To: 2MAR$ who wrote (28897 ) 7/23/2012 10:43:41 PM From: Solon 1 Recommendation Read Replies (1) | Respond to Excellent article! Like the example of the hurricane! 8.8 Self-Organization This information is distributed among the shapes of the component molecules, and in the interaction patterns among them. The build up of this information involves a succession of stages: molecular recognition; self-assembly; self-organization; and chemical adaptation and evolution. We have already considered the first two. Let us now focus on self-organization. Lehn (2002) defined self-organization as the ‘spontaneous but information-directed generation of organized functional structures in equilibrium conditions’. The necessary information (‘coding’) for self-organization is contained in the molecular-recognition and self-assembly proclivities of the component molecules. This coding also determines how the self-assembled edifice self-organizes into a functional structure in equilibrium. For a recent survey of the various types of coding for self-organization, see my book Smart Structures: Blurring the Distinction between the Living and the Nonliving (2007). A laser is a self-organized system. Under properly engineered conditions, photons spontaneously group themselves into a configuration in which they all move in phase, resulting in a powerful laser beam. A hurricane is a self-organized system. The steady influx of energy from the Sun draws water from the oceans, as well as drives the winds. Mild tropical winds may grow into an organized configuration of a hurricane when some critical threshold is crossed. A living cell is a self-organized system, which organizes itself all the time, depending on the environment. An economy is a self-organizing system. The demand for goods and services, as also the demand for labour, constantly organizes the economy in a spontaneous way, without any central controlling authority. 8.9 Chemical Adaptation and Evolution chemical adaptation . Now suppose this set of conditions changes . This is very likely, in fact inevitable, because we are dealing with an open system. A further round of self-organization must occur, governed as always by the second law of thermodynamics. This is chemical evolution. Moreover, the set of changing conditions, i.e. the changing environment experienced by the molecules, need not necessarily be that external to the set of molecules. Even internal changes in the molecular system present a changed environment to every member of the set. And molecular configurations are changing all the time. Thus, chemical adaptation and evolution occurs in an open system of molecules (including our ecosystem) all the time. The answer is ‘yes’ because when the resources are limited, there is competition among the alternative molecular-reaction pathways, and only the fittest pathways can survive so far as consumption of precursor molecules and energy-rich molecules is concerned . Such considerations aroused special interest for explaining the origin of life-sustaining molecules. Some pioneering work in this direction was done by Melvin Calvin (1969), who introduced the idea of autocatalysis as a mechanism for molecular selection. I shall consider autocatalysis in the next article.
