Bombus franklini population genomics

The Franklin bumble bee (Bombus franklini), one of the rarest US pollinators, exemplifies the challenges facing species with small ranges and declining populations that are no longer found in the wild. Using advanced genomic techniques on historical museum specimens, we reconstructed the species' genetic and demographic history, revealing critically low genetic diversity and significant population declines since the Late Pleistocene. We found that, contrary to previous hypotheses, pathogens likely did not drive the initial decline; rather, its extinction vulnerability may have arisen from multiple population bottlenecks and environmental stochasticity over the last 100,000 years. This study underscores the significance of natural history collections in unraveling species' historical dynamics before modern anthropogenic influences and as a valuable tool for guiding species conservation priorities.