Integrating theory across levels of organization: from physiology to evolution

Background/Question/Methods

Making quantitative connections between lower-level processes and higher-level outcomes is a central issue in ecology. An important, and hitherto largely unresolved, issue is whether those inter-connections that occur below the level of the individuals determine those that occur above the individual level. We identify three priorities for advancing theory in ecology. The first is to develop theory that incorporates processes operating at the suborganismal level (e.g., genetic, biochemical, physiological) to predict higher-level responses to environmental perturbations (e.g., phenological and range shifts due to climate warming, population and community-level effects of toxins and pollutants). The second is to develop theory on cross-level interactions between an individual of one species and a community of others (e.g., host-microbiome interactions). The third is to develop theory, based on ideas of robustness, modularity and network motifs in suborganismal systems (e.g., transcription, metabolic and neural networks) to explain why particular network topologies confer stability at higher levels of organization such as complex ecological communities.

Results/Conclusions

We will propose novel theoretical advances on (i) integrating top-down and bottom-up approaches to modeling effects of environmental stress on organisms, (ii) predicting species’ responses to environmental perturbations by integrating information across levels of organization, from physiology to evolution, (iii) organism-community and host-microbiome interactions, and (iv) using properties of suborganismal systems (e.g., transcription, metabolic and neural networks) to predict why and how certain network topologies confer community stability and buffer the effects of environmental perturbations at community and ecosystem levels.