Eco-evolutionary dynamics: intertwining ecological and evolutionary processes in contemporary time

Evolution occurring over contemporary time scales can have important effects on populations, communities, and ecosystems. Recent studies show that the magnitude of these effects can be large and can generate feedbacks that further shape evolution

A unifying framework for understanding ecological and evolutionary population connectivity

Although the concept of connectivity is ubiquitous in ecology and evolution, its definition is often inconsistent, particularly in interdisciplinary research. In an ecological context, population connectivity refers to the movement of individuals or species across a landscape. It is measured by locating organisms and tracking their occurrence across space and time. In an evolutionary context, connectivity is typically used to describe levels of current and past gene flow, calculated from the degree of genetic similarity between populations. Both connectivity definitions are useful in their specific contexts, but rarely are these two perspectives combined. Different definitions of connectivity could result in misunderstandings across subdisciplines. Here, we unite ecological and evolutionary perspectives into a single unifying framework by advocating for connectivity to be conceptualized as a generational continuum. Within this framework, connectivity can be subdivided into three timescales: (1) within a generation (e.g., movement), (2) across one parent-offspring generation (e.g., dispersal), and (3) across two or more generations (e.g., gene flow), with each timescale determining the relevant context and dictating whether the connectivity has ecological or evolutionary consequences. Applying our framework to real-world connectivity questions can help to identify sampling limitations associated with a particular methodology, further develop research questions and hypotheses, and investigate eco-evolutionary feedback interactions that span the connectivity continuum. We hope this framework will serve as a foundation for conducting and communicating research across subdisciplines, resulting in a more holistic understanding of connectivity in natural systems

Seawater carbonate chemistry and Nucella behavior

Local adaptation can cause predator populations to vary in traits and their effects on prey, but few studies have tested whether divergent predator populations respond differently to acute environmental stressors. We tested how Nucella dogwhelks from 3 populations with natural exposure to distinct environmental regimes in the California Current System altered consumption of mussel prey (Mytilus californianus) in ambient (pH 8.0, 429 µatm partial pressure of CO2 [pCO2]) and acidified (pH 7.6, 1032 µatm pCO2) seawater. Overall, experimental acidification increased the variation in consumption time observed among populations. We found reduced consumption time for the population that experienced more frequent exposure to low pH conditions in nature but not for populations with less prior exposure. Exposure to acidification also altered the individual components of consumption time—search time and handling time—depending on source population. These results indicate that impaired predator performance is not a universal response to acidification, that predation responses to acute acidification can be population specific, and that individual population responses may relate to prior exposure. Our study highlights how population-specific responses to climate change can lead to differences in ecological effects that may restructure prey communities at local scales

Data from: Managing hydropower dam releases for water users and imperiled fishes with contrasting thermal habitat requirements

1) The construction of dams on large rivers has negative impacts on native species. Environmental flows have been proposed as a tool to mitigate these impacts, but in order for these strategies to be effective they must account for disparate temperature and flow needs of different species. 2) We applied a multi-objective approach to identify tradeoffs in dam release discharge and temperature for imperiled warm- and cold-water fishes while simultaneously meeting the needs of human water users. 3) Using the Sacramento River (California, USA) as a case study, our model suggests that current management aimed at conserving an endangered cold-water species (winter-run Chinook salmon; Oncorhynchus tshawytscha) and providing high discharge for downstream water users has detrimental impacts on a threatened warm-water species (green sturgeon; Acipenser medirostris). 4) We developed an optimal dam release scenario that can be used to meet the needs of salmon, sturgeon, and human water users. Our results show that dam releases can be managed to successfully achieve these multiple objectives in all but the most severe drought years. Synthesis and applications This study shows that managing dam releases to meet the needs of a single species can have detrimental effects on other native species with different flow and temperature requirements. We applied a multi-objective approach to balance environmental requirements of multiple species with the needs of human water users. Our findings can be used to guide management of Shasta Dam and our approach can be applied to achieve multi-object management goals in other impounded rivers beyond California’s Sacramento River

Eco-evolutionary feedbacks in community and ecosystem ecology: interactions between the ecological theatre and the evolutionary play

Interactions between natural selection and environmental change are well recognized and sit at the core of ecology and evolutionary biology. Reciprocal interactions between ecology and evolution, eco-evolutionary feedbacks, are less well studied, even though they may be critical for understanding the evolution of biological diversity, the structure of communities and the function of ecosystems. Eco-evolutionary feedbacks require that populations alter their environment (niche construction) and that those changes in the environment feed back to influence the subsequent evolution of the population. There is strong evidence that organisms influence their environment through predation, nutrient excretion and habitat modification, and that populations evolve in response to changes in their environment at time-scales congruent with ecological change (contemporary evolution). Here, we outline how the niche construction and contemporary evolution interact to alter the direction of evolution and the structure and function of communities and ecosystems. We then present five empirical systems that highlight important characteristics of eco-evolutionary feedbacks: rotifer–algae chemostats; alewife–zooplankton interactions in lakes; guppy life-history evolution and nutrient cycling in streams; avian seed predators and plants; and tree leaf chemistry and soil processes. The alewife–zooplankton system provides the most complete evidence for eco-evolutionary feedbacks, but other systems highlight the potential for eco-evolutionary feedbacks in a wide variety of natural systems

Blueback herring haplotypes

Blueback herring haplotype calls from all combinations of locus and individual