The bacterium Thioploca ingrica on wet walls in Zion National Park, Utah

Hanging gardens and wet wall habitats have been studied for the past several years in many arid regions of the Intermountain West. One unusual large wet wall habitat in Zion National Park was found to be covered with a mucilaginous red-colored growth of the filamentous gliding bacterium Thioploca ingrica Visloukh. This is the only habitat we have examined where the predominant matrix-forming organism was a bacterium rather than an alga.     

Diatom flora of Beaver Dam Creek, Washington County, Utah, USA

The diatom flora of Beaver Dam Creek, Washington County, Utah, was studied. The study area is in a warm Mojave Desert environment at an elevation between 810 and 850 m. A total of 99 taxa were identified from composite samples taken in the fall, winter, spring, and summer seasons. These taxa are all broadly distributed and no endemic species were encountered. Three new records for the state of Utah were identified: Gomphoneis eriense Skv. & Mayer, Navicula elginensis var. lata. (M. Perag.) Patr., and Nitzschia calida Grun. The most important taxa throughout the study as determined by multiplying percent presence by average relative density (Important Species Index) were Cymbella affinis Kütz., Epithemia sorex Kütz., Navicula veneta Kütz., Nitzschia palea (Kütz.) W. Sm., and Nitzschia microcephala Grun.     

Kuhnian theory-choice and virtue convergence: Facing the base rate fallacy

Perhaps the strongest argument for scientific realism, the no-miracles-argument, has been said to commit the so-called base rate fallacy. The apparent elusiveness of the base rate of true theories has even been said to undermine the rationality of the entire realism debate. On the basis of the Kuhnian picture of theory choice, I confront this challenge by arguing that a theory is likely to be true if it possesses multiple theoretical virtues and is embraced by numerous scientists–even when the base rate converges to zero.