Fig. 2: Microbial community assembly in the gut microbiota of Atlantic cod.

The presence/absence of OTUs from Week 0 to Week 8 and Week 8 to Week 12 treatments are shaped by random microbial community assembly (at q = 0; empirical values are close to the null expectation). When we increase the importance of OTU relative abundance then assembly is shaped by deterministic processes (q ≥ 1; empirical values far greater than the null expectation). The solid lines show hill-based dissimilarity (qd) and the null expectation is shown by dashed lines. The diversity order (q) curve can be interpreted as follows; q = 0 considers OTU presence/absence, q = 1 OTUs are weighted according to relative abundance, and at q > 1 = increased weighting is given to highly abundant OTUs. Arrows at q = 0, 1, and 2 reflect the distances between the empirical dissimilarity observations and the null expectation at these key points in the diversity order curve (q). Colours reflect the pair-wise comparison tested. a shows comparisons between Week 0 and Week 8, and b shows comparisons between Week 8 and Week 12.