Hearing in Two Closely Related Species ( and ).

The genus has been extensively used as a model for ecological, behavioral, and evolutionary investigations. We used auditory brainstem responses (ABRs), craniofacial morphology, and pinna measurements to compare characteristics that impact hearing in two wild-caught species, . We observed significant statistical differences in craniofacial and pinna attributes between species with overall exhibiting larger features than .

Climate cycling did not affect haplotype distribution in an abundant Southern African avian habitat generalist species, the familiar chat (Oenanthe familiaris).

Avian species diversity in Southern Africa is remarkably high, yet the mechanisms responsible for that diversity are poorly understood. While this is particularly true with respect to species endemic to the subregion, it is unclear as to how more broadly distributed African species may have colonized southern Africa. One process that may in part account for the high bird species diversity in southern Africa is a "species pump" model, wherein the region was repeatedly colonized by lineages from areas further north: a pattern related to climate cycling and the eastern African arid corridor.

Why Do Some Lineages Radiate While Others Do Not? Perspectives for Future Research on Adaptive Radiations.

Understanding the processes that drive phenotypic diversification and underpin speciation is key to elucidating how biodiversity has evolved. Although these processes have been studied across a wide array of clades, adaptive radiations (ARs), which are systems with multiple closely related species and broad phenotypic diversity, have been particularly fruitful for teasing apart the factors that drive and constrain diversification. As such, ARs have become popular candidate study systems for determining the extent to which ecological features, including aspects of organisms and the environment, and inter- and intraspecific interactions, led to evolutionary diversification.

Hybridization and Transgressive Evolution Generate Diversity in an Adaptive Radiation of Anolis Lizards.

Interspecific hybridization may act as a major force contributing to the evolution of biodiversity. Although generally thought to reduce or constrain divergence between 2 species, hybridization can, paradoxically, promote divergence by increasing genetic variation or providing novel combinations of alleles that selection can act upon to move lineages toward new adaptive peaks. Hybridization may, then, play a key role in adaptive radiation by allowing lineages to diversify into new ecological space.