A modeling preprint suggests that near-perfect correlations between species are not a universal sign of ecological instability; the signal depends on whether a slowly relaxing mode is visible above background fluctuations.
A new arXiv preprint develops models in which reproduction and survival favor different trait values and their selection strengths vary across space or time. The analysis predicts shifted optima, asymmetric or potentially two-peaked effective fitness landscapes, and wider or displaced distributions of simulated trait outcomes.