Tuesday, July 31, 2007

Correlation vs. Causation - DNA and Epigenetics


Correlation and Causation seem to me to be two of the most commonly confused terms in the modern world. Nowhere is this more apparent than in the reporting and interpretation of genetic research.

I got only 50 pages into 'The Biology of Belief' by Bruce H. Lipton and already was in love. It is rare that a scientists views of the world truly resonate with my own interpretations. I have long argued that DNA as a causative factor in our lives is a confused and partial truth. I occasionally read of studies that point at this, but far too often the opposite conclusion is drawn. 'My genes made me fat, caused my cancer, leave me crippled with ADD, depression, chronic fatigue, addiction, obesity, etc. and there is ultimately little that I can do.'

The fact that there is some truth in this does not mean that we are powerless, quite the opposite I think.

Lipton makes some very important points early on '...genes can not turn themselves on or off...genes are not "self-emergent". Something in the environment has to trigger gene activity.'. So our genes certainly speak of (often latent) potentials, but they alone can not be studied to tell us why we are as we are. (p26)

Later Lipton gives us the analogy of the belief that keys 'control' cars. If one were to study all cars that are moving (much as geneticists may study all people with cancer) in an attempt to determine causes of this 'movement' phenomenon they may well find that all moving cars contain keys. They may even go so far as to look and find no stationary cars containing keys. Does this mean that keys control cars or cause them to be moving? Obviously not, they are correlative, not causative. (p50) There are other environmental and interior factors at work here as well (driver, gas, battery charge etc). DNA (keys) may very well be the newest and most fundamental factor to receive sciences attention, but how is it that this leads us to ignore or belittle the myriad other factors at play? And more importantly, how useful is this towards empowering us to make positive change?

Mr. Lipton goes on to point out Darwin's late life realization: "the greatest error which I have committed has been not allowing sufficient weight to the direct action of the environments, I.e. Food, climate, etc., independently of natural selection."

"When a gene product is needed, a signal from its environment, not an emergent property of the gene itself, activates expression of that gene." - H. F. Nijhout (p52)

Lipton also points out that, while it holds a wealth of information and can rightly be considered a warehouse of potentials, DNA alone does not interact with the environment to determine our response to stimulus. "In the chromosome, the DNA forms the core, and the proteins cover the DNA like a sleeve. When the genes are covered, their information can not be "read".(p67) What causes the protein 'sleeve' to roll back and allow the DNA to express itself? Environmental signals. So, it would seem that in many ways the regulatory proteins surrounding our DNA are deciding which potentials we will express, and when, more than the DNA that is getting so much media attention these days. Lipton even points out that more often than not, in an attempt to get at and study DNA, the proteins surrounding it are removed and discarded. Is this because DNA houses all of the necessary information for the life that is me?

Consider that our bodies are made up of over 100,000 different proteins. "Conventional thought held that the body needed one gene to provide for each of the 100,000...Add to that 20,000 regulatory genes, which orchestrate the activity of the protein-encoding genes. Scientists concluded that the human genome would contain a minimum of 120,000 genes." (p62) But it turns out that they found closer to 25,000. The spineless, thousand-celled Caenorhabditis worm has 24,000. Obviously there is more at work here building each of us than just DNA.

Epigenetics - Control above genetics

Epigenetic research is now showing us that, not only is there a lot more to our complexity than DNA can account for, the whole process is a lot more fluid than previously believed. Epigeneticists are the scientists who keep the regulatory proteins and study them when breaking open a cells nucleus to get at its contents (DNA and regulatory proteins). These are the scientists who are teaching us that the holy grail of building life is not DNA-->RNA-->protein, but Environmental Signal<-->Regulatory Protein<-->DNA<-->RNA<-->Protein. Notice that the arrows actually go in both directions. 'DNA blueprints passed down through genes are not concrete at birth'. They change!!! They respond!

Yes, this does seem to imply that the outside world, and our interactions with it can actually rewrite our genetic code. Is this actually surprising? Does the idea of 'random mutation' followed by 'natural selection' really make more sense? What does the word random usually imply in a scientific context? It usually means 'we have no fucking clue what is happening, and are not going to admit any attempts to figure it out'. Thank god someone did.

In attempting to explain what I view to be one of our current limitations when attempting to understand what DNA, RNA, proteins etc. are and how they interact with the world I have come up with a train analogy:

Picture the human mind/body as a train. Let's say that science wants to know what's happening inside of the train in order to determine where that train will end up, and in what condition. So science decides that people control trains. Science then finds a way to capture a static image of the entire contents of the train, who is in it, what they are saying, what their plans are, etc. Science then spends a great deal of time studying the content of that one image and comparing its findings to similar snapshots of information gathered from other trains. What science can not yet honor is that the train is full of holes and its contents change over time. Windows and doors open and close both as the train stops and when it is in motion. The train made many stops before the image was captured and has made many more stops since the image was captured. Most likely it was making stops or had windows open while the image was being captured. And what is happening at these stops and through these openings? People are getting on and off, they are smelling the air outside, breathing its contents, hearings it's sounds. The environment around the train is permeating and changing the contents of the train and vice versa. The conversations that the passengers on a train are likely to have rest heavily on where the train is, who has entered, exited, and who is being mesmerized by the sights out the window. The train may have a schedule, and should environmental conditions be one particular way, it may even follow that schedule to the mili-second with no malfunctions or mishaps, but neither this schedule nor the people on the train at the time of the imaging are necessarily causative. They are correlates. And not one piece of this ever changing information can be looked at in a deterministic fashion if we really want to have a clue how that train is going to end up.

We currently have the capability to sequence the entire human genome (It's still really fucking expensive) and have done it quite a few times. I am not aware of any comparative studies that attempt to look at the human genome at birth, death, and at many intervals in between. I suspect that we will see differences. I do not believe that our genetic code is static or causative. We are a product of our genes, our proteins, our community, our society, and, as Mr. Lipton states clearly in other sections of the book, of our beliefs as well.

What is beautiful about all of this is that the idea that we need to dominate (survival of the fittest) or control others so that we can survive just doesn't make sense when it is precisely those others whom we rely on for all of the growth that we have ever made. It seems as if by nurturing our environment we are actually nurturing ourselves.

What is the impact of all this? Not that survival of the fittest is necessarily 100% wrong, but that it is certainly not the whole truth either. There may be more value in cooperation with our environment (others) than previously imagined. There's really no reason to feel trapped and scared, as if the environment is out to get you and you are ill prepared to meet it. We are being created by it. We are creating with it. We are perfectly in sync with it. The imaginary lines that we have drawn around ourselves, separating self from other, are melting every day.

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