Figure 6.

Proportion of assemblies carrying genes for redox traits. A) Proportion for all assemblies carrying the gene for NirS or NirK, or the proportion of assemblies within each clade carrying the genes for the associated function in the B) NirS and C) NirK phylogenies. Shading indicates the fraction of assemblies represented in the reference phylogeny which have the gene or trait of interest. Asterisks denote traits with a greater than expected frequency within a clade based on chi-squared post hoc tests. Grey indicates the trait was not tested due to not being found in members of any clade in the corresponding phylogeny. NirK clades 1b and 1g are not shown because they consist exclusively of eukaryotes and lack reliable protein predictions, while NirS clade 4 is excluded because it consists of just two taxa. nir^* refers to nirS when discussing assemblies carrying NirK and nirK when discussing assemblies carrying NirS. Assemblies carrying both nirK and nirS genes were excluded from panel A and are shown in Table S8. Genes used as markers for each trait are listed in the Supplementary Methods.