D. E. Irwin

Evidence for ancient selective sweeps followed by differentiation among three species of Sphyrapicus sapsuckers

The paper examines genomic differentiation among three sapsucker species, finding high differentiation on the Z chromosome and suggesting a model of speciation involving selective sweeps and local adaptation.

Extreme sex chromosome differentiation, likely driven by inversion, contrasts with mitochondrial paraphyly between species of crowned sparrows

The paper examines genomic differentiation between sympatric sparrow species, finding extreme sex chromosome differentiation driven by inversion, contrasting with mitochondrial paraphyly.

Population genomics of an emergent tri-species hybrid zone

The paper studies a tri-species hybrid zone among three woodpecker species, finding hybridization is more extensive than in two-species zones but constrained to contact zones, suggesting selection against hybrids maintains species boundaries.

Ongoing production of low-fitness hybrids limits range overlap between divergent cryptic species

The paper examines hybridization between two wren species, finding low-fitness hybrids and limited range overlap due to reproductive isolation.

Signatures of mito-nuclear coevolution in a warbler species complex

The paper identifies mitonuclear co-adaptation in warblers by showing a chromosome 5 region associated with mtDNA haplotypes and climate-related selection.

Selection on a pleiotropic color gene block underpins early differentiation between two warbler species

The paper identifies a pleiotropic gene block associated with plumage coloration that drives early differentiation between two hybridizing warbler species.

Assortative mating in hybrid zones is remarkably ineffective in promoting speciation

The paper simulates hybrid zones to show that assortative mating is less effective than postzygotic isolation in preventing species blending.