Are fluctuating phases in microbial microcosms the chaotic phase of theory?
In plain words
Laboratory communities of bacteria change from stable coexistence to lasting population swings as more species are added or as they interact more strongly, as random-interaction models predict. It remains to be shown that the experimental swings are the same phase the theory describes, rather than a different effect.
Precise statement
Microcosm experiments that vary species-pool size $S$ and effective interaction strength find stable full coexistence, stable partial coexistence and persistent fluctuations, ordered as in random Lotka-Volterra theory. Determine whether the fluctuating experimental state shows the signatures of the theoretical chaotic phase: positive Lyapunov exponent from time series, self-consistent noise statistics of abundances, and phase-boundary location $\sigma_c(\gamma)$ set by measured interaction statistics. An answer is a quantitative match or mismatch with these predictions.
What would settle it
Long, densely sampled time series of replicated microcosms with measured pairwise interaction statistics, compared with mean-field predictions for the boundary and fluctuation statistics.
Status in the literature
2022 microcosm experiments mapped the three phases with the order predicted by random-interaction theory.