Getting from an RNA world to modern cells just got a little easier.
Our understanding of the early steps in the evolution of life is hampered by a Catch-22: Darwinian selection leading to longer genomes requires as prerequisite increased replicative fidelity. Yet a genome at capacity cannot increase in size; it will be catastrophically mutated out of existence if fidelity has not already increased. Traditionally the problem has been considered for genotypes but can be down-sized if multiple genotypes specify the same phenotype. Kun and colleagues put empirical meat on theoretical bone by analysing ribozyme mutagenesis data, concluding that modest replication fidelities could permit a primordial genome with up to 100 genes.
Poole
Anthony M
AM
Department of Molecular Biology and Functional Genomics, Stockholm University, SE-106 91 Stockholm, Sweden. anthony.poole@molbio.su.se
D005075:Biological Evolution; D002477:Cells / Q000166:cytology / Q000378:metabolism*; D016678:Genome; D005838:Genotype; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D000069497:Origin of Life; D010641:Phenotype; D012313:RNA / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D016337:RNA, Catalytic / Q000235:genetics / Q000378:metabolism
D016337:RNA, Catalytic; D012313:RNA