Accurately determining avian species limits has been a challenge and a work in progress for
most of a century. It is a fascinating but difficult problem. Under the biological species …

Magnoliaceae, an assemblage of early diverged angiosperms, comprises two subfamilies,
speciose Magnolioideae with approximately 300 species in varying numbers of genera and …

Abstract Seasonal migration of Nearctic‐Neotropical passerine birds may have profound
effects on the diversity and abundance of their host‐associated microbiota. Migratory birds …

Given the availability of genomic data to identify separately evolving groups of organisms,
many researchers establish species limits based on assessments of the extent of gene flow …

Cryptic speciation may occur when reproductive isolation is recent or the accumulation of
morphological differences between sister lineages is slowed by stabilizing selection …

Geographic isolation is a central mechanism of speciation, but perfect isolation of
populations is rare. Although speciation can be hindered if gene flow is large, intermediate …

The application of high‐throughput sequencing to phylogenetic analyses is allowing authors
to reconstruct the true evolutionary history of species. This work can illuminate specific …

While the effects of barriers to dispersal such as population declines, habitat fragmentation,
and geographic distance have been well-documented in terrestrial wildlife, factors impeding …

Disentangling the evolutionary relationships of rapidly radiating clades is often challenging
because of low genetic differentiation and potentially high levels of gene flow among …

Genomic evidence of introgression in natural populations has reinvigorated the study of
hybridization in recent years. Still, it is largely unknown how frequently individual organisms …