Non-genetic inheritance encompasses the many ways in which changes in parental environment affect the next generations (so-called parental effects), as well as the parent-to offspring transmission of epigenetic marks. While paternal effects have sparked an interest in medical research over the past decade, the field is still in its infancy in evolutionary ecology research. Yet, paternal non-genetic inheritance can have strong evolutionary applications, particularly regarding a species’ capacity to respond to environmental changes. Heavy metal pollution is among the major environmental pressures currently affecting not only terrestrial biodiversity but also human health. As such, heavy metal pollution presents an increasingly important concern worldwide.
PEARL’s central hypothesis postulates that metal pollution, even at low doses, can alter the sperm quality of male birds, as example at the epigenetic level (DNA methylation), which would then result in observable phenotypic alterations in the offspring. The objectives of this project were trifold: 1) to quantify the effects of heavy metal pollution exposure on physiology and behavior, 2) to quantify the effects of heavy metal pollution on sperm morphology, 3) to determine whether paternal effects of pollution are detectable in offspring of contaminated fathers.
To do so, we combined an experimental approach with a captive Japanese quail population, and experiments in a wild population of songbirds breeding along a metal pollution gradient in Harjavalta, Southwestern Finland. Our primary finding is that ecologically realistic concentrations of a ubiquitous and persistent metal, lead, can induce effects on the offspring of exposed males, with important consequences for their survival. Our now work calls for future research evaluating the extent to which paternal effects contribute to global parental effects and how this can affect the offspring’s ability to respond not only to contaminants but also other anthropogenic pressures.
