Identifying how sociality evolved is a key goal in biology. With respect to feeding and nutrition, it is unclear how social animals evolved to mediate their own personal feeding behavior while also engaging in social feeding behaviors, such as the collection of food for their offspring. Bumble bees are considered social, but they have an annual life cycle wherein each spring, solitary queens must initiate new nests. Queens directly care for their first offspring as they develop in the nest and only cease performing this care when their daughters remain in the nest and assume all brood care. This project examines how queen bumble bees navigate the transition from being solitary, to expressing maternal care, to ceasing brood care, and identifies how these changes are mediated at the molecular level. A team consisting of undergraduate researchers from local community colleges and a university, a graduate student, and a postdoctoral researcher, will carry out the research. This will create a bridge between community colleges and a public university system and give valuable research experiences to traditionally underserved students. Hands-on research activities will also be integrated into two undergraduate courses taught by the PI to give students research experience in the classroom, and an outreach program based on bumble bee life history and conservation will be developed to inform the public about this threatened pollinator group.
The evolution of parental care and eusociality are both fundamental topics in social research. Lineages that exhibit both are particularly important systems for examining how social behavior evolves. This project explores the regulation and evolution of maternal care in bumble bee queens, which transition from a solitary to social lifestyle during the nest initiation stage. First, experiments that cause changes in offspring investment and brood care will be used to explore hypotheses inspired by both subsocial insects, which resemble bumble bee queens at this life stage, and also honey bees, which share a common origin of sociality with bumble bees. Next, RNAseq will be used to identify genes that change expression patterns in association with changes in offspring investment, and are thus candidates for the co-regulation of personal feeding and brood care. Evidence for the behavioral precursor hypothesis and the novel genes hypothesis will be explored by examining, respectively, whether these genes are conserved, or whether they are novel in either the bumble bees or in the lineage of progressively-provisioning bees they belong to. This project will improve our understanding of how sociality evolves using the bumble bee system, which is more socially plastic than many eusocial lineages but also exhibits greater social complexity than the subsocial insects. The project will also generate new insights into how feeding behavior is regulated in social systems, and shed light on how social animals have evolved mechanisms that mediate personal nutritional homeostasis while also dynamically responding to cues that mediate social feeding behaviors.
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.
