Paul Davies has provocatively declared that the mystery of the origin of life won’t be solved by chemistry. I’m sure he’s wrong. He claims that there is a fundamental divide between information-rich, hierarchically organized biology and chemistry but much evidence shows that this barrier is illusory. Primitive cell-like membranes made of lipids are easy to make by chemical self-assembly. Once you have such a structure you have a contained environment which already has the biological, informational property: other chemicals can either be inside or outside the lipid membrane. Ribozymes, RNA molecules that can carry information and can replicate, are already primitive informational molecules. They are both enzyme and replicators and can catalyse their own replication. Finally, energy gradients are necessary for biological metabolism. Chemical energy gradients, similar to those found in the cell, have been found in open ocean environments at smokers, where hot gases emerge at high temperature from the ocean floor. Put these systems together and you can see how primitive self-replicating cells might have evolved. See Nick Lane’s Life Ascending. There are countless other areas where chemicals show self-organizing behaviour: there is a whole field of self-assembling chemistry within the ambit of nanoscience.
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