Figure 2.

Phylogeny and geographic distribution of cosmopolitan thermophilic endospores. 16S rRNA-based phylogenetic tree of thermospore phylotypes (TSPs) that were detected at 15 or more sites. Scale bar indicates 1% sequence divergence as inferred from RAxML. Phylogenetic affiliations are highlighted in different colors. Colored bars indicate broad geographic regions where the thermospore phylotypes were present. Numbers indicate the number of sites at which a thermospore phylotype was detected, whereas the height of each bar color indicates the number of those phylotypes detected in each ocean region. TSP, thermospore phylotype. See Supplementary Figure S3 for an extended tree showing the phylogeny and geographic distribution of all 146 thermospore phylotypes.