What is self-organization and what has it got to do with origin of life?

Self-organization, also called spontaneous order, is a process where some form of overall order arises from local interactions between parts of an initially disordered system. The process can be spontaneous when sufficient energy is available, not needing control by any external agent. (Wikipedia)

It has been used in support of abiogenesis. Some believe that the specific sequence of amino-acids in proteins can be explained by the self-organization law.

Can chemistry explain information in DNA? A critique of self-organization.

The third approach that I mentioned for explaining the origin, well explaining anything according to Jacque Minogue is an approach that relies on pure necessity or natural law or what in origin of life studies became known as self-organization. And there have been a number of these theories but perhaps the first and most prominent theory was attempting to explain precisely the sequence specificity of proteins and other critical molecules in the cell. And the idea behind it was that just as in a crystal of salt there is a force of attraction, a chemical force that is responsible for the beautiful ordering of a of the crystalline structure that you often find was salt. NA has a plus charge, CL a minus charge, plus and minus attract, you get a beautiful matrix that develops. That’s a self-organizing process produced by chemical attraction. And the idea that was first put forward and his first self-organizational theory was put forward by a man named Dean Kenyon and his co-author Gary Steinman in a book called Biochemical Predestination. We have a professor here tonight from Calvin College so I probably need to clarify this is biochemical predestination not the Calvinistic kind. Ok the idea here is that you’ve got forces of chemical attraction that are responsible for the sequential arrangement of the amino acids that allows the protein to fold into its right structure and perform a function in the cell. 

There was also the hope that perhaps this idea could be applied to explain not only the sequence specificity in proteins but also in DNA and RNA as well. Well it turned out that this model unraveled and the chief architect of the model himself ended up repudiating his own theory and there’s a kind of many-step story associated with this which I tell in the book but I want to zero in on the problem of trying to explain the origin of information in DNA by reference to any kind of self organizational forces of attraction. Dean Kenyon realized quickly there was some empirical results that showed that his idea wasn’t going to work for proteins. There were some slight differences of affinity between some amino acids and others but they didn’t correlate to any of the known sequencing in actual proteins. But in a more fundamental level he realized that self organization is going to work, it’s got to explain the origin of DNA and RNA because those molecules provide the information for building proteins. That’s the more fundamental need in explanation.

So I have behind me a diagram and I wish I had a pointer. This is the structural formula for the the DNA molecule and I want you to notice a few things. For non-chemists here it’s going to sound like Chinese at first but stay with me here along this. The two sides of the DNA molecule are made of something called the sugar phosphate backbone. The pentagons are the sugars, the circles are the phosphates and the backbone of the molecule is not the informational part of it; it’s the medium upon which the information is inscribed, if you will. Along the interior of the molecule are two copies running in opposite directions of the informational instructions. They’re encoded using those bases that I discussed at the beginning of the evening the A’s C’s G’s and T’s, also known as nucleotide bases. Now it’s the specific arrangement of those nucleotide bases that constitutes the information in the DNA molecule.

Now the question is: could you explain the specific arrangement of the bases by reference to self-organizational forces of attraction? Could chemistry explain that information? Now there are little sticks that you can see on my figure and the sticks represent chemical bonds, connection points where there is a force of attraction holding something together. Notice that there are sticks between each of the sugars and phosphates. Notice that there is a bond as well between each of the bases and the pentagons in this sugar phosphate backbone. But notice that there are no bonds between the bases in the information bearing axis, the vertical axis of the molecule on the screen there. There are no forces of attraction whatsoever. It’s not a matter of “Are there forces that are differential in strength or otherwise? It’s just that there are no bonds between those bases, no bonds that could explain their specific arrangement. Notice also that you have a bond between the base and the pentagons but here’s another little fact that you need to know. It’s the same kind of chemical bond in each case. It’s called an englycosidic bond for chemists who are keeping score back home and if that bond allows any one of the four bases to attach to the backbone with equal facility. It doesn’t discriminate. 

Now that was all probably difficult but I’m now gonna make it simple. I’ve got a little visual aid here with a message pandering to the local audience.  La Mirada rocks. Sometimes I put a Z in there because my students told me that made it even more cool. You might recognize a magnetic chalkboard. This is a little metallic chalkboard and there are magnets in the back of these letters so there are forces of attraction – forces of necessity if you will – that explain why the message sticks to the medium. Now that’s exactly the same, that’s exactly what’s going on in DNA. There are forces of attraction that explain why the message sticks to the medium but those forces of attraction don’t discriminate. I can put the L here, here or here anywhere I like okay. And notice that those forces of attraction do not determine the arrangement. I can destroy this arrangement and make another one very easily. Let’s talk about the message I had at the beginning. Was the message I had at the beginning the result of the magnetism? Okay that’s the key point. Let’s go back to that DNA picture. If you look at the DNA molecule, the point I’m making about the DNA is that the arrangement of the bases which constitutes the informational endowment of the DNA molecule is not the result of the chemistry attraction that holds the the molecule together.