Meeting Abstract
The evolution of family life is shaped by complex interactions between parents and offspring. Interactions may appear harmonious, but parent and offspring interests can differ. This conflict may generate co-evolution between the traits parent and offspring use to navigate and exploit parental investment. Our research examines how interactions between sexes and life-stages impact parent and embryo evolution in Neotropical glassfrogs. Parental care was considered rare and male-biased in this family. In field observations of 38 species, we found care is ubiquitous and sex-roles vary. Comparative analyses suggest male-only care evolved repeatedly from female-only care, in association with increased care durations. Parent-removal experiments in 8 species reveal that care functions to protect embryos from dehydration and predation. Removal experiments in 6 species reveal embryos hatch early to escape abandoned eggs and extend development in ovo under prolonged care. Comparative analyses indicate evolutionary changes in the magnitude of hatching plasticity are associated with changes in care duration across species. We manipulated male mating-rates in two lineages with independent origins of male care to test how social dynamics affect paternal and embryo behavior. Males that mated more cared for eggs longer, and embryos delayed hatching. Prolonged embryonic development resulted in more developed hatchlings which were better at escaping from larval predators. However, extending care periods cost fathers, extending non-breeding periods and lowering mating success. This reveals father–embryo conflict over optimum care periods. Hatching plasticity allows these embryos to exploit changes in paternal investment influenced by female mating patterns. More broadly, embryo strategies are evolving in association with parental care across species.
