Collaborative Research: A legacy of parental experiences: the role of conflicting maternal and paternal cues on the evolution of transgenerational plasticity

About This Grant

An offspring’s traits, such as appearance or behavior, are shaped by both its genes and its environment. Scientists now know that parents' experiences, well before offspring exist, also influence offspring traits. This transgenerational parental impact allows parents to help offspring prepare for survival in risky or stressful environments, even if the parents and offspring never physically meet, by altering how genes are expressed (turned on or off) in their offspring. Most research has focused on how mothers pass along information or cues about their environment to their young, but in reality, both mothers’ and fathers’ experiences are important. For example, if both parents experienced similar environments, their combined cues to offspring might make transgenerational plasticity more beneficial compared to the mother’s cue alone. On the other hand, if mothers and fathers experience different environments, the information they provide their offspring might be contradictory and not beneficial. This research uses both theoretical models and laboratory experiments to ask how offspring respond to maternal and paternal information that differs and whether parents develop behaviors to avoid or manage these mismatches, including choosing mates with similar experiences or changing how they care for their young. By exploring how both parents’ experiences collectively affect their offspring, this work will help us predict when offspring respond to parental cues and when they ignore them. The project will also train undergraduate and graduate students by offering long-term internships that provide students with independent research opportunities, coding workshops to train students in mathematical modeling, and seminars to prepare students for careers in science after they graduate. Biologists are particularly interested in understanding why plasticity occurs, when it is adaptive, and how it influences biological patterns. While transgenerational plasticity (TGP) can benefit offspring beyond what is possible for within-generational plasticity alone, mismatches in parental experiences (e.g., maternal cues of low predation and paternal cues of high predation) can result in traits that are maladaptive for the offspring. We hypothesize that parents can gain and respond to environmental information from mates in ways that may rescue offspring from the detrimental effects of mismatching. We will use mathematical models to understand whether TGP is more likely to arise when maternal and paternal cues match and when differential allocation of care in response to mismatching cues is possible. We will then use experiments with threespined sticklebacks (Gasterosteus aculeatus) to evaluate whether females use mate choice to reduce the frequency of mismatching maternal and paternal cues. Finally, we will empirically test whether males differentially allocate paternal care in response to maternal experience, if this differential allocation reduces the fitness costs of mismatching maternal and paternal experiences, and if it alters the ways in which TGP persists across generations. We predict that mate choice and differential allocation in response to parental cues may allow for the evolution of TGP in environments that would otherwise not select for TGP. This could explain the ubiquity of transgenerational plasticity across taxonomic groups, despite existing theory predicting it should evolve only under limited conditions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.