The National Science Foundation awarded Dr. Mark Fishbein, associate professor of Plant Biology, Ecology, and Evolution at Oklahoma State University and director of the University Herbarium, a three-year grant totaling $642,000 to study the evolution of milkweed, a species crucial to the rapidly declining monarch butterfly population, using genome sequences. In previous research, Fishbein has investigated the evolution of milkweed defenses in response to monarch feeding.  However, the evolutionary relationships among milkweed species are still not well understood.

Reconstructing the past evolution of plant species is problematic because rapid diversification of new plant species often leaves conflicting signals in the DNA sequences that make up plant genomes. Milkweeds are no exception. Fishbein’s newly funded project will use an unprecedentedly large number of genes and novel analytical approaches to untangle the conflicting evolutionary signals present across the genome.

The results of this study will answer questions about where milkweeds originated and how they became distributed from Canada to South America. They will also have implications for better understanding the coevolution between milkweeds and monarch butterflies and the evolution of plant defense, as well as provide a robust evolutionary context for understanding the results of other scientific studies of pollination, reproduction and genome evolution of milkweeds. More generally, this research will demonstrate the feasibility of solving difficult phylogenetic problems at the species level in plants by employing improvements in next-generation sequencing techniques. The work combines methods for targeted sequencing of hundreds of specific regions of the nuclear genome applied to unusually large samples of each species.

Funded by the NSF’s Phylogenetic Systematics Program, the project is a collaborative effort with Dr. Shannon Straub at William and Hobart Smith Colleges in New York.  The project will train postdoctoral, graduate student, and undergraduate student researchers in cutting edge bioinformatics and genomic methods, including approaches to understanding plant diversity. The project will also support the development of new K-12 educational programs in New York and educational materials about monarch and milkweed coevolution at The Botanic Garden at Oklahoma State University.