Table 1. Enrichment of the significant 16S eigenpositions in taxonomic groups.

Eigenposition	Correlated				Anticorrelated
	Taxonomic Group	j	J	P-value	Taxonomic Group	j	J	P-value
2	Eukarya	75	107		Bacteria	75	175
	Microsporidia
3					Archaea	57	57
					Microsporidia
4	Gamma	32	32		Actinobacteria	72	74
	Proteobacteria				Archaea
5	Microsporidia	29	36		Archaea	21	21
6	Fungi/Metazoa	32	32		Rhodophyta	26	26
	Microsporidia
7	Alveolata	21	21		Fungi/Metazoa	32	32
					Microsporidia

Probabilistic significance of the enrichment of the k = 75 organisms, with largest relative nucleotide frequency increase or decrease in each of the significant eigenpositions, in the respective taxonomic groups. The P-value of each enrichment is calculated as described [35], assuming hypergeometric probability distribution of the J annotations among the K = 339 organisms, and of the subset of annotations among the subset of k = 75 organisms.