Intrinsic postzygotic barriers can play an important and multifaceted role in speciation, but
their contribution is often thought to be reserved to the final stages of the speciation process …

Ecologically mediated selection against hybrids, caused by hybrid phenotypes fitting poorly
into available niches, is typically viewed as distinct from selection caused by epistatic …

Pollinator-driven diversification is thought to be a major source of floral variation in plants.
Our knowledge of this process is, however, limited to indirect assessments of evolutionary …

Speciation genomic studies aim to interpret patterns of genome-wide variation in light of the
processes that give rise to new species. However, interpreting the genomic “landscape” of …

In the formation of species, adaptation by natural selection generates distinct combinations
of traits that function well together. The maintenance of adaptive trait combinations in the …

Compared to those of their parents, are the traits of first-generation (F1) hybrids typically
intermediate, biased toward one parent, or mismatched for alternative parental phenotypes …

Epistasis is often portrayed as unimportant in evolution. While random patterns of epistasis
may have limited effects on the response to selection, systematic directional epistasis can …

Traditional classification of speciation modes has focused on physical barriers to gene flow.
Allopatric speciation with complete reproductive isolation is viewed as the most common …

Divergent selection applied to one or more traits drives local adaptation and may lead to
ecological speciation. Divergent selection on many traits might be termed “multidimensional” …

A major goal of speciation research is to reveal the genomic signatures that accompany the
speciation process. Genome scans are routinely used to explore genome‐wide variation …