Species tree reconstruction of a poorly resolved clade of salamanders (Ambystomatidae) using multiple nuclear loci.

The analysis of diverse data sets can yield different phylogenetic estimates that challenge systematists to explain the source of discordance. The mole salamanders (family Ambystomatidae) are a classic example of this phylogenetic conflict. Previous attempts to resolve the ambystomatid species tree using allozymic, morphological, and mitochondrial sequence data have yielded different estimates, making it unclear which data source best approximates ambystomatid phylogeny and which ones yield phylogenetically inaccurate reconstructions.

Duration and consistency of historical selection are correlated with adaptive trait evolution in the streamside salamander, Ambystoma barbouri.

A fundamental challenge in evolutionary biology concerns estimating the extent to which ecological trade-offs may impose constraints on adaptive evolution. Novel ecological stressors may limit adaptive evolution of naive lineages that have experienced historically different selective regimes. Regarded as recently derived from a pond-breeding ancestor, streamside salamanders face the novel and strong selection pressure of breeding in streams with fish predators.

Lethal and sublethal effects of atrazine, carbaryl, endosulfan, and octylphenol on the streamside salamander (Ambystoma barbouri).

Agricultural contaminants may be contributing to worldwide amphibian declines, but little is known about which agrichemicals pose the greatest threat to particular species. One reason for this is that tests of multiple contaminants under ecologically relevant conditions are rarely conducted concurrently. In this study, we examined the effects of 37-d exposure to the agrichemicals atrazine (4, 40, and 400 micrograms/L), carbaryl (0.