Interpretation and predictions of the Emergent neutrality model: a reply to Barabas et al.

Formulated in 2006, Scheffer and van Nes' Emergent neutrality model predicts that competing species might self-organize into groups of species similar in their traits. Recently, Vergnon et al. showed that the model consistently generates multimodal species abundance distributions, in accordance with empirical data. Barabas et al. argue that Emergent neutrality model relies on unmodeled, hidden' species differences. They also suggest that an Emergent neutrality model explicitly integrating such differences may fail to generate multimodal species abundance distributions, while other models can robustly produce those patterns. Here we demonstrate that density dependence - the process deemed problematic by Barabas et al. - may permanently maintain groups of similar species without need for additional species differences. More broadly, we make it clear that density dependence is not the only likely mechanism that could allow the permanent coexistence of similar species in the Emergent neutrality framework. We welcome the finding that models other than Emergent neutrality can generate multimodal abundance distributions and we briefly discuss their novelty and relevance.