Lauren Ruane and Dave publish paper on mating system variation across the range of a primarily selfing plant

Lauren Ruane and her students at Christopher Newport University conducted very detailed experiments documenting trait variation and its functional consequences across the geographic range of Clarkia xantiana ssp. parviflora, which is a primarily selfing plant. Floral and mating system variation in selfing taxa is often ignored and assumed not to have important consequences. Our results show considerable variation in the opportunity for outcrossing, the time period during which a plant has the capacity to outcross prior to the deposition of self pollen. In addition to protandry, delayed stigma receptivity differed substantially among some populations, providing a second mechanism for delaying selfing.

Ruane, L., S. Magnum, K.W. Horner, & D.A. Moeller. 2020. The opportunity for outcrossing varies across the geographic range of the primarily selfing Clarkia xantiana ssp. parviflora. American Journal of Botany 107:1198-1207. pdf


Amanda’s ragweed population genomics paper published in PLoS Genetics!

Amanda worked with the Tiffin lab, especially Tuomas Hamala, to analyze transcriptomes from across the north-south extent of the geographic range of common ragweed. They identified loci bearing footprints of local adaptation, and then use genotype-expression mapping and co-expression networks to infer the connectivity of the genes. The results indicate that the putatively adaptive loci are highly pleiotropic, as they are more likely than expected to affect the expression of other genes, and they reside in central positions within the gene networks. 

Hämälä, T., A.J. Gorton, D.A. Moeller, & P. Tiffin. 2020. Pleiotropy facilitates local adaptation to distant optima in common ragweed (Ambrosia artemisiifolia). PLoS Genetics 16:e1008707. pdf

Meta-analysis published in American Naturalist

Ryan, Amanda, and Dave worked with other UMN collaborators on a synthesis of local adaptation that compares the strength of local adaptation to abiotic versus biotic environments. It also examines the latitudinal variation in the strength of the effects of abiotic and biotic environments on fitness. It combines a quantitative meta-analysis of published datasets with a qualitative metasynthesis, which systematically examines the text of those published papers. This mixed-methods approach has not been used in ecology and evolutionary biology but has begun to emerge in other scientific literatures.

Check it out here!

John’s paper on biotic interactions and geographic range limits in press at Evolution

The second chapter of John’s dissertation uses a reciprocal transplant experiment combined with the manipulation of biotic interactions (herbivory and pollination) to examine the extent to which biotic interactions determine fitness inside and beyond the geographic range of Clarkia xantiana. This paper follows up on his previous paper on this topic, which was published in the American Naturalist this year.

Amanda’s paper on adaptation to climate change in press at Oecologia

Amanda Gorton conducted a common garden study in Minnesota of 26 populations of common ragweed spanning a latitudinal range from Minnesota to Louisiana. She was particularly interested in how populations responded to future patterns of rainfall predicted under climate change. She simulated both an increase and decrease in rainfall across her experimental site using rainout shelters (and redistribution of rainfall). Her results have implications for range shifts of populations with climate change. Check out her paper in “early view” at Oecologia!

Amanda and John BOTH receive the prestigious Philip C. Hamm Memorial Scholarship!

Each year, the U. of Minnesota awards the Hamm Memorial Scholarship to one graduate student in the latter phases of their PhD. This is the most prestigious award in the plant sciences at UMN.

This year the committee could not decide between Amanda and John and so awarded the scholarship to both! Incredibly proud of how well rounded each of their accomplishments has been in research, teaching, and outreach/service!