 by a layer of fatty acids which help stabilise the environment around the nucleic acid and help protect the all important nucleic acids. How did this fatty acid layer arise? Fatty acids are organic molecules like amino acids, and can form spontaneously in chemical soup experiments. Experiments where RNA and fatty acids are mixed together show that quite often the RNA becomes wrapped up in small bubbles of fatty acids; a simple, proto-type cell. These bubbles appear very stable and can resist high temperatures and are porous enough to let the building blocks of RNA in, but not porous enough to let RNA out. Could this have been the case for the first unicellular organisms?
Experiments such as these strongly suggest that life is a product of the basic chemistry that existed at the beginning of earth’s history. Evolutionary biology does not attempt to explain the origin of life, but chemists have come up with some excellent theories and some good supporting evidence. The key though is that as soon as life began, as soon as some flimsy molecule started to replicate, natural selection could act and evolution took over.
Written by Stephen Montgomery
edited by J. William Schopf, University of California Press: 2002