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The genetics of consciousness

Nipple of a cat. Nose of a pig. Hair of a poodle. Eyes of a baboon. Brain of a chimpanzee. If this sounds like a list of ingredients for a witches’ cauldron, think again, for it’s merely a reminder of how many general characteristics we share with other mammals. This similarity in basic body parts has a genetic basis. So humans and chimps share 99 percent DNA similarity in our protein–coding genes and even the tiny mouse is 85 percent similar to us in this respect. Yet what is most remarkable about human beings is not what we have in common with other animals, but what distinguishes us as a species.

One key human difference is our capacity to shape the world using tools. Although some other species also use tools, what distinguishes humans is the way we have made tool use a systematic part of our lives, as well as the fact that our tools evolve with each new generation. So while there is little sign that the life of a chimpanzee in the jungle is that different from when our two species diverged seven to eight million years ago, in the last 50,000 years humans have gone from living in caves to sending spaceships to Mars.

Another unique attribute of our species is our capacity for language. This capacity is central to our ability to communicate with other humans, but is far more than just a communication system, being also a conceptual framework of symbols that makes our relationship to the world completely different to any other species. It is this that allows us to describe the properties and location of things, what happened to them in the past and might happen in the future.

Such unique features must ultimately be based on differences in the biology of the human brain, and the genetic information that underpins this. Our brains are the most complex structures in the known universe, containing around 100 billion nerve cells joined by some 100 trillion nerve connections. Understanding how human self-conscious awareness arose within this organ, why it is lacking in the brains of our closest biological cousins, and relating this to genetic differences between humans and chimps, is the biggest challenge in biology today.

DNA brain, © comotion_design, via iStock Photo.
DNA brain, © comotion_design, via iStock Photo.

Importantly, recent studies have identified major differences in the times at which particular genes are expressed during development of human brains compared to those of chimps. Such differences are especially prominent in the prefrontal cortex, a brain region involved in complex thought, expression of personality, decision making and social interaction. In particular, genes involved in formation of new synapses – the connections between nerve cells – peak in expression several months after birth in chimp prefrontal cortex but only after five years of age in this region in humans. This fits with the fact that human children have a much more extended period of learning than apes, and indicate that our brains are being restructured in response to such learning for a far longer period.

The many differences identified in the patterns of gene expression in the human brain compared to that of the chimp complicates the process of trying to identify the key ones that underlie our unique attributes of consciousness and self-awareness. As such, there is increasing interest in identifying whether these large scale differences reflect alterations in a much smaller number of ‘master–controller’ genes that code for proteins that regulate other genes. One such protein is of interest both because it is a master regulator of synapse formation, and because its action was subtly different in Neanderthals, suggesting that delayed synapse formation was one factor distinguishing Homo sapiens from these proto-humans.

Until recently gene expression was thought to be only regulated by proteins. However, recent studies show that certain forms of RNA, DNA’s chemical cousin, also play a key role in this process. One such regulatory RNA, abundant in the prefrontal cortex of humans, but not of chimps, has been shown to be an important regulator of nerve stem cell proliferation. This is interesting since neurogenesis – the growth of new neurons from such stem cells – is important not just during embryonic brain development, but is increasingly being recognised as an important process in the adult human brain.

Such a reassessment of the importance of RNA as a regulatory molecule is only one way our concept of the genome is changing. So we are also recognising that far from being a fixed DNA ‘blueprint’, the genome is a complex entity exquisitely sensitive to signals from the environment. These so–called ‘epigenetic’ signals can affect genome function in a finely graded fashion like a dimmer switch, and even have a built–in timing mechanism due to the fact that different genome modifications can be reversed at different rates. All this makes this type of gene regulation ideally suited for involvement in the complex processes of learning and memory. And indeed recent studies have shown that interfering with epigenetic changes in brain cells has profound effects on memory and learning processes in animal models.

Perhaps most surprisingly the genome’s very stability is being called into question, with evidence that genomic elements called transposons, can move about, sometimes to the detriment of normal cellular function, but also acting as a new source of genome function. Intriguingly, the hippocampus, a brain region associated both with memory formation and forming new nerve cells through neurogenesis, is particularly prone to transposon activity.

Some scientists believe increased transposon activity could either change human behaviour allowing the individual to become more adaptable to a new environment, or alternatively increase the risk of mental disorders, depending on the particular environmental pressure. This would challenge the long–held idea that at the genomic level, all cells in an individual’s brain are essentially equivalent. Instead, an individual’s life experience may profoundly the genomes of different brain cells, and even identical twins may differ considerably in their brain function, depending on their particular experiences in life.

In studying how epigenetic information might be transmitted to the genome, the main focus has been upon adverse effects such as stress. So, a recent study showed that telomeres, the protective structures at the ends of our chromosomes, can shorten much more rapidly in some children exposed to extremely stressful situations. But there are also tantalising hints that more positive life events might have a beneficial effect upon the brain through an epigenetic route.

