Understanding the evolution of animal social behavior is a key topic in biology. Recently, new gateways for understanding social evolution have opened up due to advances in genomics, allowing unprecedented opportunities to study social behavior on a molecular level. By identifying which genes vary in their expression according to social roles, and how those genes have evolved across a range of social behavior, this project will shed light on the relative importance of particular genes in driving social evolution. Thus, it provides what previous studies lack. Specifically, it can clarify what types of genomic changes are important at each stage of social evolution. This step-wise approach to understanding social evolution provides major advantages over previous work, capitalizing on a unique group of carpenter bees where sociality varies from solitary to simple to complex social species. This study will incorporate students in research positions and integrate data sets into new courses. It will involve outreach activities for long-term pollinator biodiversity monitoring, including field surveys of native bees and citizen-science initiatives. A web-based interface is currently being developed to educate the public on native bees. This website will provide an interactive education tool on native pollinators to highlight their importance for agricultural, garden, and park sustainability.
For the first time, genomic tools can be used to test alternative hypotheses about the genomic basis of behavior, utilizing bee species with both simple and complex social behavior. This will be the first study to determine the types of genomic changes associated with the earliest origins of simple sociality and its subsequent elaboration into complex sociality. It utilizes a unique clade of carpenter bees where social behavior ranges enormously, from solitary to complex with many intermediate and very weakly social species. Transcriptomic assays and genome sequence comparisons will be assessed within a phylogenetic context to determine whether transitions from simple forms of cooperation to more complex societies are associated with differential expression of key genes, changes in the structure of those genes, or both. The project involves the following three key components: 1) Development of bee genome databases, where the genomes of six species will be assembled and annotated in order to provide basic information on the gene complement and functional categories of taxonomically restricted genes and to understand gene family expansion/contraction in each species. 2) Comparisons of gene expression, which will use transcriptomic comparisons across species to understand which elements of solitary behavior (foraging, reproduction) are associated with the origin and maintenance of sociality. 3) Adaptive evolution in genes and regulatory elements across the genome, which will involve sequence comparisons of genes and cis-regulatory elements across focal species to determine whether social transitions have involved adaptive changes in DNA sequences in addition to differential gene expression. The proposed project moves beyond all previous genomic studies of ants, honey bees, and social wasps by being able to capture the genetic events associated with changes at the dawn of sociality. Data will be deposited on the NCBI whole genome shotgun (WGS), functional genomic (GEO) and short read archive (SRA), and information will be provided in accordance with NCBI standards. All data will be released to NCBI upon submission for publication.
