Scientists' Warning on the Rapid Evolution of Parasites in the Anthropocene

Human activities are changing the natural world at an accelerating pace, and as a consequence exerting novel and often strong selection pressures on living organisms. For species with traits conferring huge inherent evolutionary potential, like parasites, the outcome may be rapid adaptive responses spanning multiple phenotypic traits. The rise of drug resistance in parasites of domesticated animals is well documented; however, rapid changes in other key parasite traits may go unnoticed. In this contribution to the Scientists' Warning series, we argue that parasites are capable of evolving quickly to meet the new pressures of the Anthropocene. After summarizing evidence demonstrating their ability to evolve quickly and the magnitude of the anthropogenic selection pressures they now face, we discuss the basic types of adaptive responses we might expect. Next, we propose methods to track rapid parasite evolution in real time, as well as possible approaches to either slow it down or mitigate its impact on animal production systems. Our aim is to raise awareness of this concerning but underappreciated phenomenon and appeal for greater research into rapid parasite evolution in the Anthropocene and its consequences.