Abstract Theory and empirical patterns suggest a disproportionate role for sex chromosomes
in evolution and speciation. Focusing on ZW sex determination (females ZW, males ZZ; the …

Abstract According to Haldane's Rule, the heterogametic sex will show the greatest fitness
reduction in a hybrid cross. In birds, where sex is determined by a ZW system, female …

Why females assess ornaments when choosing mates remains a central question in
evolutionary biology. We hypothesize that the imperative for a choosing female to find a …

Background Evolutionary processes, including selection and differential fitness, shape the
introgression of genetic material across a hybrid zone, resulting in the exchange of some …

Hybrids between species are often sterile or inviable. Hybrid unfitness usually evolves first in
the heterogametic sex—a pattern known as Haldane's rule. The genetics of Haldane's rule …

Interspecific crossing experiments have shown that sex chromosomes play a major role in
reproductive isolation between many pairs of species. However, their ability to act as …

Characterising genetic diversity and structure of populations is essential for effective
conservation of threatened species. The Greater Spotted Eagle (Clanga clanga), a large and …

Introduction Incomplete lineage sorting and hybridization are two major nonexclusive
causes of haplotype sharing between species. Distinguishing between these two processes …

Haldane's rule predicts that particularly high fitness reduction should affect the
heterogametic sex of interspecific hybrids. Despite the fact that hybridization is widespread …

Recent multilocus studies of congeneric birds have shown a pattern of elevated interspecific
divergence on the Z chromosome compared to the autosomes. In contrast, intraspecifically …