A valley in the Spanish Pyrenees near Planoles, where there is a narrow hybrid zone of two snapdragon subspecies. Photo by Carina Baskett.
Status
Research is not currently an active part of my job, but I am still publishing old projects, and I still love to think and talk about plant evolutionary ecology, especially plant-insect interactions, especially herbivore-driven plant speciation. So if you're here because you want to talk about something I wrote in a journal or on the internet, don't hesitate to reach out! Also, I would LOVE to pass along the knowledge/seeds/specimens/data I amassed on plant-insect interactions in Phytolacca to someone interested in pursuing research in that system. There's an exciting pattern that Florida populations (which some people have called a different subspecies or species) have distinct chemistry and palatability compared to populations further north. It could be a good system for studying local adaptation or speciation driven by plant defense evolution!
Summary
My research is grounded in natural history and combines ecology and evolution to ask how plants interact with and adapt to their environment. I am especially excited about how plant-insect interactions like pollination and herbivory shape plant trait evolution. I use a range of approaches in my research, from field observational studies at the continent scale, to common-garden plant metabolomics and lab experiments with caterpillars.
Before coming to Georgia Tech, I was an ISTplus postdoctoral fellow in Nick Barton's group at IST Austria, a research institute outside Vienna. I studied natural selection on flower color in a hybrid zone of two subspecies of wild snapdragons. For my PhD research, I worked on latitudinal patterns in plant-insect interactions (herbivory and pollination). I completed my PhD in 2018, co-advised by Doug Schemske and Marjorie Weber at Michigan State University. I was in the Plant Biology Department and the Ecology, Evolutionary Biology, and Behavior Program.
Publications (email me for pdfs)
Google Scholar profile
Baskett, C.A., L. Schroeder, M.G. Weber, and D.W. Schemske (2020) Multiple metrics of latitudinal patterns in insect pollination and herbivory for a tropical-temperate congener pair. Ecological Monographs. 90(1):e01397. DOI: https://doi.org/10.1002/ecm.1397 (open access)
Baskett, C.A., and D. W. Schemske (2018) Latitudinal patterns of herbivore pressure in a temperate herb support the biotic interactions hypothesis. Ecology Letters. 21(4): 578-587. DOI: https://doi.org/10.1111/ele.12925
Ansetett, D.N., K.A. Nunes, C.A. Baskett, and P.M. Kotanen (2016) Sources of controversy surrounding latitudinal patterns in herbivory and defense. Trends in Ecology and Evolution. 31: 789-802. DOI: https://doi.org/10.1016/j.tree.2016.07.011
Invited chapter: Baskett, C.A., and D.W. Schemske. (2015) Evolution and Genetics of Mutualism. Mutualism. J. L. Bronstein, Oxford University Press. DOI: https://doi.org/10.1093/acprof:oso/9780199675654.003.0005
Baskett, C.A., S.M. Emery, and J.A. Rudgers. (2011) Pollinator visits restored to threatened species after removal of invasive plant. International Journal of Plant Sciences. 172: 411-422. DOI: https://doi.org/10.1086/658182
Postdoc and PhD research directions
Natural selection on flower color
Flowers mediate plant-pollinator interactions by attracting and rewarding animals. But flowers also interact with nectar robbers, seed predators, and the abiotic environment; these may all be drivers of natural selection on floral traits. Nick Barton, David Field, and colleagues have been building a pedigree for over a decade in a narrow hybrid zone of wild snapdragon subspecies in the Spanish Pyrenees mountains (Antirrhinum majus subsp. pseudomajus and A. m. striatum). The subspecies diverge in flower color, a trait known to be under strong selection and to be mostly controlled by two genomic regions. For my postdoc in the Barton group at IST Austria, I worked on flower color ecology in Antirrhinum as the first step toward identifying plausible selective agents. I asked whether the probability of visits from mutualistic or antagonistic insects was mediated by flower color in the hybrid zone (short answer: no). And I experimentally tested whether flower color mediates drought tolerance (short answer: maybe). I plan to publish these results in 2022.
