THE CONCEPT OF PARITY IN NUCLEOTIDES: IMPLICATIONS FOR THE EXISTENCE OF LIFE BASED ON ALTERNATIVE ALPHABETS

摘要

The possibility of life based on biochemistries essentially similar to our own, yet employing amino-acids with D-stereochemistry, or perhaps L-sugars, is well recognized. In this paper a further division of potential biochemistries, based on the recently recognized property of nucleotide parity, in the computational or informatics sense of the word, is proposed. Viable alphabets, for reasons of replication fidelity, must be composed from nucleotides of like-parity only. The nucleotides of the natural terrestrial alphabet have "even" parity. However, from an informatics perspective, an alphabet composed from "odd"-parity nucleotides is equally viable, suggesting the possibility of life based on nucleotides with a digital parity opposite to our own.