A recently published genomic comparison of two Salinibacter ruber strains isolated from the same location has revealed interesting insights into the process of creation of genomic variation within microbial populations (Peña et al. ISME Journal 2010). The work includes the phylogenetic analysis of the full genomic complement of both strains accross a large taxonomic scope including other sequenced bacteria and archaea. The phylome analysis has allowed the detection genes under positive selection and of putative horizontal gene transfers from Archaea that might be related to adaptaion to hypersaline environments. Interestingly some transferred genes are specifically present in only one of the strains. Some of this variations may be related to observed phenotypic differences in terms of viral resistance or adaptation to different environmental conditions. Salinibacter ruber M8 and M31 strains phylomes can be browsed in PhylomeDB