Table 2. Summary statistics for the 100 sites randomly selected for each environment.

These statistics reflect the data used for phylogenetic coarse-graining as all OTUs could be used.

Environment	Total # OTUs	Mean # OTUs	Mean # Reads
Marine	18,173	1,356.37	168,520.66
Marine sediment	41,304	4,167.25	106,166.92
Human gut	10,190	862.73	44,031.12
Human oral	7062	614.97	46,104.84
Human skin	29,448	1817.12	48,285.68
Freshwater sediment	33,193	3,569.59	65,582.56
Microbial mat	11,869	431.42	23,216.02
Freshwater	26,645	1775.89	74,298.17
Soil	45,273	4730.74	106,578.45