Roth Edward Conrad

Abstract Surveys of microbial communities (metagenomics) or isolate genomes have revealed sequence-discrete species. That is, members of the same species usually show >95% Average Nucleotide Identity (ANI) of shared genes among themselves vs. <83% ANI to members of other species while genome pairs showing between 83-95% ANI are comparatively rare.

Abstract Recent analyses of metagenomes and genomes have revealed that microbial communities are predominantly composed of persistent, sequence-discrete species and intraspecies units (genomovars). To advance the species concept the underlying genetic or ecological mechanisms that maintain these discrete units need to be elucidated.

Abstract Despite the importance of intra-species variants of viruses for causing disease and/or disrupting ecosystem functioning, there is no universally applicable standard to define these. A 95% whole-genome average nucleotide identity (ANI) gap is commonly used to define species, especially for bacteriophages, but whether a similar gap exists within species that can be used to define intra-species units has not been evaluated yet.