Habitat Association Predicts Population Connectivity and Persistence in Flightless Beetles: A Population Genomics...

Area of Science:

• Evolutionary biology
• Population genetics
• Island biogeography

Background:

• Habitat association influences dispersal and evolutionary trajectories.
• The Habitat Constraint hypothesis predicts distinct patterns for stable vs. dynamic habitat specialists.
• Empirical evidence, especially in flightless insects, is limited and controversial.

Purpose of the Study:

• To investigate the effect of habitat association on population dynamics in two closely related flightless beetle lineages.
• To test predictions of the Habitat Constraint hypothesis using comparative population genomics.
• To understand how habitat stability influences gene flow, population bottlenecks, and evolutionary divergence.

Main Methods:

• Genome-wide SNP data analysis.
• Comparative population genomic and demographic analyses.
• Assessment of inter-island gene flow and population bottlenecks.

Main Results:

• Higher inter-island gene flow observed in the psammophilous (dynamic sand) lineage compared to the geophilous (stable soil) lineage.
• Consistent population bottlenecks detected in the psammophilous lineage, indicating local extinction and recolonization.
• Demographic processes were uniform in the psammophilous lineage but varied in the geophilous lineage based on island connectivity.

Conclusions:

• Habitat stability significantly impacts evolutionary dynamics beyond just dispersal traits.
• Dynamic habitats, like sand dunes, can lead to more uniform evolutionary trajectories due to recurrent demographic events.
• The study extends the Habitat Constraint hypothesis by highlighting the role of physical habitat properties and demographic processes.