A crab spider enjoying a bumblebee meal on Antirrhinum majus subsp. pseudomajus. Photo by Carina Baskett.
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Flower color variation in Antirrhinum majus. From the Biodiversity Heritage Library.
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Latitudinal variation in biotic interactions
Over half of global species diversity resides in only 7% of its land area: the tropics. The question of why there is so much biodiversity in the tropics is an enduring mystery in biology. The “biotic interactions hypothesis” states that biotic interactions are more important drivers of adaptation at lower latitudes than the abiotic environment. Because biotic interactions can coevolve, this could contribute to faster diversification in the tropics. This hypothesis clearly connects environmental differences to diversification rates. There is evidence from phylogenies, the fossil record, and patterns of endemism that diversification rates are indeed higher in the tropics. Several biotic interactions, particularly mutualisms, have been shown to be more prevalent or stronger in the tropics. However, the hypothesis is still controversial, particularly with regards to herbivory.
My dissertation research, co-advised by Doug Schemske and Marjorie Weber at Michigan State University, tested the biotic interactions hypothesis in a wide-ranging herb in the eastern US, pokeweed (Phytolacca americana) and its tropical congener, P. rivinoides. I found evidence for stronger herbivore pressure and better defense in lower-latitude populations along a gradient within the US (Baskett and Schemske 2018). Patterns were especially pronounced for young leaves, which are rarely examined in comparable studies. I also compared herbivory and pollination between three regions: temperate P. americana, subtropical P. americana, and tropical P. rivinoides in Costa Rica (Baskett et al. 2020). There is strong evidence for greater importance of herbivory and pollination for P. rivinoides compared to temperate P. americana; however, the subtropical P. americana was rarely simply intermediate between the two extremes. Finally, I found that leaf chemistry, which is not commonly measured in latitudinal comparisons of plant defense, was key to explaining latitudinal variation in defense (see dissertation ch. 3; in prep to publish in 2022). In sum, I addressed some common challenges for studying latitudinal patterns in biotic interactions, and found strong evidence supporting the biotic interactions hypothesis.
Video of dissertation seminar
Over half of global species diversity resides in only 7% of its land area: the tropics. The question of why there is so much biodiversity in the tropics is an enduring mystery in biology. The “biotic interactions hypothesis” states that biotic interactions are more important drivers of adaptation at lower latitudes than the abiotic environment. Because biotic interactions can coevolve, this could contribute to faster diversification in the tropics. This hypothesis clearly connects environmental differences to diversification rates. There is evidence from phylogenies, the fossil record, and patterns of endemism that diversification rates are indeed higher in the tropics. Several biotic interactions, particularly mutualisms, have been shown to be more prevalent or stronger in the tropics. However, the hypothesis is still controversial, particularly with regards to herbivory.
My dissertation research, co-advised by Doug Schemske and Marjorie Weber at Michigan State University, tested the biotic interactions hypothesis in a wide-ranging herb in the eastern US, pokeweed (Phytolacca americana) and its tropical congener, P. rivinoides. I found evidence for stronger herbivore pressure and better defense in lower-latitude populations along a gradient within the US (Baskett and Schemske 2018). Patterns were especially pronounced for young leaves, which are rarely examined in comparable studies. I also compared herbivory and pollination between three regions: temperate P. americana, subtropical P. americana, and tropical P. rivinoides in Costa Rica (Baskett et al. 2020). There is strong evidence for greater importance of herbivory and pollination for P. rivinoides compared to temperate P. americana; however, the subtropical P. americana was rarely simply intermediate between the two extremes. Finally, I found that leaf chemistry, which is not commonly measured in latitudinal comparisons of plant defense, was key to explaining latitudinal variation in defense (see dissertation ch. 3; in prep to publish in 2022). In sum, I addressed some common challenges for studying latitudinal patterns in biotic interactions, and found strong evidence supporting the biotic interactions hypothesis.
Video of dissertation seminar
PhD research interests in 90 seconds |
Why I love basic research in 40 seconds
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