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28 POTATO GROWER | MARCH 2021 4086-6CraryIndustries12h.indd 1 4086-6CraryIndustries12h.indd 1 1/22/21 10:41 AM 1/22/21 10:41 AM REVOLUTION IN EVOLUTION Epigenetics is an increasingly hot field. Basically, it's the study of how environmental stresses—from starvation to air pollution to pesticides—can add or remove chemical tags to an organism's DNA, flipping a genetic switch that changes its health and behavior. DNA methylation was first shown to occur in human cancer in 1983. In the early 2000s the epigenetics revolution in biology began to reveal how environmental change can turn certain genes on or off, leading to profound changes in an organism without changing its DNA. And it's well-known that many insects in agricultural areas develop pesticide resistance; it's not just Colorado potato beetles. More than 600 species have developed resistance to over 300 pesticides, with tens of thousands of reports from around the world. A growing body of research shows that many of these involve epigenetic mechanisms. In their experiment, the UVM scientists, with a colleague from the University of Wisconsin, gathered adult beetles from organic farms in Vermont. They divided up the offspring, treating them with different doses of imidacloprid—some high, some low, some to a less toxic chemical similar to imidacloprid—and some to just water. After two generations, beetles whose grandparents had been treated to any level of pesticide showed decreased overall methylation—while the ones exposed to water did not. Many of the sites where the scientists found changes in methylation are in genes associated with pesticide resistance. The parallel response across all the pesticide treatments suggests that "mere exposure to insecticides can have lasting effects on the epigenetics of beetles," says Chen. It's one thing to suggest that stress changes a particular organism, quite another to suggest that physical characteristics it acquires by stress or behavior can get passed down for numerous generations. A blacksmith who grows strong from a lifetime of