Sandra Rehan

About Me

The Rehan lab research focus is social evolution and biodiversity. We have a special interest in the behaviour, ecology, and evolution of bees. The lab has four main foci: molecular phylogeny, comparative genomics, behavioural ecology, and pollinator health. We employ these four levels of biological integration to study social insects and wild pollinators at multiple evolutionary scales.

The conservation of wild pollinators requires in-depth knowledge of their diversity, habitat requirements, and responses to environmental stress. We conduct long term studies of bee biodiversity across agricultural landscapes and urban land use gradients to determine plant-pollinator associations and the stability of wild bee communities. Historical data and experimental manipulation of farm, forest, and urban settings allows us to determine how bees respond to land use change and human disturbance.

We use molecular phylogeny to highlight species and clades of interest to study the transitions from solitary to social behaviour. We use DNA sequence and fossil calibration points to understand the evolutionary relationships among lineages. Using Bayesian techniques we have elucidated the age and origin of sociality in the carpenter bee subfamily, Xylocopinae. In addition we have used ancestral state reconstruction to test predictions on the role of ecological niche competition on the historical biogeography of the bees. We have uncovered evidence for extinction events which have important implications for our understanding of plant-pollinator co-evolution.

We also have ongoing comparative studies of facultatively social bees, both in North America and abroad, to elucidate the role of local ecology and phylogenetic inertia on the social plasticity of primitively social bees. We conduct comparative studies of brain gene expression using next generation sequencing with an emphasis on understanding regulatory mechanisms of cooperation and conflict in varying social contexts. We study the nutritional ecology of wild bees to determine the plant diversity, habitat requirements, microbiota, and potential pathogens in nest pollen. In addition to the integrated study of small carpenter bee genomics and transcriptomics to understand pollinator health, these studies are developing genomic resources for ongoing research on the genetic and epigenetic underpinnings of parental care and cooperative behaviour in incipiently social species.

Research Areas

UN Goals