not-yet-known not-yet-known not-yet-known unknown Early ecological theory predicts that complex ecological networks are unstable and are unlikely to persist, despite many empirical studies of such complexity in nature. This inconsistency has fascinated ecologists for decades. To resolve complexity-stability relationships, coupling population dynamics and trait dynamics is considered to be an important way to understand the long-term stability of ecological community assemblages. However, incorporating adaptive processes into ecologically realistic networks with both antagonistic and mutualistic interactions is still a challenge. Here, we explored an adaptive food-web model to evaluate how the evolution of foraging preference (behaviour trait) to determine the relationship between network complexity (e.g., connectance) and stability (e.g., community persistence) in a multiplex community with multiple interaction types (MEST: mutualist-exploiter-specialist predator-top predator). Our theoretical results showed: (i) adaptive foraging of the top predator contributes to the stability of mutualism and intermediate intensity of foraging adaptation can lead to chaotic dynamics in a four-species MEST community; (ii) the connectance-stability relationship may show positive monotonic, negative monotonic, peaked and double-peaked patterns in general MEST communities, while the double-peaked pattern is only obtained when both the adaptation intensity and interspecific competition are high. Moreover, we infer that foraging adaptation of the top predator may alter positive and/or negative feedback loops (trait-mediated indirect effects) to affect the stability of the MEST community. Finally, our theoretical predictions may be consistent with both the negative monotonic complexity-stability relationship revealed in freshwater communities and the peaked pattern revealed in marine communities. Our adaptive dynamics framework may provide an effective way to address the complexity-stability debate in real ecosystems.

Explaining how cooperative individuals positively assort into a cohesive community is one of the greatest challenges for evolutionary biology. Here, we show that in antibiotic culture, many and even all of Escherichia coli bacteria cells will plastically mutate to be antibiotic resistant with the increase of antibiotic concentration and then altruistically protect antibiotic-sensitive individuals from the attack of antibiotics. A further experiment showed that antibiotic-sensitive E. coli strain could in turn help reduce the indole produced by the resistant strain;whistthis metabolic product is harmful to the growth of the antibiotic-resistant strain but benefits the antibiotic-sensitive strain by helping turn on the multi-drug exporter to discharge the antibiotic. A reciprocal cooperation can therefore evolve via a non-positive exchange between the metabolism byproduct indole of antibiotic-resistant cells and the indole-aborting service of antibiotic sensitive cells as unconscious help in nullifying indole side effect of antibiotic resistant strain.

Predicting how warming-induced shifts in plant species-specific phenology affect species dominance remains challenging. Here, we investigated the effects of experimental warming on plant species-specific phenology and dominance as well as their relations in an alpine meadow on the Tibetan Plateau. Warming significantly advanced phenological firsts (leaf out and first flower dates) for most species, while having variable effects on phenological lasts (leaf senescence and last flower) and full phenological periods (growing season and flower duration). Experimental warming reduced community evenness and differentially impacted the species-specific dominance. Specifically, warming-induced shifts in phenological lasts and full phenological periods, rather than the single phenological firsts, are associated with changes in species dominance. Species with lengthened full phenological periods under warming increased their dominance. Our results advance our understanding of how altered species-specific phenophases can be related to changes in community structure in response to climate change.