Jousset, A., Eisenhauer, N., Merker, M.,Mouquet, N., Scheu, S.(2016).

Science Advances, 2, doi:10.1098/rsbl.2015.1073

Key message : We tested whether functional diversity can explain diversification patterns. We tracked the survival and diversification of a focal bacterial species (Pseudomonas fluorescens) growing in bacterial communities of variable diversity and composition. We found that high functional diversity reduced the fitness of the focal species and, at the same time, fostered its diversification. This pattern was linked to resource competition: High diversity increased competition on a portion of the resources while leaving most underexploited. The evolved phenotypes of the focal species showed a better use of underexploited resources, albeit at a cost of lower overall growth rates. As a result, diversification alleviated the impact of competition on the fitness of the focal species. We conclude that biodiversity can stimulate evolutionary diversification, provided that sufficient alternative niches are available.

Characterization of the ancestral and evolved morphotypes of the focal species at the end of the experiment. (B) Evolved morphotypes showed a more generalist resource use pattern than the ancestral strain, suggesting niche expansion during the diversification process. (C) Cumulative resource use potential of the evolved morphotypes was reduced compared to the ancestral strain, suggesting that acquisition of a new niche was accompanied by negative effects on overall resource uptake and metabolism. (D and E) Morphotypes with resource use patterns more distant from the ancestral strain showed a more generalistic resource use pattern yet a reduced overall resource use.

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OTHER TOPICS: Aesthetics of Biodiversity, Biodiversity & Ecosystem Functioning, Biogeography, Macroecology & Ecophylogenetics, Experimental Evolution, Functional Biogeography, Functional Rarity, Metacommunities, Metaecosystems, Reviews and Synthesis, Trophic Biogeography & Metaweb