The generational impact of illness

by Morgan Sherburne, University of Michigan
September 8, 2025

When University of Michigan researchers were looking at the effects of a parasite on a tiny freshwater crustacean, they found something unexpected.

The organism infected with the parasite fared well despite their illness, but many of their offspring, who were not infected, died young. The finding sheds light on how illness may affect not just the organisms who originally contract the infection, but their children as well.

“Scientists have spent a lot of time studying virulence, which is generally defined as the impact a parasite has on the fitness of its host. But all of that usually only considers the impact on the particular host individual who is infected,” said Meghan Duffy, U-M professor of ecology and evolutionary biology and senior author of the study, which was supported by the U.S. National Science Foundation and the Gordon & Betty Moore Foundation.

“We know for other things, like if a mother is starving and doesn’t have enough resources, that can influence her offspring. If she’s exposed to a predator, that can influence her offspring. We know these effects can carry across generations. We just somehow haven’t really considered that for virulence, as far as we can tell.”

Keep reading: https://news.umich.edu/the-generational-impact-of-illness/

Read the Ecology paper: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.70165