Strange fact number 1: Scientists trained flat worms to curl up when exposed to light by electrocuting them every time the light was turned on. A pure Pavlovian, conditioned response. Even more unfortunate for the flat worms is their ability to regenerate themselves if cut in half . An amazing thing in itself; cut them in half and the head end grows a new tail and the tail end grows a new head. When the scientists did just that they found something bizarre; when exposed to light both versions of the worm responded according to the conditioning. How can this be? Common sense and contempory neuroscience both agree that memory is contained in the brain, so how can a newly grown brain come complete with memories?
Strange fact number 2: Take a calf born of stock that is used to cattle grids but has never seen one itself and introduce it to lines painted on a road to resemble a grid. It will not cross. How has this knowledge been communicated?
Strange fact number 3: A new -born chick is placed in a room with a hawk. It frantically tries to find cover. It meets a chicken for the very first time and is completely comfortable. People would call this instinct, and I’m sure it is –but how is instinct passed from one generation to the next? Wouldn’t it have to be stored in the DNA? And instinct is just a form of memory, so if that form of memory is stored in the DNA, then why not other forms of memory. It would explain facts 1 –3 wouldn’t it?
The idea that our memories are stored in our genes is a very recent and controversial one. It has been accepted since the experiments of Wilder Penfield back in the fifties, that hidden away in each of us is a permanent record of our past. We are reminded of it regularly; how many times have you smelt a particular smell or heard a particular song, and been instantly transported back to an intense childhood memory. However, most neuroscientists believed and continue to believe that long-term memories are built into the brain by creating and strengthening connections between neighbouring neurons. These connections, known as synapses, are thought to join neurons up into complex networks that can recreate specific patterns of brain activity (memories), days, weeks, or even years, later.
There are problems with this model. These connections would need to be permanent and stable, and the brain is not. Nearly all the brain’s molecules, including those that form the neural connections thought to be involved in memory, are replaced every few weeks. How long-lasting memories can be stored by such an impermanent medium has confounded neuroscience for years. It is like writing a message on a piece of paper. Suppose we could replace the paper one molecule at a time. Eventually we would have a completely new piece of paper, with exactly the same appearance – except it would not still have the message written on it. Neurobiologist Sandra Pena de Ortiz suggests that somehow the brain must retain an archived blueprint of each neural network in order to create the replacement neuron as a structural and functional clone of its predecessor. Nature’s blueprint of choice is, of course, DNA, and it has the advantage of not undergoing the turnover that other molecules do. Not only is it quite stable over time, it even has a repair facility if anything goes wrong.
Pena believes that permanent memories are stored in altered genes. She and her colleagues believe that our DNA creates ‘memory molecules,’ new novel proteins, from a unique blueprint that could be formed by neurons rearranging their DNA in response to each new experience. The unique structure of these memory molecules would enable them to snap into a specific position at the synapses, helping make memories stable without disturbing other synaptic structures. “Changes in synaptic connections wouldn’t remain intact for long, but gene rearrangements could be kept throughout the neuron’s life.
Some scientists go even further and suggest that these memory molecules might store information themselves, that each individual neuron contains memory.
Either way this is a radical concept because the usual concept of our genetic code is of something fixed at the beginning of our lives, not something that gets re-written on a daily basis, and certainly not every brain cell being allowed to tamper with that code. But looking at it from an evolutionary point of view this arrangement does fulfil an abiding principle – that of Occam’s razor.
Occam’s razor states that nature always reduces things to the simplest solution. We know of only three ‘memory systems in nature. There is the evolutionary memory of how to build an organism; a cognitive memory of events we experience; and an immune memory of past infections. Two out of three of these are based on DNA, we would normally expect nature to be efficient enough to use the same tools for the third as well, not evolve something unique.
The impact of this theory, if true, is that our identity, our self, leaves a permanent mark on our genome. We may pass onto our descendents much more than eye colour. It has already been estimated that perhaps 40% of known personality traits are inherited, such as introversion/extraversion. This theory could explain how. It also poses other intriguing questions for our field.
Carl Jung popularised the idea of a collective unconscious that we are all plugged into, and suggested it as the repository of racial memories and universal archetypes. With genetic research now proving the inter-relatedness of all racial branches of the humanity – we are all related at some point in the past with Caesar, Sitting Bull, Nelson Mandela, Confucius and Uncle Tom Cobbly – the genetic transmission of memory would be a sensible transport mechanism for Jung’s theory. And of course we can get crazier:
If memories are stored in our DNA (and as 97% of it has no obvious function there is plenty of room), and we pass on our DNA to our children, who do the same thing with their children, could this be how the instincts of the chick and calf were passed on? If memory is stored in the genes is that how the flat worm’s tail can grow a new brain with an old memory? And finally, if they have access to instinctive memory (as we do – think of the grip response in a child when it thinks it’s being dropped), is it possible to access other ancestral memories located in our DNA? Could this be an explanation for past-life regression? When clients regress to memories from a previous life, is it actually them accessing something present in their genome blueprint, an ancestral experience?
