Research in our lab centers on understanding ecological and evolutionary mechanisms related to species and community response to environmental change with the goal of informing practices that will mitigate the loss of biodiversity and ecosystem health. Our current predictive modeling toolkit calibrated with modern data is not enough to adequately address these questions, because we know that modern anthropogenic pressures have already influenced ecological and evolutionary processes, and we expect future combinations of environmental variables to be non-analogous to what we find in the modern world.
Biodiversity conservation on a dynamically changing planet
We approach this challenge by integrating information about traits and their modern and past environments, along with their evolutionary histories, into predictive models of future change. Natural history collections are crucial to this work, as they preserve specimen-based trait information still to be gathered. We develop and apply new quantitative approaches to integrate paleo and modern trait data, which translates into new and newly adapted methodology to bridge the fields of biogeography, conservation, and paleontology.
Figure 1. Species will shift their ranges in response to rapidly changing climates. Landscape features act as filters or barriers necessitating alternate paths. Figure from McGuire et al. 2023. PNAS.
Our approach aims to build and strengthen conceptual frameworks to be able to answer questions about the response of species to environmental change and it improves the integration of modern and paleontological data. For example, we’ve recently contributed to organizing and editing a symposium followed by a special feature in Proceedings of the National Academy of Sciences USA, on “The past as a lens for biodiversity conservation on a dynamically changing planet.” The special feature builds synthesis in conservation science by integrating across spatial and temporal scales to refine our perspective on conserving today’s fast-vanishing biodiversity. It explores how species and communities function dynamically to respond to large-scale, rapid environmental change (Figure 1), highlighting proposed solutions for conserving biodiversity on a rapidly changing planet. The goal was to capture conversations and approaches that transcend fields.
Ecometrics: traits bind the past and present to inform conservation
Ecometrics is a powerful tool for identifying relationships between functional traits and environmental conditions that have been crucial for maintaining ecosystems through time (Barnosky et al. 2017 Science). Rather than assessing the fit between an individual species and its environment, the method evaluates the relationship between functional traits of an entire community and environments in which they occur (Figure 2). It has been demonstrated to be incredibly powerful for assessing ecosystems through time and into the future because it is scalable across time and through space (McGuire et al. 2023 PNAS; Short etal. 2023 PNAS).
Figure 2. A) Ecometric relationships describe the distribution that results when functional gamma diversity is filtered by environmental conditions. The local community represents functional alpha diversity. B) Ecometric relationships result from sets of traits being better suited to local environmental conditions.
Phylogenetic comparative methods and the geographic distribution of species
There is a wealth of phylogenetic theory that provides a general framework for modeling trait evolution under different possible evolutionary scenarios. We are beginning to understand how to use information from physiological tolerances and modern geographic distributions of species to infer possible geographic histories. We developed an approach to integrate phylogenetic comparative methods, species distribution modeling, paleontological data, and general circulation models of past climate (Figure 3, Lawing et al. 2016 American Naturalist, and Lawing 2021 Paleobiology) to better understand the history of geographic responses to climate change and to determine how much we can infer from integrating these methods and data.
Figure 3. Paleophylogeographic Species Distribution Models. Composite oxygen isotope curve for the last 320 ky inset with paleophylogeographic models of timber (green), prairie (red), and mojave (blue) rattlesnakes’ projected suitable habitat. Phylogenetically scaled climate envelopes were projected onto isotopically scaled paleoclimate models to generate these maps. (Lawing and Polly 2011).