Gene Flow Accompanies Divergence in Beringian Birds

Area of Science:

• Evolutionary biology
• Genomics
• Ornithology

Background:

• Biodiversity generation and maintenance are driven by population divergence and speciation.
• Beringia, a region shaped by Pleistocene glacial cycles, has a history of population isolation and reconnection, particularly affecting avian populations.
• Previous research indicates gene flow plays a significant role in the divergence of Beringian birds.

Purpose of the Study:

• To investigate divergence, gene flow, and speciation in Beringian avian lineages.
• To test demographic history models for 11 avian lineages across five orders.
• To enhance understanding of avian diversity generation in Beringia.

Main Methods:

• Sequencing of an average of 3710 ultraconserved element (UCE) loci from nuclear genomes.
• Analysis of population-, subspecies-, and species-level pairwise comparisons.
• Application of diffusion analysis for demographic inference (δaδi) to test divergence models.

Main Results:

• All inferred best-fit models of divergence incorporated gene flow.
• Genetic differentiation was examined across 11 avian lineages.
• Demographic history models were tested using population genetic data.

Conclusions:

• Divergence with gene flow is the predominant mode of divergence and speciation in Beringian birds.
• This finding corroborates previous research on Beringian avian populations.
• The study provides insights into the evolutionary processes shaping avian diversity in the region.