The classification of reproductive isolating barriers laid out by Dobzhansky and Mayr has
motivated and structured decades of research on speciation. We argue, however, that this …

Contact zones exemplify a series of stages in speciation. In unimodal hybrid zones
intermediates predominate; in bimodal zones hybrids are rare and parental forms …

The tools of molecular genetics have enormous potential for clarifying the nature and age of
species boundaries in marine organisms. Below I summarize the genetic implications of …

Quercus is one of the most abundant and economically important genera of woody plants in
the Northern Hemisphere. To infer phylogenetic relationships within Quercus subgenus …

The nature and timing of evolution of niche differentiation among closely related species
remains an important question in ecology and evolution. The American live oak clade …

Two genetically differentiated forms of fall armyworm, Spodoptera frugiperda (JE Smith), use
different graminaceous host plants, coexist sympatrically throughout their ranges, yet seem …

The use of molecular genetic techniques is becoming increasingly widespread in analyses
of hybrid zones. Yet, exactly how many molecular markers are required to provide a given …

The three members of the Montastraea annularis complex (M. annularis, M. franksi, and M.
faveolata) are dominant reef builders in the western Atlantic whose species status has been …

Oaks (Quercus L.) have long been suspected to hybridize in nature, and widespread genetic
exchange between morphologically defined species is well documented in two-to six …

Background Analysis of interspecific gene flow is crucial for the understanding of speciation
processes and maintenance of species integrity. Oaks (genus Quercus, Fagaceae) are …