Figure 1

Dendrograms based on Markov cluster dissimilarity in metagenomic datasets obtained for communities inhabiting (A) the outflow channel of ‘Bison Pool’ a vertical microbial mat profile from Guerrero Negro, Mexico (B) and an oceanic depth profile from the HOT- ALOHA (C). Dotted lines represent major shifts in microbial community composition: (A) transition between chemotrophic (top) and phototrophic (bottom) metabolisms, (B) transition from an oxic environment near the surface (top) to a hypoxic and sulfidic environment (bottom), and (C) transition from photic zone (top) to aphotic zone (bottom).