The study, published in the journal The American Naturalist
, was part of Rogalski’s dissertation research at Yale. She is now a postdoctoral fellow at the University of Michigan’s Department of Ecology and Evolutionary Biology.
Given the widespread occurrences of toxic pollution, including heavy metals, the results illustrate the importance of better understanding the drivers and implications of such maladaptation patterns, Rogalski said.
“If this increase in sensitivity to metals over time affects the ability of Daphnia
to survive and reproduce in natural (contaminated) environments, this would mean that toxicity is increasing following long-term exposure,” Rogalski said. “When making regulatory decisions, we consider toxicity responses to be static and uniform; however, populations in different locations vary in their sensitivity to contaminants, and this study shows that sensitivity can evolve through time.
“This is something we should consider when we estimate the risk associated with the release of toxic chemicals into the environment.”