Coupling of Barriers to Gene Exchange: The Role of Demographic, Genetic, and Adaptive Mechanisms in the European Corn Borer Moth

Accounting for the diversity of life on Earth requires an understanding of the speciation process. New species are thought to arise as populations diverge and accumulate multiple barriers to interbreeding, such as a change of mate choice, a shifted mating time, and reduced survival of hybrid offspring. A critical question concerns the specific processes and mechanisms underlying the tendency of distinct barriers to build up between populations and operate together during speciation.

This project explores three alternative mechanisms, and by focusing on a familiar agricultural pest of sweet corn, agricultural sustainability grows out of the project’s research activities. By recruiting and training a variety of undergraduates to participate in these activities, the project will enhance students’ research skills and open pathways to science and STEM careers.

The project’s central objective is to systematically analyze the role of selection, population processes, and genetic architecture for the build up of distinct barriers to gene exchange in the European corn borer moth system. First, the researchers will conduct genome resequencing from across the distribution range to explore the history of species spread and the potential for co-occurrence of distinct barriers through range expansion and population mixing.

Second, through population cage experiments and fitness assessments, the project will determine if prezygotic isolation traits also contribute to postzygotic isolation. Third, genomic comparisons of population pairs differing by independent or coincident barriers will be used to detect evidence that associations between barriers are favored by selection.

Finally, the researchers will use CRISPR/Cas9 technology to investigate pleiotropic reproductive isolation. This research aims to contribute not only to an understanding of speciation but also to practical applications in agricultural sustainability, environmental health, and educational outreach. Collaborative sampling with growers supports economic profitability and promotes resilient local food systems.

Passive monitoring offers early warnings of moth infestations, aligning with integrated pest management principles to manage pests while prioritizing overall ecosystem health. Lastly, outreach initiatives, including a secondary curriculum for a national agriculture education program, aim to spark curiosity about environmental biology and advance evolution literacy.

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.