Chemical evolution of nucleic acids to sustain a life of Archaea

Abstract

Archaea are a primary domain of the living kingdom, and they play an important role in biogeochemical cycles. Since the inclusion of new archaeal phylogenetic lineages in the universal tree, the origin and evolution history of this domain has been debated. To address this issue, we planned to examine the growth-associated maintenance energy and the proportion of nucleic acids in cell dry weight from 188 archaeal genomes. It was discovered that nucleotide molar fractions influenced evolutionary transmittance across archaeal phyla. At high concentrations of nucleotide molar fractions, minimal cell survivability of archaea was increased. Archaea’s survival fitness may have evolved by chemically optimizing the growth-associated maintenance energy required for nucleic acid polymerization. The chemical composition of macromolecules in an archaeal cell may have also acted as a neutral selective pressure shaping its genome dynamics and cell survivability in transient environments. The current hypothesis provides a new look at reduced growth fitness of archaea in a diverse range of environmental niches.