
Link Posted: 9/9/2005 7:40:06 AM EDT
[Last Edit: 9/9/2005 7:41:01 AM EDT by DK-Prof]

Originally Posted By rasanders22:

Originally Posted By DK-Prof:

Originally Posted By AssaultRifler:
Yet it remains unclear yet how these genes work in healthy people. Many researchers doubt there is any mechanism by which nature could be selecting for greater intelligence today, because they believe culture has effectively blocked the action that natural selection might have on our brains.



The article itself provide the argument for why this is nonsense.


Exactly how - in todays's world - does higher intelligence allow you to breed more than those with lower intelligence? In the ancestral environment, as hunter-gatherers, and before that - sure, higher intelligence would allow you to survive to breeding age BETTER than less intelligent humans, or would allow you to be more successful (once specialized societies invovled) - and give you better access to breeding females. But in today's world? Bah.

It doesn't. In fact, since intelligent people generally often seem to be more responsible than unintelligent people, they are probably LESS likely to have children. From a selction/evolution perspective (at a genetic level) we are likely going to become less intelligent.



I see lots of wlefare families with tons of kids, and lots of my colleagues with none , or one kid. Having kids now is largely a CHOICE, nothing more - not a result of survival or access to reproduction.



Smart people get typcially well paying jobs. More money gets your more women. Who do you think could pull in more money, you or Bill Gates?



I honestly don't understand your point?

How is more money getting people MORE WOMEN in today's society? - it's only relevant to "evoltuion: and selctive breeding if it results in MORE CHILDREN (than the competing genetic design, i.e. stupidity)

More money is getting BETTER women - in that women compete for men who can provide for their children (even if they don't have children - it's a genetic imperative). Men with better access to resources will be able to attract more attractivce, more intelligent, etc. women. They will have a better CHOICE.

However - unless that improved access results in MORE CHILDREN than poorer people, it is completely meaningless from an evolutionary perspective.

There are 17 year-old gangbangers with KIDS. THere are worthless drug addicts in prison with KIDS. There are high schoolers with KIDS.

While success and wealth (as a result of intelligence) might give some people access to better quality of women, there is access to REPRODUCTIVE WOMEN at all socioeconomic levels - and usually the people at the lower socioeconomic levels have more kids, and at earlier ages - which are both pehonomonen that provide a "evolutionary" edge.
Link Posted: 9/9/2005 7:42:21 AM EDT
Oh Boy this might get ugly quick . I would be disapointed if we are the best we can do (YOU can DOIT !) . Evolution is such a sloowwww process we just dont have perspective on it . I made a long strip of computer paper into a time line covering 4.5 Billoin years . I dont remember the exact sizes (lenghts)but roughly 40 feet long ....I had to make it that long to even show humans the last 2K years coverd about 1/16 of an inch . It was pretty sobbering . who we tink we is anyway?
Link Posted: 9/9/2005 7:47:18 AM EDT
people are so stupid
Link Posted: 9/9/2005 8:02:22 AM EDT

Originally Posted By DK-Prof:

Originally Posted By AssaultRifler:
Yet it remains unclear yet how these genes work in healthy people. Many researchers doubt there is any mechanism by which nature could be selecting for greater intelligence today, because they believe culture has effectively blocked the action that natural selection might have on our brains.



The article itself provide the argument for why this is nonsense.


Exactly how - in todays's world - does higher intelligence allow you to breed more than those with lower intelligence? In the ancestral environment, as hunter-gatherers, and before that - sure, higher intelligence would allow you to survive to breeding age BETTER than less intelligent humans, or would allow you to be more successful (once specialized societies invovled) - and give you better access to breeding females. But in today's world? Bah.

It doesn't. In fact, since intelligent people generally often seem to be more responsible than unintelligent people, they are probably LESS likely to have children. From a selction/evolution perspective (at a genetic level) we are likely going to become less intelligent.



I see lots of wlefare families with tons of kids, and lots of my colleagues with none , or one kid. Having kids now is largely a CHOICE, nothing more - not a result of survival or access to reproduction.



Doesn't the article suggest "the new Microcephalin variant arose between 60,000 and 14,000 years ago, with 37,000 years ago being the team's best estimate?"

I see your point of course, but we've been civilized--arguably modernized--for the last 5,000 years, which is a very liberal estimation for your theory's exploitation. What selection proccesses were going on "in the wild" during the other 32,000 years? Maybe the population percentage with the "modern" brain was 99% 100 years ago, but has dropped to 70% recently.
Link Posted: 9/9/2005 8:55:43 AM EDT
Ya...the Krells' brains evolved too over several millenia...and look what happened to them!
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