Bacterial species and evolution: Theoretical and practical perspectives

Adaptation and incipient sympatric speciation of Bacillus simplex under microclimatic contrast at “Evolution Canyons” I and II, Israel

“…1 a and b) and their genetic similarity on either African-like or European-like slopes of both canyons (Fig. 2 e and f ) is best explained by migrational exchange, which is expected for Bacilli because of spore dissemination (9,13). Yet, despite the high equalizing factor of migration, certainly higher within (100-400 m) than between canyons (40 km), the B. simplex interslope divergence within a canyon is by far higher than for the same slopes across canyons ( Fig.…”

“…Notably, under the current prokaryotic species concept (50, 51), all evolutionary lineages described here, considered by us as true evolutionary species, would have been pooled to one taxonomic species (43). However, this pragmatic and applicable concept lacks a theoretical basis and does not refer to the evolutionary processes of adaptation and speciation due to ecological divergence (52)(53)(54). Here, our data add to the endeavors of developing a theory-based prokaryotic taxonomy (55).…”

“…The aberrant uvrA gene sequence of lineage Ba could perhaps be such an example. Second, it could blur and retard to various extents the divergence of genomic lineages by frequent gene shuffling (52). The linkage disequilibrium analyses of the gapA, pgk, and uvrA genes suggest some influence of parasexual recombination in the B. simplex metapopulation.…”

“…Some studies focus on world-wide populations, with less emphasis on local dynamics (9,10); others focus entirely on very localized populations (11,12), thereby neglecting migration and geographical distance. Some studies refer to local and global populations but focus on populations from highly similar (13) or very different types of habitats (14,15). This procedure impedes linkage of varying geographical distance to varying ecology.…”

Bacillus sonorensis sp. nov., a close relative of Bacillus licheniformis, isolated from soil in the Sonoran Desert, Arizona.

“…These strains were identified as B. Duncan et al (1994) from a site on Tumamoc Hill (the second alternative designation for each such strain was used by Istock et al, 1996) Phenotypic characterization. Physiological, morphological and metabolic characteristics (except pigmentation and fatty acid composition) were determined as described previously (Gordon et al, 1973 ;Nakamura & Swezey, 1983).…”