Table 1. Random Forest results by taxonomic group and environment type.

The columns show the accuracy and out-of-bag (OOB) error for predicting each environment type. Out-of-bag error is an estimation of the prediction error of Random Forest computed by testing each tree against data not used in building that tree.

	Environment Type
Domain	Gut	Coastal Marine	Freshwater	Soil
Bacteria
Accuracy	0.982	0.984	0.97	0.985
OOB error	0.022	0.026	0.052	0.0174
Archaea
Accuracy	0.966	0.977	0.966	0.98
OOB error	0.0497	0.062	0.049	0.021
Eukaryota
Accuracy	0.955	0.967	0.959	0.984
OOB error	0.047	0.062	0.066	0.034
Viruses
Accuracy	0.964	0.927	0.96	0.965
OOB error	0.054	0.061	0.058	0.027