Figure 11.

The validation of the model is impossible with small sample sizes. Using the neutral model to simulate the effect of migration and source community diversity in a microbial community of 10¹⁸ individuals (e.g. a wastewater treatment plant) on (a) the number of taxa in a library of 500 clones and (b) the true local richness in a community of 10¹⁸. The number of taxa in the sample soon plateaus, which means we can infer relatively little about the local or source diversity except that both probably exceed 10³ and 10⁴, respectively. Note how the clone library species richness actually dips slightly at higher diversities, probably owing to a change in evenness in the underlying local community.