Origin of intelligence linked to ancient genetic accident


Scientists have discovered for the first time how humans – and other mammals – have evolved to have intelligence.

Researchers 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, analyse situations and have flexibility in the way in which we think.

Professor Seth Grant, of the University of Edinburgh, who led the research, said: “One of the greatest scientific problems is to explain how intelligence and complex behaviours arose during evolution.”

The research, which is detailed in two papers in Nature Neuroscience, also shows a direct link between the evolution of behaviour and the origins of brain diseases.

Scientists believe that the same genes that improved our mental capacity are also responsible for a number of brain disorders.

“This ground breaking work has implications for how we understand the emergence of psychiatric disorders and will offer new avenues for the development of new treatments,” said John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust, one of the study funders.

The study shows that intelligence in humans developed as the result of an increase in the number of brain genes in our evolutionary ancestors.

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.

Written By: University of Edinburgh
continue to source article at sciencecodex.com


  1. As a layman I would guess that the most unfortunate ‘genetic accident’ was our psychological predispositions to irrationality.  

  2. “The study also showed that 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 Professor Grant.
    The researchers had previously shown that more than 100 childhood and adult brain diseases are caused by gene mutations.” 

    Any truth in the old saw  ‘A fine line between genius and insanity’?

  3. Complex systems are more vulnerable to damage! (Perhaps that’s why those without complex thinking functions revert to simpleton mode!)

  4. What works is that science reduces magic and other claims to basic explanations. I am refreshed by  what ‘is’,  given enough time to produce anything without human expectations.  So many people seem to be threatened by clean laws of nature explaining how all this world can be as it is. We are so narcissistic we don’t know how narcissistic we are. We are incredibily, and fantastically, insignificant. This type of research helps me live fully.

  5. a lot of discoveries about evolution have referred to a point some 500 million years back. in any ways we’re still all fallout from the cambrian explosion.

    recently i’ve been thinking a lot about eyes (something also to have started evolving around that time), and how important they are, not just for hunting or escaping but for a huge range of complex behaviours. one thing for example, is empathy (something considered unique among one of your ape sub-species). most animals react to a pair of eyes, some animals pretend to have eyes (e.g. butterfly wings) to effect a reaction in other animals such as would-be preditors.

    it’s easy to say that a tendency to react to the pattern made by 2 eyes facing directly could have been selected for by pure chance and that it does nothing but create a fight/dlight reaction in the limbic system but dogs will stare at apes for ages until the ape looks back and they wag their stupid tails in response. i for one am more than happy to let an ape know its breakfast time with a gentle claw on the eyelid. cats use eye contact as a method of communication, we know when another cat (or ape) looks at us and gently closes their eyes they must be secure enough to not need to look around and we relax a bit.

    my point being that with animal eye contact there seems to be an understanding that eyes on other beings are there for them to look with. which to me is the start of empathy, of imaging a situation from another beings point of view

    i know it’s a bit off topic but the referal to that 1/2 billion year era has got me wondering just how much stuff went on that has yet to be discovered to be crucial in creating everything about us, including the supposed recent changes in life

  6. I should read the paper on how genes make accidents before I read this one. I didn’t know they were following a guide. How else do you make an accident but to veer from the predetermined path. Sounds dumb

  7. I wence when I see articles such as this. Without DNA or tissue evidence from 500 million years ago, how can scientists conclude this as fact. It seems to me that the scientific question was framed against common sense reasoning , and the science was then made to fit this outcome. The rise of intelligence went hand in hand with the rise of brain disorders , not too hard to believe , gene replication and mutation , an established fact. I for one do not accept 500 million years ago, at least if it is based on molecular genetics.

  8. I haven’t read the actual journal article, but if it arose from gene duplication, then it would have come about through chromosomes misaligning during the meiosis process, which occurs when gametes are formed. That could be considered an accident.

  9. The Psychiatric Profession .. a latter-day pseudo-scientific cult …?

    “This ground breaking work has implications for how we understand the emergence of psychiatric disorders and will offer new avenues for the development of new treatments,”

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