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    Intelligence And Mental Illness May Be Ancient Genetic Accident
    By News Staff | December 2nd 2012 06:30 PM | 10 comments | Print | E-mail | Track Comments

    Neuroscientists think they have some insight for evolutionary biologists into how humans, and other mammals, have evolved to have intelligence. They say they have identified the moment in history when the genes that enabled us to think and reason evolved.

    This point 500 million years ago provided our ability to learn complex skills, analyze situations and have flexibility in the way in which we think, says Professor Seth Grant of the University of Edinburgh, who led the research -  "One of the greatest scientific problems is to explain how intelligence and complex behaviours arose during evolution." 

    They say their research also shows a direct link between the evolution of behavior and the origins of brain diseases and that the same genes that improved our mental capacity are also responsible for a number of brain disorders.

    Intelligence in humans developed as the result of an increase in the number of brain genes in our evolutionary ancestors, that is obvious, but the researchers suggest that a simple invertebrate animal living in the sea 500 million years ago experienced a 'genetic accident', which resulted in extra copies of these genes being made. This animal's descendants benefited from these extra genes, leading to behaviorally sophisticated vertebrates – including humans. 

    The research team studied the mental abilities of mice and humans, using comparative tasks that involved identifying objects on touch-screen computers. They then combined results of these behavioral tests with information from the genetic codes of various species to work out when different behaviors evolved.

    They found that higher mental functions in humans and mice were controlled by the same genes. When these genes were mutated or damaged, they impaired higher mental functions. 

    "Our work shows that the price of higher intelligence and more complex behaviours is more mental illness," said Grant.


    Published in two papers in Nature Neuroscience.

    Comments

    damonisherwood
    It begs the question of why only humans have developed intelligence to the point where we can understand cause and effect to the extent that we can manage them. If intelligence is the super tool we think of it as (and it is hard to see how it couldn't be highly beneficial to a species) why only humans in the history of life on earth? Evolution has found its way to all sorts of unlikely solutions - why is intelligence so incredibly difficult?
    damonish
    Gerhard Adam
    I think the value of intelligence is often overrated because it's so human specific that we can't imagine being without it.  Yet, it would be hard to argue that any particular creature being examined doesn't have precisely the tools [and intelligence] it needs to survive in it's particular niche.

    In fact, a strong argument can be made that human existence hasn't actually been long enough to conclude that evolution's "experiment with higher intelligence" is successful.  In my view, what's much more significant is how readily we confuse human innate intelligence with human society's intelligence which is responsible for our modern technology.  After all, individuals aren't likely more or less intelligent than they've been for thousands of years, so our modern society is a product of our social organization [where each individual is only responsible for a tiny bit] rather than something we could broadly term human intelligence.

    In fact, people often point out how humans have created artistic masterpieces and yet, in reality, it is a miniscule percentage of humans that have ever produced such works.  By and large, humans are simply intelligent enough to operate within their society [with a few notable exceptions] and the ability to not have to repeat history by having external records that avoid having to relearn past lessons or reacquire past knowledge.

    That's not to say that these aren't significant events, but we often make more of it, than recognizing that it's only a few select differences that have accounted for the larger apparent disparity.
    Mundus vult decipi
    Whilst it's true that most people use just enough of their intelligence to suvive and do not produce masterpieces, the point about human intelligence is that it is a substrate for abstract reasoning. We can think about thinking sufficiently clearly to be confident that basic logic (and a determination to apply it) can, in principle, allow us to solve any problem that has a solution. Merely being aware of cause and effect is not sufficient, it it the ability to generalise and apply the principle that has allowed memes to take over from genes as the dominant mode of evolution in homo sapiens for a few thousand years.
     
    Fortunately some of our more primitive modes of thought perceive this as competition rather than a system phenomenon :) I say "fortunately" because although the strength of the memetic "side" is still limited, we are rapidly reaching the point where our memes are going to declare all-out war on our genetic heritage and emancipate themselves from it. My sense of "I" definitely aligns with my thought-life here, not my DNA, so I know which side I am on and welcome the coming slaughter. 

    There is some urgency to understanding the fundamentals of morality, spirituality etc before this point occurs otherwise other aggressive memes - be they religious fundamentalism, political correctness or sheer old-fashioned self-righteous defence of the status quo - will take over and steer the bloodbath into something having the appearence of personal freedom but actually as repressive as our present enslavement to disease, stifling religion, the banking system and death. It's a dangerous time and not helped by the possibility of speeding it all up with even faster substrates built of electronics or quantum systems...

    Meanwhile the single factor which makes this possible is the trait which distinguishes human intelligence from that of other animals - the ability to abstract ones thinking from concrete situations and to reflect upon that abstraction. Alan Turing, for instance, proved that a very simple computing engine could find the proof of any mathematical theorem - a complementary idea to the famous incompleteness theorems of Kurt Godel! So it seems likely that a rather simple reasoning substate can understand absolutely anything as long as it can be expressed in unambiguous language. (and as a corrollary create masterpieces!) Human reason is already emancipated from its organic origins. Monkeys thinking ahead about how to fetch a banana or how not to annoy the leader of the troupe are not quite in the same league! As with our soon-to-be-displaced genetic code, there is a lot of awkwardness and inefficient kludges in our mental equipment - but it's gone past the point of no return now.

    Gerhard Adam
    Monkeys thinking ahead about how to fetch a banana or how not to annoy the leader of the troupe are not quite in the same league!
    Well, as you know, I disagree with your assessment.  Humans are precisely in this league when one examines the overwhelming majority of individuals that actually inhabit this planet.  Even the previous statement regarding Turing and Godel would receive blank stares from the majority of humans on this planet, so I don't believe we're even remotely close to escaping our organic origins.

