The role that environmentally-induced phenotypic plasticity plays in adaptive evolution has been debated for decades. Does plasticity shield genotypes from selection following a novel shift in the environment and, in turn, impede adaptation? Or does phenotypic plasticity accelerate the rate at which populations attain new fitness peaks and thereby facilitate adaptation? This project is testing the influence of plasticity on resultant evolutionary processes by resurrecting historic propagules of zooplankton following a change in natural selection. Multiple lakes in Wisconsin were recently invaded by a novel invertebrate predator (spiny waterflea). Comparisons across contemporary populations show that invasion by spiny waterfleas is associated with rapid evolution of Daphnia prey. Here we are pairing ‘resurrection experiments’ with experimental evolution in the lab to ultimately determine if plasticity promotes or impedes adaptation. This work is funded by a current NSF CAREER grant (2017-2022).

Vertebrates exhibit extensive variation in brain size. It has long been assumed that this variation is the product of natural selection. Yet, despite more than 100 years of research, the ecological conditions that select for changes in brain size are unclear. Trinidadian killifish (Rivulus hartii) are located in sites that differ in predation intensity. We recently showed that a decline in the rate of predation is associated with the evolution of a larger brain. These results provide a clear correlation between an ecological selective pressure and shifts in brain size, but they tell us nothing about how and why these differences in brain size have evolved. We are therefore now experimentally testing the links between the evolution of brain size, cognition, and behavior.

Between 1951 and 1962, the U.S. Department of Energy detonated one hundred nuclear weapons during above-ground testing at the Nevada Test Site (NTS), near Las Vegas. The resulting fallout deposited radioactivity across much of Arizona, Nevada, and Utah. In the short term, radiation exposure raises rates of genetic change (i.e., mutation) and negatively affects survival and reproduction for most organisms tested. In the long term, however, the evolutionary impacts of radiation exposure are not yet clear. In colaboration with Dr. Yoel Stuart (Loyola University Chicago), we are evaluating the evolutionary consequences of nuclear testing in the Southwestern US by resurrecting populations of waterfleas from lakes in Utah. The goal is to hatch Daphnia from time periods prior to the onset of nuclear testing and then track shifts in phenotype following the onset of nuclear activity. This project is currently funded by an NSF EAGER grant (DEB 2028775).

We are part of an international team (Andrew Hendry, McGill Univ; Dan Bolnick, UConn; Katie Peichel, Bern; Rowan Barrett, McGill Univ; Alison Derry, Univ Quebec) that is quantifying feedbacks ecology and evolution following the experimental restoration of several lakes in Alaska. The Alaska Department of Fish and Game recently treated 10 lakes with rotenone to remove invasive pike. To begin to restore the native fish communities, we introduced sticklebacks into these lakes in June 2019. Importantly, we added contrasting morphs of sticklebacks (i.e., benthic vs. limnetic) to each lake and concurrently assessed a suite of community and ecosystem variables as a starting. Our goal is to now assess the interplay between stickleback adaptation, Daphnia evolution, and the ecology of these lakes over time.