Random Mating in a Hybrid Zone Between Two Putative Climate-Adapted Bird Lineages With Predicted Mitonuclear...

Area of Science:

• Evolutionary Biology
• Genetics
• Ornithology

Background:

• Mitonuclear interactions are crucial for evolution, adaptation, and speciation.
• Diverged mitonuclear genotypes in Eastern Yellow Robins suggest potential co-adaptation.
• Understanding reproductive isolation mechanisms is key to explaining lineage divergence.

Purpose of the Study:

• To investigate the role of pre-mating isolation in maintaining functional mitonuclear interactions.
• To test if non-random mate-pairing influences lineage divergence in Eastern Yellow Robins.
• To determine if divergence is driven by intrinsic incompatibilities or extrinsic selection.

Main Methods:

• Analysis of field, Z-linked, and mitolineage data from hybrid zones of Eastern Yellow Robins.
• Testing for non-random mating patterns with respect to mitolineage and Z-linked variation.
• Comparison of observed mating patterns with simulations to infer drivers of divergence.

Main Results:

• No evidence of non-random mating was found between lineages with diverged mitonuclear genotypes.
• Observed population genetic patterns are inconsistent with pre-mating isolation mechanisms.
• Findings suggest that reduced female gene flow acting post-mating drives lineage divergence.

Conclusions:

• Pre-mating isolation does not appear to maintain functional mitonuclear interactions in this system.
• Divergence drivers are likely post-mating incompatibilities or selection, rather than mate choice.
• Future research should focus on female-biased mortality and habitat selection to clarify mechanisms.