The utility of writing assignments in undergraduate bioscience.

We tested the hypothesis that engagement in a few, brief writing assignments in a nonmajors science course can improve student ability to convey critical thought about science. A sample of three papers written by students (n = 30) was coded for presence and accuracy of elements related to scientific writing. Scores for different aspects of scientific writing were significantly correlated, suggesting that students recognized relationships between components of scientific thought.

Allochronic isolation and incipient hybrid speciation in tiger swallowtail butterflies.

Hybridization leading to reproductively isolated, novel genotypes is poorly understood as a means of speciation and few empirical examples have been studied. In 1999, a previously non-existent delayed flight of what appeared to be the Canadian tiger swallowtail butterfly, Papilio canadensis, was observed in the Battenkill River Valley, USA. Allozyme frequencies and morphology suggest that this delayed flight was the product of hybridization between Papilio canadensis and its sibling species Papilio glaucus.