It is the case that the mind uses past experiences as references to decide the meaning of what is occurring in the present. In the main we are used to thinking of such past experiences being limited to this lifetime. Perhaps this research opens the possibility that the unconscious has access to reference experiences stretching back generations. Certainly many people who experience such memories under hypnosis find an answer to a present problem. This would be consistent with the theory predicting that the effects of our experiences would be expressed in our genome. If this is inherited by our successors then it would also suggest that they would be subject to the consequences of those experiences. This doesn’t explain all past-life experiences – the memory of death, for example, couldn’t be explained by genetic transmission, but just because one class of experiences doesn’t fit, doesn’t render the possibility invalid.
In Cognitive Hypnotherapy we don’t treat anything as true, including any memory the client talks about; it’s simply true for them. The same would be true for past-life experiences. They might be a metaphorically more acceptable means of dealing with the issue, they might indicate a need to feel special, or the result of a highly active imagination – it doesn’t matter. What would concern us is how we can use the memory to help them let go of the problem they believe is connected to it. But it is interesting that, maybe, science is suggesting that our genes connect us to our past more vividly than we’d ever imagined.
Barry Coleman says
Trevor – your Genetic Memory Blog
Having read Richard Dawkins’ “Selfish Gene” and been very impressed I started to read your blog and was instantly on my guard.
Reading further, however, I found the ideas expressed at least plausible, mostly, and certainly interesting.
It is a real leap to suggest that an organism can change its genetic structure and a greater one to suggest that this change can be passed on to provide memories for offspring. If this capability were general then I would think that all evolutionary changes would occur much more quickly than they do. Directed evolution would throw up many extremes that would become dysfunctional. Think what would happen if induced physical development (body building, running etc) in a generation was partially passed on and reinforced by each generation; not to mention mental (brain) development.
So genetic memories acquired in a generation would need to be special and why should they be? The other two genetically based memory systems that you describe are not quite the same. The immune memory specific to a child, as far as I know, develops fresh from before birth but not directly from the mother’s genes but her own immune system. The genetic memory of how to build a body is a “given”. It happens outside of generations.
In the end, you could argue, and I would, that all genes are a memory system anyway concerned only with “remembering” how to make more survivable copies of themselves (Dawkins). This memory is in the gene, not in the body. This blueprint cannot be changed after the rocket-ship is built and launched.
There are, of course, genetic memories in all of us. Children will not crawl over the edge of a table (normally). We all “know” how to walk, and so on, with very little instruction and our lungs know how to breathe and our hearts how to beat. I often think that the genetically influenced phobias, like fear of heights for example, are more common and more intransigent.
But these are not within us because our mothers decided that heights were dangerous. They are in us because those early organisms that walked (shuffled, rolled etc) off cliffs are no longer with us. There are no chickens left that try to buddy-up with hawks for similar reasons.
The dissected worm memory is interesting also. But who knows where our memories live? I think that part of my learned memory system lies in my muscles and reflexes. Certain reflexes would probably get stronger the more they are activated. Current thinking on the brain is that generational memories are laid down by the strengthening of particular pathways and connections and this could extend to the whole body, especially in a worm, without a gene being altered.
I believe strongly that the greatest thing that our genes give us, for their own selfish purposes, is a massively complex and flexible brain (or mind) that lets each one of us adapt within a generation to an increasingly changeable environment. Our viable antecedents’ genes give us the tool and it’s up to us to use it.
Barry Coleman
Thanks for an interesting blog.
Trevor Silvester says
Hi Barry,
Thanks for taking the time to answer so thoughtfully.
I wrote this article a number of years ago, before I’d even heard of epigenetics, which I think adds further interest to the ideas.
For anyone who hasn’t come across the term: “Epigenetics is the idea that, contrary to decades of genetic theory, your genetic code isn‚Äôt the only thing that controls how your cells behave. Scientists now realize that chemicals and other environmental influences that can modify the physical structure of your DNA are at least as important as the actual genetic code. Even more surprising, these modifications are inheritable. It‚Äôs possible, for example, that your grandmother‚Äôs poor diet could affect your own health by making your DNA harder to read for the proteins that help maintain cellular functions.” (a quote form the net)
Findings from epigenetics threatens to throw a lot of conventional genetic theory into question. Results are showing quite clearly that genetic modification can happen within a lifetime, and is transmittable to succeeding generations. What we label memory could be one agency for this transmission, or an expression of it. And what would be more important information to transmit than something that aids the survival of the gene – like a near-death experience?
I don’t think we recognise cliffs as dangerous simply because all the ancestors who didn’t fell off them, I think it has been learnt from observation of others and ‘close call’ learning that was transmitted to their children.
My answer to your point about reflexes getting strengthened, is that the means by which the strength is gained would be by gene expression (something has to happpen biologically to increase the strength) , and that change, according to epigentics, could be passed on within a generation or two.
We live in interesting times. My blog on the psychobiology of suggestion uses ideas from Bruce Lipton that add to this line of thought and may interest you.
Thanks again.
Barry Coleman says
Thanks for introducing me to epigenetics.
And there I was thinking that Darwin and Dawkins had it all explained 🙂
It looks very interesting. I’ve just looked it up in Wikipedia.
I think it’s interesting that Charles Darwin’s grandfather Erasmus who proposed that organisms could develop the species by their own efforts. Giraffes stretched their own necks and made their offspring’s necks longer, for example.
Barry
Chris Parsygnat says
Usefull points written on your blog, most I agree with. Remember viewing a similar blog which I will look to post. Definately will bookmark in any case I await your next thought provoking blog post