  The homochirality of the molecules of life has been a vexing problem with no
generally accepted solution to date. Since a racemic mixture of chiral
nucleotides frustrates the extension and replication of RNA and DNA,
understanding the origin of homochirality has important implications to the
investigation of the origin of life. Here we suggest a novel solution to the
homochirality problem based on a recently proposed thermodynamic dissipation
theory for the origin of life. Homochirality is suggested to have been
incorporated gradually into the emerging life as a result of asymmetric right-
over left-handed photon-induced denaturation of RNA/DNA occurring when Archean
sea surface temperatures became close to the denaturing temperatures of
RNA/DNA. This differential denaturing success would have been promoted by the
somewhat right-handed circularly polarized submarine light of the late
afternoon when surface water temperatures are highest, and a negative circular
dichroism band extending from 220 nm up to 260 nm for small segments of
RNA/DNA. A numerical model is presented demonstrating the efficacy of such a
mechanism in procuring 100% homochirality of RNA or DNA from an original
racemic solution in less than 500 Archean years assuming a photon absorption
threshold for replication representing the hydrogen bonding energies between
complimentary strands. Because cholesteric D-nucleic acids have greater
affinity for L-amino acids due to a positive structural complementarity, and
because D-RNA/DNA+L-amino acid complexes also have a negative circular
dichroism band between 200 - 300 nm, the homochirality of amino acids can also
be explained by the theory.
