Mathematical models that capture the influence of competition, predation, disease, and other fundamental biological processes are core components of ecological research and are often covered extensively in undergraduate ecology courses. However, it can be challenging for instructors to develop in-class active learning exercises that encourage students to interact with theoretical models and simulate population dynamics, even for models that are conceptually straightforward. This is in part because students in the life sciences vary widely in their degree of experience and comfort with quantitative topics and scientific programming, making it difficult to design exercises that emphasize students’ understanding of the ecological principles at play rather than coding/mathematical implementation of the model. Here we explore the utility of the “shiny” framework for the R programming language to build web-applications that allow users to interactively change parameters and visualize model dynamics. The goal of such apps is to help instructors of large undergraduate classes to design active learning exercises that encourage students to derive biological insights from theoretical models in ecology.
Results/Conclusions
We present an R package of web-applications focused on a variety of fundamental population dynamics models. The package includes applications to interact with models of single populations (e.g. exponential growth in discrete or continuous time, logistic growth), interspecific competition, predator-prey dynamics (with either exponential or logistic growth of the prey), and other models that are frequently taught in undergraduate ecology courses. The web-apps include text explaining the model’s simplifying assumptions and each of the model’s parameters. The apps allow users to set parameter values (e.g. using slider bars or radio buttons), and generate relevant graphs based on these values. The graphs depend on the nature of the model being presented (e.g. zero net growth isoclines for models of resource competition, or population trajectories and graphs of the age distribution for age-structured models of growth in discrete time). Our web-apps are freely available online and can be directly used for smaller classrooms, and we also provide instructions for instructors to deploy their own instances of the apps. To help build this as a community resource for ecology instructors, we make the source-code for all apps freely available online, and encourage users to suggest modifications or contribute new apps.