Most controversial is the question of whether epigenetic effects upon the genome can be passed down to future generations. In particular, the finding that effects of stress in mice can be passed on to offspring by a route involving regulatory RNAs that may originate in the brain, and travel in the blood to the sperm, suggests that the connection between the sex cells and the rest of the body, particularly the brain, may be more fluid than previously thought.

Such findings have led epigenetic researcher Brian Dias of Emory University, Atlanta, to recently say that ‘if science has taught me any­thing, it is to not discount the myriad ways of becoming and being’. All of which means that for those interested in the complex nexus of biological and social influence, even more exciting findings undoubtedly lie ahead.

Recent Comments

  1. Peter Kinnon

    Jon Parrington remarks
    ” Understanding how human self-conscious awareness arose within this organ, why it is lacking in the brains of our closest biological cousins, and relating this to genetic differences between humans and chimps, is the biggest challenge in biology today.”

    This is actually no great challenge at all!

    On the contrary, it is rather simply explicable.

    It is essentially attributable to that stage in our ancestry where the snout was replaced by the hands for the acquisition and pre-processing of foods. A step that produced near-obligate tool use.

    The pathway culminating in the extraordinary innervation of the hands and the co-evolution of reflexive consciousness with the ability to import, export and to store imagination externally (a feature that we call “language”) is described in my latest book “The Intricacy Generator: Pushing Chemistry and Geometry Uphill”. Now available as 336 page illustrated paperback from Amazon, etc.

  2. Michael Tripper

    I am tired of this stuff, my work shows where Consciousness arises in Nature. PERIOD.

    Synopsis

    Time is a natural part of the environment and the sense of time is a perceptual sense identical or similar to vision, hearing, sound, touch and taste.

    Consciousness is the logical outcome of perceiving time within the environment. Just as advanced organisms can manipulate parts of their environment using arms, claws, feelers, appendages, etc, the brain has evolved to the point where it can perceive and manipulate time which is the source for what humans call the mind and/or consciousness.

    This work will show the close relationship between the basic structure of time, its relationship to the kinase CaMKII and how that relates to memory, thought and other aspects of consciousness.

    What is Conscious
    It’s a pretty hard question because one uses one’s consciousness when one asks the question thus the conundrum becomes, can I even understand consciousness if I am using it right now – how can I reasonably observe something which is being used to observe itself? How can the observer observe itself without compromising what is observed? This will be answered.

    From a purely thought perspective, when one goes in search of this information, what is consciousness, one has to be almost brutal in one’s analytical ability – there can be no compromises, no white lies to ease the pain of the offended or potentially offended, especially oneself. Brutal honesty has to be a key ingredient in any analysis, but it is even more crucial to the undertaking at hand.

    Another crucial component is of course knowledge. Beyond simply what we know, we have to examine how do we know it? This question is very important because not only does data exist but we must also understand how that data was collected over the centuries. Then the question of what is knowledge also becomes relevant.

    So what is consciousness? I have been looking at what is existence and reality since I was a teenager. It has been the most important thing in my life ever since. Through this search for knowledge it became apparent that our own minds, my mind, consciousness and the brain have a lot to do with what we perceive to be reality. Even at the start of this quest, I came upon a hole in our knowledge.

    Many years ago when I was 16 or so I realized that there was a concept out there that we just gloss over as a given. At the time, I did realize it was important, but I wasn’t thinking about it in terms of consciousness, nor was my knowledge level sufficient to finally pull it all together.

    Today, over 25 years later, I will start to present what I know now about that blind spot and what is consciousness. Following the exposition of the idea and it’s proofs, I will also strive to present steps to confirm or deny what is stated here and provide a definition what is “thought” and some of what that means across various species including our own.

    Long Explanation of Functions of Nature
    There are two large, common things for which we have no explanation and unsurprisingly, they are related.

    Both Consciousness and Time are concepts that we seem to “know” a lot about but cannot define with any degree of certainty. This thesis will show that there is a geometry of Time and how it relates to consciousness, the mind and the brain.

    If you look for definitions of Time all one finds are yardsticks – measuring tools. No idea or knowledge on what exactly is Time – does it have a structure, does it have microscopic particles, what is it other than the rate of radioactive decay?

    It would be like defining the world as you perceive it in your eyes only using a ruler – sure measuring physical surfaces yield some information on those surfaces, but says little to nothing of what composes the surface or how the surface interacts with anything else other than in the most crudest fashion, nearly nothing at all about erosion, electrochemistry, friction or a myriad of other properties of the physical world as per physics.

    Basic cosmology and maths say we are living in time and space and that space can be represented in three-dimensional equations and time is a closely related fourth dimension.

