Victor August Zullo, 1936-1993

Victor August Zullo biography, with introduction by Warren D. Allmon and bibliography compiled by Roger W. Portell

Patterns and processes in the history of body size in turritelline gastropods, Jurassic to Recent

Body size is an important trait with implications for energy use and ecology as well as generation time and evolutionary rates. Turritelline gastropods are widely distributed through geologic time and space, making them an excellent group for evaluating macroevolutionary patterns. To evaluate the pattern of body-size change in turritelline gastropods, we compiled a dataset of shell lengths of 316 species of turritelline gastropods spanning the Jurassic to Recent. Type specimens were almost always significantly larger than specimen distributions from the same species. We found that turritelline gastropod size was inversely correlated with latitude, a trend likely driven by the Neogene-Recent diversification of small-bodied Southern Hemisphere taxa. A time series model was applied to distinguish among three possible macroevolutionary patterns: unbiased random walk (no directional trend), biased random walk (directional trend), and stasis (no net change). We determined that turritelline gastropods have experienced stasis in body size throughout their evolutionary history, adding to the growing literature documenting directionless body-size trends in marine invertebrate clades. Stasis of geographically widespread clades may be the result of ecological variability across the environmental range occupied by the group or differential diversification into opposing environments. Turritelline life-history patterns, especially their reproductive strategy that combines a short life span and decline in growth rate around 1 year of age to reallocate energy to reproduction, might circumvent selection for longevity and larger size, while further decrease in minimum size is likely limited by feeding efficiency and anti-predatory defense. The expectation that species or clades should continue to evolve to occupy larger size classes conflicts with the evolutionary advantages of small size, which in turritelline gastropods include high generational turnover and larger population sizes that yield opportunities for genetic variance

Hierarchy Theory of Evolution and the Extended Evolutionary Synthesis: Some Epistemic Bridges, Some Conceptual Rifts

Contemporary evolutionary biology comprises a plural landscape of multiple co-existent conceptual frameworks and strenuous voices that disagree on the nature and scope of evolutionary theory. Since the mid-eighties, some of these conceptual frameworks have denounced the ontologies of the Modern Synthesis and of the updated Standard Theory of Evolution as unfinished or even flawed. In this paper, we analyze and compare two of those conceptual frameworks, namely Niles Eldredge’s Hierarchy Theory of Evolution (with its extended ontology of evolutionary entities) and the Extended Evolutionary Synthesis (with its proposal of an extended ontology of evolutionary processes), in an attempt to map some epistemic bridges (e.g. compatible views of causation; niche construction) and some conceptual rifts (e.g. extra-genetic inheritance; different perspectives on macroevolution; contrasting standpoints held in the “externalism–internalism” debate) that exist between them. This paper seeks to encourage theoretical, philosophical and historiographical discussions about pluralism or the possible unification of contemporary evolutionary biology

Investigating insecticides in water and sediment of the Choapa River, Chile: do they sink or swim?

In Chile, freshwater rivers travel short distances from the Andes Mountains to the Pacific Ocean. The areas immediately adjacent to the rivers are used to produce fruits and vegetables, and it is possible that these areas can contribute insecticides and herbicides to the riverine systems during rainstorm runoff events. The paucity of knowledge about the occurrence and environmental fate of pesticides in these novel systems presents a unique challenge for ecotoxicology. In the Choapa River, we have found that a native pencil catfish, the (Trichomycterus areolatus) exhibits alterations in gene expression. The alterations are occurring in genes that are biomarkers for endocrine function as well as oxidative stress. Given the biological evidence, we sought to determine 1) whether pesticides detected in the Choapa River were consistent with the changes observed in the fish biomarkers, and 2) whether these agrichemicals were predominately found in surface waters or sediment. To address this objective, we collected water and sediment samples from 5 different sites along the Choapa River, then analyzed for a suite of 27 common herbicides, insecticides and their metabolites. Water and sediment samples were prepared onsite then analyzed at the Water Science Lab, University of Nebraska Lincoln, using gas chromatography–mass spectrometry (GC-MS). Preliminary analysis detected the herbicides propazine and metribuzin, as well as the insecticide carbofuran, all of which varied seasonally and spatially within the Choapa River. Finding from our chemical analysis and observations of seasonal and El Nino trends reveal a complex interplay between agrichemical occurrence and river discharge in the Choapa Basin. Additionally, the results of this study illustrate the challenges of analytical environmental chemistry in unique environments, and the importance of appropriate sample schemes of water and sediment

Cervicovaginal and Rectal Fluid as a Surrogate Marker of Antiretroviral Tissue Concentration: Implications for Clinical Trial Design

Quantifying tissue drug concentrations can yield important information during drug development, but complicates pharmacokinetic study design. Mucosal fluids collected by direct aspiration(cervicovaginal fluid; CVF) or swab(rectal fluid; RF) might be used as tissue concentration surrogates, but these relationships are not well characterized

Evidence for Nearby Supernova Explosions

Supernova explosions are one of the most energetic--and potentially lethal--phenomena in the Universe. Scientists have speculated for decades about the possible consequences for life on Earth of a nearby supernova, but plausible candidates for such an event were lacking. Here we show that the Scorpius-Centaurus OB association, a group of young stars currently located at~130 parsecs from the Sun, has generated 20 SN explosions during the last 11 Myr, some of them probably as close as 40 pc to our planet. We find that the deposition on Earth of 60Fe atoms produced by these explosions can explain the recent measurements of an excess of this isotope in deep ocean crust samples. We propose that ~2 Myr ago, one of the SNe exploded close enough to Earth to seriously damage the ozone layer, provoking or contributing to the Pliocene-Pleistocene boundary marine extinction.Comment: 4 pages, 2 figures. Replaced by final version to appear in Physical Review Letter

Can Future Managers and Business Executives be Influenced to Behave more Ethically in the Workplace? The Impact of Approaches to Learning on Business Students’ Cheating Behavior

This study considers the potential for influencing business students to become ethical managers by directing their undergraduate learning environment. In particular, the relationship between business students’ academic cheating, as a predictor of workplace ethical behavior, and their approaches to learning is explored. The three approaches to learning identified from the students’ approaches to learning literature are deep approach, represented by an intrinsic interest in and a desire to understand the subject, surface approach, characterized by rote learning and memorization without understanding, and strategic approach, associated with competitive students whose motivation is the achievement of good grades by adopting either a surface or deep approach. Consistent with the hypothesized theoretical model, structural equation modeling revealed that the surface approach is associated with higher levels of cheating, while the deep approach is related to lower levels. The strategic approach was also associated with less cheating and had a statistically stronger influence than the deep approach. Further, a significantly positive relationship reported between deep and strategic approaches suggests that cheating is reduced when deep and strategic approaches are paired. These findings suggest that future managers and business executives can be influenced to behave more ethically in the workplace by directing their learning approaches. It is hoped that the evidence presented may encourage those involved in the design of business programs to implement educational strategies which optimize students’ approaches to learning towards deep and strategic characteristics, thereby equipping tomorrow’s managers and business executives with skills to recognize and respond appropriately to workplace ethical dilemmas.</p