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1.
Am Nat ; 190(1): 116-130, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28617645

RESUMO

Models of community assembly have been used to illustrate how the many functionally diverse species that compose plankton food webs can coexist. However, the evolutionary processes leading to the emergence of plankton food webs and their interplay with migratory processes and spatial heterogeneity are yet to be explored. We study the eco-evolutionary dynamics of a modeled plankton community structured in both size and space and physiologically constrained by empirical data. We demonstrate that a complex yet ecologically and evolutionarily stable size-structured food web can emerge from an initial set of two monomorphic phytoplankton and zooplankton populations. We also show that the coupling of spatial heterogeneity and migration results in the emergence of specific biogeographic patterns: (i) the emergence of a source-sink structure of the plankton metacommunities, (ii) changes in size diversity dependent on migratory intensity and on the scale at which diversity is considered (local vs. global), and (iii) the emergence of eco-evolutionary provinces (i.e., a spatial unit characterized by some level of abiotic heterogeneity but of homogenous size composition due to horizontal movements) at spatial scales that increase with the strength of the migratory processes.


Assuntos
Evolução Biológica , Cadeia Alimentar , Plâncton , Animais , Fitoplâncton , Zooplâncton
2.
Am Nat ; 189(2): 170-177, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28107051

RESUMO

Rates of metabolism and population growth are often assumed to decrease universally with increasing organism size. Recent observations have shown, however, that maximum population growth rates among phytoplankton smaller than ∼6 µm in diameter tend to increase with organism size. Here we bring together observations and theory to demonstrate that the observed change in slope is attributable to a trade-off between nutrient uptake and the potential rate of internal metabolism. Specifically, we apply an established model of phytoplankton growth to explore a trade-off between the ability of cells to replenish their internal quota (which increases with size) and their ability to synthesize new biomass (which decreases with size). Contrary to the metabolic theory of ecology, these results demonstrate that rates of resource acquisition (rather than metabolism) provide the primary physiological constraint on the growth rates of some of the smallest and most numerically abundant photosynthetic organisms on Earth.


Assuntos
Modelos Biológicos , Fitoplâncton/crescimento & desenvolvimento , Biomassa , Ecologia , Fotossíntese
3.
Ecol Evol ; 6(21): 7717-7726, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30128123

RESUMO

Most top impact factor ecology journals indicate a preference or requirement for short manuscripts; some state clearly defined word limits, whereas others indicate a preference for more concise papers. Yet evidence from a variety of academic fields indicates that within journals longer papers are both more positively reviewed by referees and more highly cited. We examine the relationship between citations received and manuscript length, number of authors, and number of references cited for papers published in 32 ecology journals between 2009 and 2012. We find that longer papers, those with more authors, and those that cite more references are cited more. Although paper length, author count, and references cited all positively covary, an increase in each independently predicts an increase in citations received, with estimated relationships positive for all the journals we examined. That all three variables covary positively with citations suggests that papers presenting more and a greater diversity of data and ideas are more impactful. We suggest that the imposition of arbitrary manuscript length limits discourages the publication of more impactful studies. We propose that journals abolish arbitrary word or page limits, avoid declining papers (or requiring shortening) on the basis of length alone (irrespective of content), and adopt the philosophy that papers should be as long as they need to be.

4.
J Plankton Res ; 37(1): 28-47, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25852217

RESUMO

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.

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