I am broadly interested in social insect behavior and the mechanisms underlying social evolution among insects. One of the hallmarks of social insect species is a division of labor among colony members, which represents an important step in the transition between solitary and social living. Division of labor also plays a key role in the tremendous success of social insects, allowing for increased efficiency of colonies with respect to nest building, food collection, and reproduction.
My goal is to use a comparative genomics approach to understand the mechanisms by which division of labor has evolved in bees.
Eusociality, which involves a reproductive division of labor, overlapping generations and cooperative brood care, represents a highly successful strategy found in just a few lineages, primarily among insects. Although rare in the tree of life, eusociality has evolved many times within the order Hymenoptera, allowing for unique opportunities to test evolutionary questions within a monophyletic group. We have made great progress in describing the molecular basis of castes in eusocial insect species, but it is unknown whether these molecular mechanisms were important in the origins of eusociality. Additionally, it is unclear whether the same pathways were involved in each independent origin of eusociality, or if convergent phenotypes arose via lineage-specific mechanisms. Growing evidence points to the conserved role of particular gene networks in the transition to social behavior. This “genetic toolkit” model involves highly conserved genes that were co-opted for social functions during the multiple origins of eusociality.
A rigorous test of the genetic toolkit model of social evolution requires a comparative approach, including species in multiple lineages that span a range of sociality. Bees are an ideal system in which to perform this comparison, as extant bee species meet both of these taxonomic and behavioral criteria.
Megalopta genalis, a neotropical sweat bee (Halictidae), is facultatively eusocial and displays a wide range of social behaviors within a single population, including both solitary and eusocial nests. Phylogenetic studies of bees point to a solitary ancestral lifestyle, suggesting that mechanisms underpinning social behavior in M. genalis may represent those important in the evolutionary transition from solitary to social reproduction in this lineage.
1) Building genomic tools for Megalopta genalis to investigate the molecular bases of reproductive division of labor in this facultatively eusocial species.
2) Identifying behavioral and molecular correlates of reproduction in worker bumble bees that have transitioned from worker tasks to reproduction.
Inside Artificial Nest