  We propose a scenario for the prebiotic co-evolution of RNA and of fast
folding proteins with large entropy gaps as observed today. We show from very
general principles that the folding and unfolding of the proteins synthesized
by RNA can function as a heat pump. Rock surfaces can facilitate the folding of
amino acid chains having polar and hydrophobic residues, with an accompanying
heat loss to the surrounding rock. These chains then absorb heat from the soup
as they unfold. This opens the way to the enhancement of RNA replication rates,
by the enzymatic action of folded proteins present in greater numbers at
reduced temperatures. This gives an evolutionary advantage to those RNA coding
amino acid sequences with non-degenerate folded states which would provide the
most efficient refrigeration.
