Levels of genetic differentiation between populations can be highly variable across the
genome, with divergent selection contributing to such heterogeneous genomic divergence …

Incompatibilities in interspecific hybrids, such as sterility and lethality, are widely observed
causes of reproductive isolation and thus contribute to speciation. Because hybrid …

The origin of biological diversity, via the formation of new species, can be inextricably linked
to adaptation to the ecological environment. Specifically, ecological processes are central to …

Reinforcement, the evolution of prezygotic reproductive barriers by natural selection in
response to maladaptive hybridization, is one of the most debated processes in speciation …

Twenty-first century technology is addressing many of the questions posed by 20th-century
biology. Although the new approaches, especially those involving genomic data and …

Bracken ferns (genus Pteridium) represent an ancient species complex with a natural
worldwide distribution. Pteridium has historically been treated as comprising a single …

Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear
genome. This lack of genome sequence information significantly impedes our ability to …

In several cases, estimates of gene flow between species appear to be higher than we might
predict given the strength of interspecific barriers separating these species pairs. However …

Hybridization in isolated populations can lead either to hybrid breakdown and extinction or
in some cases to speciation. The basis of hybrid breakdown lies in genetic incompatibilities …

The fern Ceratopteris richardii has been studied as a model organism for over 50 years
because it is easy to grow and has a short life cycle. In particular, as the first homosporous …