Assessing the impacts of habitat fragmentation on the genetic diversity and adaptive potential of insect pollinators

Many insect species are undergoing rapid population decline in recent decades due to anthropogenic changes to natural landscapes and climate. Pollinator declines in particular may have especially far reaching effects due to the services they provide to plant communities. Understanding how habitat fragmentation differentially impacts these species is vital for performing proper conservation action in such complex communities. Landscape level studies on these impacts have previously overlooked the evolutionary implications of these land use changes on populations and how they may affect their ability to adapt to changing environments. To address this, I will compare highly fragmented and largely continuous semi-natural grasslands, examining how genetic diversity and adaptive potential varies in these environments for pollinators.

I will measure changes in genetic diversity and prevalence of deleterious mutations in insect pollinators sampled before and after the onset of large scale human disturbances within Sweden in habitats of varying fragmentation. To do this I will sample whole genomic data from modern field and historical museum specimens, comparing the diversity present in the past with what I sample in contemporary populations, and how this differs with changes in habitat continuity.

Additionally, as adaptive potential is constrained by the phenotypic variation present in the population, I will examine the evolvability of several morphological features, and how this differs between populations. For all these analyses, I will focus initially on a common generalist - the Common Blue Butterfly, Polyommatus icarus - and expand into other species, potentially a more specialist butterfly species or solitary bees.
This project is financed by the Strategic Research Area BECC.