CAREER: Integrative Systematics: Taxonomy and Evolution of Megalomyrmex Ants and Their Venom

Ohio State University, The, Columbus OH

Investigators

Abstract

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The proposed work investigates the changes and function of ant venom and species diversification over time. Megalomyrmex consists of 45 ant species with a range of lifestyles, where some are predators and others maintain more beneficial associations with other insects. These mutualist ant species protect their associates from predatory threat using venom weaponry. In contrast, several Megalomyrmex species are social parasites (i.e., one social insect exploiting another social insect) and use their venom to dominate these other species. In this case, Megalomyrmex ants consume young ants and food from their partnering species. Megalomyrmex is exceptional among venomous organisms because of the breadth of interactions mediated by venom. By studying the composition of venom, novel natural products, some of which can be used in agricultural or medicinal practices, could be discovered. This research brings together public engagement and a research-integrated education plan that includes the development of a non-biology majors’ undergraduate course—blending research and outreach foci, while creating broad access to scientific thinking. These projects will involve training and mentoring of postdocs, PhD students, and undergraduate student researchers. Trainees will develop projects aligned with proposed aims and present results at scientific meetings and in scientific publications. An undergraduate summer internship program associated with Ohio Ant workshops will be established. The evolution of venomous species and venom complexity can provide wide-ranging insights into evolutionary ecology because changes in venom composition catalyze both speciation and coevolution. The proposed research leverages current venom evolution theory to explore comparative questions relating to ant venom alkaloids. The challenge is that, despite multiple parallel origins, we are in the early stages of understanding how eco-evolutionary processes relate to venom and lineage diversification. This is in-part because of the necessity for cross-cutting approaches using comparative phylogenetics, functional assays, and behavioral and chemical ecology. Megalomyrmex is an ideal model to address questions about ant lineage diversification and how venom evolves because species engage in various trophic interactions with other organisms. In this project, researchers will: (1) determine venom and lifestyle (i.e., predator, trophic mutualist, parasite) evolution in Megalomyrmex ants using comparative phylogenetics, while uncovering ecological relationships between host and parasite ant species pairs using cophylogenetic inference; (2) clarify how ecological lifestyles predict venom-related traits (e.g., use, venom drop size, toxicity) and contribute to venom evolution, by testing venom complexity hypotheses; (3) delimit cryptic species and revise Megalomyrmex while training taxonomists using a modern integrative taxonomic approach; and (4) broaden engagement in science and nature by demonstrating the ecological relationships of symbioses, while instructing a new general education course, Symbiotic systems: Serendipity or selfishness. This course-based undergraduate research experience (CURE) will include comparative phylogenetics, integrative taxonomy, and natural history studies. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.