Stratigraphy of SPAIN and beyond - history, monuments, ideas, arts & crafts

domingo, 6 de junio de 2010

The DNA is not coding!

(Scientific metaphors in everyday language - Part II)

life versus machines
Let us start comparing living organisms with man-made production systems such as machines, hardware or software (HW/SW). In spite of many similarities between these two kinds of systems ( "input", "output", "information or material processing", "communication" etc) there are fundamental differences. The most important distinction is probably that there is always a clear purpose of a machine or a program, while the "final product" of a living system is.... itself! Consequently the existence of a living system does not have a pre-set "purpose" or "meaning" in the same way as any man-made production system does always have.
If the living system is a human being, the "meaning of life" is created by the person, for him/herself, in a complex kaleidoscope of actions including learning, experiences, interpretations, interactions with others, decisions, small or bigger personal sacrifices, etc.
This might seem as an idea belonging to "soft" sciences only (philosophy, psychology, theology); but I believe it is fairly relevant in a broader context. Why?
Because our entire thinking is dominated by metaphors: concepts transferred from one domain of knowledge to other. Use of metaphors is unavoidable and enriching, as discussed in part I, my January 2009 blog entry on the metaphor of crystallization, but should always be supervised critically.

the DNA as metaphor
In the last decades more and more words and concepts from HW/SW have been transferred to living systems and then broadly divulgated. For me the most striking is the term "coding" for what the DNA molecule "does". Nowadays it is difficult to open a magazine or newspaper without finding an advertisement or article using the metaphor of "our DNA" applied to some kind of basic principle governing conduct or business.
The two step "implementation" here goes: first the word "coding" went from machines to biology, then from life science to the adverts. I am claiming that already the first step is highly problematic, and therefore the second is pure nonsense. Let me try to explain.


Originally, a code is a sequence of information inserted in a system by human intelligence, and there it does things it is meant to do. Hence there is strong relation between "coding" and "controlling".

the DNA as actor in the cell
Trying to use neutral words, what is exactly the role of the DNA inside a cell? Well, the information stored in the sequence of building blocks in the DNA molecule is translated to the sequence of building blocks of proteins. But by calling this information transfer for "coding", we automatically introduce the idea of control, which is a wrong one: Within a cell, the DNA is not controlling anything; if we have to talk about control on the micro level of life, the actors are sugars, ions, hormones and other molecules floating in the cytoplasm (the jelly inside the cells) or in the blood; and not even these individual molecules rather their concentrations.
We can not isolate a component of an integral living system, assigning it the role of "the boss", just because it has long term storage of information. This idea of the "boss molecule" in the center of the cell seems to be very popular, specially among journalists, but it is simply not reflecting reality.

breaking the code?
Let us now regard other aspect of man-made codes: by deciphering a code we can go back to the meaning inserted by the intelligence that created it. This popular motive is forming the core of many bestsellers and Hollywood movies. For instance in wartime the secret messages are sent as a code to inhibit immediate understanding by the enemy, when receiving/capturing such a message it need to be deciphered; Or artists in ancient cultures leaving hidden messages in their works, a kind of code that needs to be interpreted. Others again believe in additional secret messages in the Bible etc. etc.
Here is the second danger of regarding the DNA as a code. It introduces a false idea of "reaching the meaning by deciphering". Even if the DNA molecule is not created by man, and obviously it does not include a secret message, there is a kind of semi-religious expectation bound to the mapping of the human genome; like if it could reveal us one day The Meaning of Life.
Sorry to disappoint, but it will never do so! As said in the beginning of this essay, there is no magic formula; the meaning of life is not pre-defined but must be created individually, consciously and continuously by each and every one of us.

the selfish DNA?

Of course I am aware of the DNAs role in bearing hereditary information from one generation of individuals to the next, but this alter nothing on the above line of argumentation. We have each our luggage of inherited genetics to live with and to pass to our kids, and that’s it. Just another part of our horizon - along with our education, culture, friends, family... Richard Dawkins’ idea of genes "using" the individuals as vehicle is pure abstraction, an excellent mind game but absolutely useless from an "practical - existential" perspective.

to summarize: A code has a pre-defined meaning and can have a controlling function. The DNA molecule is nor controlling nor has a pre-defined meaning.
A concept like "Control through basic principles" does exist in nature, but can not be reduced to the three-lettered-name of a molecule; how attractive this idea might be. Hence when the DNA is used as metaphor for "coding" we are introducing a bias in our language and thinking.


My personal recommendation is to avoid the use of this metaphor.

So the DNA is nor coding, nor controlling nor hiding secret messages. Reasonably enough my dear reader might ask what everyday expression could then be assigned as "summary" of the activity of this molecule?
It is ordering and keeping up order.
These were also the key words when we were talking of the process of crystallization - not a coincidence! Actually the molecule was described as a "one dimensional crystal" by Erwin Schrödinger before it was known as "DNA", i.e. before its structure was known.


In a future entry I will continue meditating in this direction.

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