Tracking hybrid viability across life stages in a natural avian contact zone

• DOI: 10.1093/evolut/qpad204
• Publication Date: 2023-11-08T22:13:37Z
• Authors: Murielle Ålund; J Carolina Segami...; Yishu Zhu; P Navaneeth Krish...; William Jones; Anna Qvarnström
• Keywords: Hybrid zone; Reproductive isolation; Genetic load

Abstract Hybrid inviability is an important post-zygotic reproductive barrier between species, but emerging signs of reduced viability can be difficult to study across the lifespan natural hybrids. We use a combination long-term monitoring, extra-pair paternity, and mitochondrial DNA identification in hybrid zone Ficedula flycatchers detect intrinsic their entire lifespan. evaluate possible evidence Darwin’s corollary Haldane’s rule, predicting asymmetries hybrids resulting from reciprocal crosses, due incompatible genetic factors with sex-specific inheritance patterns. found higher hatching failure among mixed-species pairs, possibly indicating early developmental impairments associated specific parental combinations. Adult had basal mortality rate than both species different age-specific trajectories. There were differences age-independent rates crosses: pied flycatcher mother experienced slightly increased later life. Using exceptional dataset many tracked life stages, we provide for several viability. Incompatibilities alleles located on autosomes uniparentally inherited such as Z-linked and/or genes are strong candidates underlying dysfunction this system.