FIG. 2.

Contig size distribution for assemblies of around 100 Mbp of Sanger data obtained from each of seven microbial communities. The gray area indicates small contigs with a higher likelihood of chimeric assemblies (see “Assembly”). Communities with contigs found mostly in this zone (termite hindgut [146], soil, and whale fall [135]) lack dominant populations, whereas communities with larger contigs outside this zone have dominant populations: gutless worm (150), phosphorus-removing sludges from U.S. and Australian (OZ) laboratory-scale bioreactors (47), and an acid mine drainage (AMD) biofilm (138). Note that the gutless worm scaffolds (end-pair-linked contigs) are shown, explaining the larger size.