Collaborative Research: LIFE: Leveraging agricultural weeds to understand evolutionary convergence.

About This Grant

Modern agriculture is essential for feeding the world's growing population, but weedy plants that invade crop fields cause billions of dollars in losses annually and threaten food security. While most non-crop plants struggle to survive in agricultural environments, some species have rapidly evolved to thrive in these human-managed landscapes, becoming persistent problems for farmers. This research investigates how these weedy plants evolved so successfully, using a plant genus called Amaranthus that includes some of the most troublesome agricultural weeds in North America. Understanding the biological mechanisms that allow certain plants to quickly adapt to new environments like agricultural systems is crucial for developing more effective, sustainable weed management strategies and for predicting which species might become future problems. This knowledge will help farmers and agricultural scientists stay ahead of evolving challenges while also advancing our broader understanding of how organisms adapt to rapidly changing conditions. The project will advance education by training students spanning urban and rural communities, through a new plant evolution curriculum, creating international genomics workshops, and engaging local communities through citizen science projects that help track weed distributions while building scientific literacy. This research will generate high-quality genome-wide data for nearly all species in the genus Amaranthus, which contains 11 globally important agricultural weeds alongside non-weedy relatives, providing an unprecedented dataset for studying convergent evolution in response to agriculture. The project combines phylogenomic analyses across the genus with detailed population genomic studies of three focal weed species (A. palmeri, A. retroflexus, and A. albus) collected from agricultural and natural habitats. Common garden experiments will test hypotheses about key traits that facilitate weediness, including germination under stress conditions, competitive ability, and phenotypic plasticity. Advanced comparative genomic methods will identify regions of accelerated evolution in weedy lineages and distinguish between different sources of adaptive genetic variation, including ancestral polymorphisms, introgression between species, and parallel mutations. The researchers will integrate genomic and phenotypic data through phylogenetic genome-wide association studies to map the connections between genotype, phenotype, and environmental selection pressures. This multi-scale approach will reveal the genetic architecture underlying convergent adaptation to agricultural environments and provide insights into the repeatability of evolutionary responses to human-mediated environmental change. 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.