Fig. 3

Alpha- and betadiversity analyses of the polar and Tara Oceans microbiomes. a Chao1, Shannon, and Simpson diversities were calculated based on miTags normalized to the same library size (10,000 sequences per metagenome). b Jaccard similarity of the microbial communities illustrated by principal coordinates analysis of the OTU matrix (item and tag numbers). This analysis was performed after normalizing the miTags data to the same library size (10,000 sequences per metagenome). The six groups: Arctic-Surface (0-100 m), Arctic-Deep (200-4000 m), Antarctic-Surface (0-100 m), Antarctic-Deep (200-4000 m), Tara-Surface (5 m), and Tara-Deep (100-1000 m)