11 January 2009

Why Life Originated (And Why it Continues)

Darwin’s 1859 classic, On the Origin of Species, doesn’t answer a very important question – how species actually originated.
In a recent study called “Why did life emerge?”, two scientists, son and father Arto Annila of the University of Helsinki and Erkki Annila of the Finnish Forest Research Institute, offer some insight into the general driving force of life’s origins in terms of thermodynamics. As they explain, all organisms are composed of molecules that assemble together via numerous chemical reactions. Just as heat flows from hot to cold, these molecules obey the universal tendency to diminish energy differences, so that the most likely chemical reactions are those in which energy flows “downhill” toward a stationary state, or chemical equilibrium.
The scientists give several examples of mechanisms associated with life that increase entropy. For instance, when systems (e.g. molecules) become entities of larger systems (e.g. cells) that participate in larger ranges of interactions to consume more free energy, entropy increases. Genetic code might have served as another primordial mechanism, acting as a catalyst that could increase energy flow toward greater entropy. Today, complex organisms have cellular metabolism, which is another mechanism that increases entropy, as it disperses energy throughout the organism and into the environment. The food chain in an ecosystem is another example of a mechanism for transferring energy on a larger scale. [source]

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