    We know a lot about three-dimensional geometry from a maths perspective and have a lot of equations that can explain a lot of the structures and behaviours of the 3d world. Not so much for 4d other than describing objects moving in a 3d context.

    We have started to see some great work of mathematicians who have started to produce 4th dimensional structures in a way we can more easier perceive. A excellent development which will allow for easier understanding of the idea here – that our minds are merely the logical outcome of evolution, that time is a phenomenon part of our environment and that consciousness and our minds are simply functions of the nature of time.

    The thesis says that there is a 4th-dimensional or sub-physical landscape and that our brains evolved to the point to where we not only perceive this 4th dimension/sub-physical or quantum (misnamed and misunderstood in my opinion) aspect of the environment, – time – but can actively manipulate aspects of this time environment to achieve what we term the mind.

    We need to refine our understanding of 3D vs 4D and realize just as there are squares circles triangles cones, bricks rocks etc in 3D interacting with each other, so to there are 4D objects that interact with each other and some of these interactions produce effects we experience with our primarily 3D-evolved sensory systems. Another way of saying that is we can perceive and manipulate sub-physical or quantum aspects of our environment and this ability evolved in Nature like other aspects of organisms.

    This thesis will show how Time is perceived, what it is, how we may form nodes in Time is and how that can describe how thoughts are formed and what is memory, among other things.

    To get there, we have to refine our knowledge of evolution to understand what is an evolutionary advance using the criteria by which a mutation of an individual can be said to be better evolved than it’s peers – a successful adaptation.

    By understanding the outcomes of evolution we can see that when organisms became more complex, early nervous systems had to manage incoming sensory data about the environment within the organism itself – this ability to coordinate is in and of itself a function of time.

    Certainly there are lock and and key systems, i.e. if A is stimulated, then B will occur, methods of environmental interaction. Without these systems being present it is highly unlikely the mind would emerge at all.

    However this is only part of the story and does not explain self-awareness, problem solving and many other aspects of what we term the mind.

    When there are competing streams of data coming in to the organism that information has to be processed by the organism in a logical and beneficial fashion. Without coordination there would be a cacophony of chaos – there can be no successful organism without sensory coordination. When Time became one of those sensory experiences, consciousness arose in earnest.

    This will be supported by among others things, looking at the ability of completely different organisms to problem-solve even though they are not humans (octopi) and why; how cascades in the brain may mimic nodes or simple 4d geometry of Time; explaining what are memories (including why those with certain brain-injuries can no longer create new memories yet retain their old memories); glimpses of this through recorded history; and how synthesia can provide some proof of the thesis.’

    Just because it appears online so many are ignoring it. I released it there to honor Darwin back in 2012.

  3. Cassidy

    I applaud the article as well as the comments.
    “Few people scratch the surface, much less exhaust the contemplation of their own existence” ~ Randolph Bourne

    I want to thank you for sharing your perspective. Wisdom should always be something one wishes to gain. Therefore, I would caution anyone to rest their head on anything. From an evolutionary perspective, it doesn’t surprise me that there are only minor differences In DNA structure since every living thing comes from the same source; Amino acid. Our bodies are made up of mostly water. If you break everything down, the differences in DNA structure could be viewed as being massive. The fact that it is surprising that there there is very little difference between the chimp and human DNA structures should tell us that there is much to learn. Personally, I try viewing theories like those discussed here objectively, but also trying to understand the person who is saying it in order to view it the same way. The more I do this, the better chance I have at finding the answer. Disciplining ourselves is so important if we are to gain a philosophical advantage over another. This is why Oxford created an interdisciplinary program that includes philosophy, psychology and semantics, not just because they are so closely related but because they are pivotal to an individual’s strength-in-inderstanding.

  4. John Grandy

    In several works I have proposed and supported that DNA’s role in human consciousness has been established in three neurogenetic phases:
    1) the emergence of neuron-based consciousness
    2) the continuum of neuron-based consciousness
    3) the degeneration of neuron-based consciousness.

    Underlying this, DNA demonstrates a degree of consciousness as a dynamic system which can be objectified on three dynamic levels based on interactions:
    1) DNA-DNA interactions
    2) interactions with other nucleic entities, e.g., mitochondria-nuclear
    3) interactions between DNA and the external environment.
    Furthermore, I have also organized some of the gene families that allow DNA autopoiesis, which allow a biology of autonomy.

    Now I due understand that there is a tremendous amount of information and publications on the topic of consciousness. However, I do not understand how an article and book was published on a very specific topic on DNA and human consciousness and not one of my many works [dating from 2006 to the present] was mentioned (or debunked for that matter). Even a simple google search on “DNA, consciousness, or neurogenetics” typically yields some of my works.

  5. Bret Varcados

    3D includes our perspective of reality, 4D includes time, in5d includes consciousness.. 😉😎

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