Background Postzygotic isolation in the form of reduced viability and/or fertility of hybrids may help maintain species boundaries in the face of interspecific gene flow. Past hybridization events between ...

Sperm morphology is highly diversified among species and at higher taxonomic levels. In birds, there is also increasing evidence of geographical differentiation in sperm traits within species, especially in those with ...

Background One of the biggest challenges in avian taxonomy is the delimitation of allopatric species because their reproductive incompatibility cannot be directly studied in the wild. Instead, reproductive ...

The assessment of evolutionary divergences within subspecies complexes provide an effective short-cut for estimating intraspecific genetic diversity, which is relevant for conservation actions. We explore new evidence ...

Background The great variety in sequence, length, complexity, and abundance of satellite DNA has made it difficult to ascribe any function to this genome component. Recent studies have shown that satellite ...

Divergent sexual selection within allopatric populations may result in divergent sexual phenotypes, which can act as reproductive barriers between populations upon secondary contact. This hypothesis has been most tested ...

Telomere length is related to aging in many eukaryotes and the rate of telomere attrition has been suggested to reflect individual genetic quality. Telomere length could thus have implications for mate choice. We investigated ...

Previous studies based on single mitochondrial markers have shown that the common raven (Corvus corax) consists of two highly diverged lineages that are hypothesised to have undergone speciation reversal upon secondary ...

Mitochondrial DNA usually shows low sequence variation within and high sequence divergence among species, which makes it a useful marker for phylogenetic inference and DNA barcoding. A previous study on the common redstart ...

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, birds exhibit less polymorphism on the ...