Offspring overcome poor parenting by being better parents

Abstract

AbstractThe evolutionary repercussions of parental effects are often discussed as fixed effects on offspring phenotype that can even have negative influences on offspring fitness if parental and offspring environments do not match. Yet individuals are not passive recipients and may mitigate the persistence of parental effects through their own behavior. Here we test how the burying beetleNicrophorus orbicollis, a species with highly developed parental care, responds to poor parenting. We manipulated the duration of parental care received and measured both offspring and grandoffspring traits of males and females. As expected, reducing parental care negatively impacted key traits that influence fitness, including offspring development time and body size. However, offspring that received reduced care increased uniparental care when they became parents and, in addition, shifted the type of parenting behavior to more direct feeding of offspring. Parents that had received full care as larvae invested more time maintaining the food resource, a form of indirect parental care. As a result, both the number and mass of offspring were unaffected by the different developmental experience of their parent. Our results show that flexible parental care can overcome poor parental environments and limit negative parental effects to a single generation.ImpactSummaryParental care is one of the most visible means by which parents influence the development of their offspring and is expected to evolve to buffer offspring from challenging environments. Yet, variation in parental care itself can have negative effects on offspring that cascades across generations. How can offspring overcome these poor developmental environments? Here we test the hypothesis that organisms can compensate for their own poor developmental environments by changing their parental care behavior in the burying beetleNicrophorus orbicollis. Specifically, we asked whether receiving poor parenting begets poor parenting. We manipulated the amount of parental care provided by burying beetles, an insect that feeds its offspring regurgitated food. Reduced parental care resulted in smaller offspring that developed more slowly in early developmental stages. However, when these offspring reached adulthood, they modified their own parental care so that the grandoffspring were unaffected by the negative conditions experienced by the previous generation. We suggest that these result show that parental care not only serves as a buffer within-generation but can also compensate for poor natal environments across generations.