Overview of BLAST results, field measurements of temperature and pH, and model values of .

aThe number of the sampling site in the hot spring is given, together with the original letter codes used in the field to identify the samples.bThe number of inferred protein sequences in the metagenome (from JGI annotations), which in general do not correspond to complete protein sequences.cThe number of hits using protein BLAST to the microbial proteins in the RefSeq database version 57.dNumbers of major phyla (i.e. those making up at least 3% of the total number of BLAST hits in a given site) and, in parentheses, hits that are assigned to a major phylum.eField-based measurements in the hot spring [1], [19].fGradient model; calculated using Eq. 2 [19] and the values of temperature shown in this table.gCommunity model; these values minimize the difference in Gibbs energy between assemblages having the metastable equilibrium and observed relative abundances of phyla (Eq. 16).