    I have no doubt that human capabilities could reach tremendous levels, but I don't believe it will ever happen, because of unwarranted hubris and impatience.  We think that with a little understanding we can rearrange the manner of the world's operation. 
    My sense of "I" definitely aligns with my thought-life here, not my DNA, so I know which side I am on and welcome the coming slaughter.
    Again, I disagree because my sense is that our "thought-life" is littered, not with abstractions, but with self-indulgent fantasies.  So, in my view, a memetic revolution will simply cause humanity to implode.
    Mundus vult decipi
    You need to brush up on your history! The first memetic revolution has already occurred, it is many thousands of years old. What remains is for the in-fighting of different memetic factions to be resolved! One of these is our evolutionary legacy of reactionary memes.  However the scenario of a complete memetic takeover by desirable memes was an illustration of the potential of human intelligence, not a prediction that the outcome would be utopia. I am certainly not an optimistic trans-humanist.  I suspect we are in quite close agreement really.

    Just to be clear, my point is that because it has acheived emancipation from its origins in immediate goal-oriented behaviour, human intelligence differs significantly from that of other animals. It is already a substrate for unlimited thought. Whether we use it for desirable ends (not forgetting Sascha's global suicide scenario where we eliminate irrational goals like happiness and have nothing left to do but shut down) is another matter!
     








    Bonny Bonobo alias Brat
    It begs the question of why only humans have developed intelligence to the point where we can understand cause and effect to the extent that we can manage them. If intelligence is the super tool we think of it as (and it is hard to see how it couldn't be highly beneficial to a species) why only humans in the history of life on earth?
    I'm afraid it begs the question to me, of why you would think what you are saying is even true? Watch this Youtube video demonstrating a scientific experiment exploring Capuchin monkeys' intelligence and sense of fairness and tell me whether you still believe what you are saying here please? BTW the same psychological experiment has been reproduced with similar results in many other animals and species.
    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    damonisherwood
    Granted that other animals - particularly primates - have developed rudimentary levels of intelligence. But it can not be argued that any other animal has ever evidenced the ability to understand cause and effect - and therefore consciously manage it - to the extent that humans have.  We humans are unique, if not in the quality of our intelligence, then in its quantum. And I am still not convinced that anyone has really nailed the reason that no other species has progressed down the intelligence trail to the extent that humans have. Reasons such as energy usage and longer pregnancy appear to be small impediments compared with the astronomical advantage of intelligence. Every species that has ever lived should have been banging on the door! 
    damonish
    Gerhard Adam
    I'm sorry, but your reasoning is simply human bias.  Intelligence is the only weapon that humans have, so consequently it has served double duty.  First in helping us survive, and then in the development of a social organization that has created modern technology.  If we look away from our modern society to present-day hunter gatherers, we can see human intelligence at work, but it resembles nothing of which you speak.

    Other animals don't need such intelligence, since they generally possess natural weapons for predators, unlike humans.  So, certainly humans are unique, in being one of the only predators that has no natural weapons.  Therefore the brain was what needed to be used.

    It's all a matter of perspective, because humans value intelligence, we wonder why no other creature possesses it to our degree.  However, one could just as readily imagine a grizzly bear, or a lion [if they had such thoughts] wonder about how pitifully weak humans are and why they didn't follow the evolutionary path of size and weaponry.

    Let's also remember that human survival, today, is not based on intelligence as much as a dependency on infrastructure [of which no individual understands nor is capable of operating it alone].  What makes this important is that if we removed that infrastructure, you'd quickly discover that the overwhelming majority of humans aren't nearly as intelligent as you might think.  We appear to have the advantage at present, as long as we can maintain ourselves in our cocoon.  If anything penetrates that, we are largely hapless victims [witness the results of almost any natural disaster].

    Moreover, if we consider some other possible explanations in our evolutionary past, it's entirely possible that there were several other primate species that possessed similar intelligence, yet all indications are that modern humans wiped them out.  So, it's quite possible that other intelligences could never evolve, because competition wouldn't tolerate coexistence.

    On a final note, let's remember that humans experienced a population bottleneck that they survived by little more than luck.  Had there been just a bit of bad luck, "intelligence" might never have culminated in a human dominated world.  As a result, whatever else one may think, it is clear that "intelligence" is merely one adaptation out of many, and it is by no means assured that it is an advantage.  We perceive it that way now, but until we've actually got a bit of longevity to our existence, we're relative newcomers and just as likely to fail as we are to persist.  Dinosaurs survived for several hundred million years.  Do you think human intelligence can beat that?
    Mundus vult decipi
    Gerhard Adam
    On a separate note, the assertions in this article are ridiculous.  Of course, it's a genetic accident, since suggesting anything else assigns a direction and purpose to natural selection.
    ...the researchers suggest that a simple invertebrate animal living in the sea 500 million years ago experienced a 'genetic accident', which resulted in extra copies of these genes being made. This animal's descendants benefited from these extra genes, leading to behaviorally sophisticated vertebrates – including humans.
    Wow ... in this one statement they've managed to restate the obvious and rediscover Darwin.
    They found that higher mental functions in humans and mice were controlled by the same genes. When these genes were mutated or damaged, they impaired higher mental functions.
    How is this anything but a DUH?  I'll climb out on a limb here and be willing to bet, that with a bit of extra research, it will be discovered that any function that is controlled by genes will be impaired if those genes are damaged.
    Mundus vult decipi
    Steve Davis
     "...the assertions in this article are ridiculous."
    Astoundingly so, Gerhard.
    Even bacteria demonstrate intelligence.
    They communicate, after all.