title: When everything is not everywhere but species evolve: an alternative method to model adaptive properties of marine ecosystems.
abstract: The functional and taxonomic biogeography of marine microbial systems reflects the current state of an evolving system. Current models of marine microbial systems and biogeochemical cycles do not reflect this fundamental organizing principle. Here, we investigate the evolutionary adaptive potential of marine microbial systems under environmental change and introduce explicit Darwinian adaptation into an ocean modelling framework, simulating evolving phytoplankton communities in space and time. To this end, we adopt tools from adaptive dynamics theory, evaluating the fitness of invading mutants over annual timescales, replacing the resident if a fitter mutant arises. Using the evolutionary framework, we examine how community assembly, specifically the emergence of phytoplankton cell size diversity, reflects the combined effects of bottom-up and top-down controls. When compared with a species-selection approach, based on the paradigm that "Everything is everywhere, but the environment selects", we show that (i) the selected optimal trait values are similar; (ii) the patterns emerging from the adaptive model are more robust, but (iii) the two methods lead to different predictions in terms of emergent diversity. We demonstrate that explicitly evolutionary approaches to modelling marine microbial populations and functionality are feasible and practical in time-varying, space-resolving settings and provide a new tool for exploring evolutionary interactions on a range of timescales in the ocean.
authors: Environmental and Evolutionary Genomics Section , Institut De Biologie De L'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, Ecole Normale Supérieure , 46 RUE D'ULM, 75005 Paris , France ; Environmental Research and Teaching Institute (CERES-ERTI) , Ecole Normale Supérieure , 24 RUE Lhomond, 75005 Paris , France.
authors: Boris
authors: B
authors: Sauterey
authors: Environmental and Evolutionary Genomics Section , Institut De Biologie De L'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, Ecole Normale Supérieure , 46 RUE D'ULM, 75005 Paris , France ; Laboratoire Des Sciences De L'Environnement Marin , Institut Universitaire Européen De La Mer , Place Nicolas Copernic, Plouzané , France.
authors: Ben A
authors: BA
authors: Ward
authors: Department of Earth, Atmospheric and Planetary Sciences , Massachusetts Institute of Technology , Cambridge, MA , USA.
authors: Michael J
authors: MJ
authors: Follows
authors: Environmental and Evolutionary Genomics Section , Institut De Biologie De L'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, Ecole Normale Supérieure , 46 RUE D'ULM, 75005 Paris , France.
authors: Chris
authors: C
authors: Bowler
authors: Environmental and Evolutionary Genomics Section , Institut De Biologie De L'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, Ecole Normale Supérieure , 46 RUE D'ULM, 75005 Paris , France ; Environmental Research and Teaching Institute (CERES-ERTI) , Ecole Normale Supérieure , 24 RUE Lhomond, 75005 Paris , France.
authors: David
authors: D
authors: Claessen
keywords: adaptive dynamics; community; competition; eco-evolutionary dynamics; global circulation model; phytoplankton; trade-off; trait-based adaptive strategies