Craig Benkman – Diversification and speciation in crossbills: the importance of a “charmed life”

Professor and Robert B. Berry Distinguished Chair in Ecology
University of Wyoming

After providing an overview of the patterns and processes driving crossbill diversification, this talk will focus on the premating reproductive isolating barriers contributing to speciation in crossbills. Crossbill are interesting in this regard because many crossbill taxa have diverged recently (<11,000 years ago) and have likely diverged with gene flow. I will emphasize assortative flocking behavior, because crossbills flock year-round and choose mates from within flocks, and because high levels of assortative flocking can evolve as a barrier to gene flow without geographic isolation. Importantly, tradeoffs in feeding performance affect the benefits from assortative flocking, and thus variation in the strength of feeding tradeoffs influences the extent of assortative flocking. We find that variation in feeding tradeoffs during breeding can seemingly account for differences in premating reproductive isolation among locations for a pair of crossbill taxa, and for the overall levels of premating reproductive isolation and genomic divergence between different taxa of crossbills.

Craig Benkman is a Professor and Robert B. Berry Distinguished Chair in Ecology at the University of Wyoming. Before moving to Wyoming in 2004, Craig was on the faculty in the Department of Biology at New Mexico State University. He received a B.A. from UC Berkeley, a M.S. from Northern Arizona University, a Ph.D. from State University of New York at Albany, and conducted postdoctoral research at Princeton University and the University of British Columbia. Craig is an evolutionary ecologist and ornithologist who has published about 100 peer-reviewed papers pertaining mostly to the ecology, evolution, and conservation of birds. He is a Fellow of the American Association of the Advancement of Science, and received the E. O. Wilson Naturalist Award from the American Society of Naturalists in 2014 and the William Brewster Memorial Award from the American Ornithological Society in 2019.