Biology Commons^™

Multiple Evolutionary Origins Of Ubiquitous Cu2+ And Zn2+ Binding In The S100 Protein Family, Lucas C. Wheeler, Micah T. Donor, James S. Prell, Michael J. Harms

Faculty Publications - Department of Biological & Molecular Science

The S100 proteins are a large family of signaling proteins that play critical roles in biology and disease. Many S100 proteins bind Zn2+, Cu2+, and/or Mn2+ as part of their biological functions; however, the evolutionary origins of binding remain obscure. One key question is whether divalent transition metal binding is ancestral, or instead arose independently on multiple lineages. To tackle this question, we combined phylogenetics with biophysical characterization of modern S100 proteins. We demonstrate an earlier origin for established S100 subfamilies than previously believed, and reveal that transition metal binding is widely distributed across the tree. Using isothermal titration calorimetry, …

Measuring The Robustness Of Network Community Structure Using Assortativity, Daizaburo Shizuka, Damien R. Farine

School of Biological Sciences: Faculty Publications

The existence of discrete social clusters, or ‘communities’, is a common feature of social networks in human and nonhuman animals. The level of such community structure in networks is typically measured using an index of modularity, Q. While modularity quantifies the degree to which individuals associate within versus between social communities and provides a useful measure of structure in the social network, it assumes that the network has been well sampled. However, animal social network data is typically subject to sampling errors. In particular, the associations among individuals are often not sampled equally, and animal social network studies are often …

Effects Of Temporal Variation In Temperature And Density Dependence On Insect Population Dynamics, C. V. Haridas, Lance J. Meinke, Bruce E. Hibbard, Blair D. Siegfried, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Understanding the effects of environmental variation on insect populations is important in light of predictions about increasing climatic variability. This paper uses the univoltine western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte) as a case study and employs deterministic and stochastic modeling to evaluate how insect population dynamics is shaped by density-dependent survival and annual variation in temperature, which are key in regulating insect populations. Field data showed that larval survival varied significantly between years but was constant for a range of densities. Survival dropped only beyond a threshold density, a feature resembling generalized Ricker functions used in modeling density-dependent …

Signal Traits And Oxidative Stress: A Comparative Study Across Populations With Divergent Signals, Maren N. Vitousek, Oldřich Tomášek, Tomáš Albrecht, Matt Wilkins, Rebecca Safran

School of Biological Sciences: Faculty Publications

Diverging populations often shift patterns of signal use – a process that can contribute to reproductive isolation and speciation. Yet it is not clear why most traits gain or lose signal value during divergence. One reason this could occur is because changes in the relationship between signals and relevant physiological parameters degrade the reliability of a signal, or even change its underlying information content. Here we test the hypothesis that the relationship between signal trait elaboration and a central component of organismal health – oxidative stress – differs across closely related populations that have diverged in signal use and preferences. …

Expanding The Limits Of Thermoacidophily In The Archaeon Sulfolobus Solfataricus By Adaptive Evolution, Samuel Mccarthy, Tyler Johnson, Benjamin J. Pavlik, Sophie Payne, Wendy Schackwitz, Joel Martin, Anna Lipzen, Erica Keffeler, Paul H. Blum

School of Biological Sciences: Faculty Publications

Extremely thermoacidophilic Crenarchaeota belonging to the order Sulfolobales flourish in hot acidic habitats that are strongly oxidizing. The pH extremes of these habitats, however, often exceed the acid tolerance of type species and strains. Here, adaptive laboratory evolution was used over a 3-year period to test whether such organisms harbor additional thermoacidophilic capacity. Three distinct cell lines derived from a single type species were subjected to high-temperature serial passage while culture acidity was gradually increased. A 178-fold increase in thermoacidophily was achieved after 29 increments of shifted culture pH resulting in growth at pH 0.8 and 80°C. These strains were …

Genome Sequence Of Streptomyces Aureofaciens Atcc Strain 10762, Julien Gradnigo, Greg Somerville, Michael J. Huether, Richard J. Kemmy, Craig M. Johnson, Michael G. Oliver, Etsuko N. Moriyama

School of Biological Sciences: Faculty Publications

Streptomyces aureofaciens is a Gram-positive actinomycete that produces the antibiotics tetracycline and chlortetracycline. Here, we report the assembly and initial annotation of the draft genome sequence of S. aureofaciens ATCC strain 10762.

Range-Wide Patterns Of Geographic Variation In Songs Of Golden-Crowned Sparrows (Zonotrichia Atricapilla), Daizaburo Shizuka, M. Ross Lein, Glen Chilton

School of Biological Sciences: Faculty Publications

Discrete geographic variation, or dialects, in songs of songbirds arise as a consequence of complex interactions between ecology and song learning. Four of the five species of Zonotrichia sparrows, including the model species White-crowned Sparrow (Z. leucophrys), have been studied with respect to the causes and consequences of geographic variation in song. Within White-crowned Sparrows, subspecies that migrate farther have larger range size of dialects. Here, we assessedgeographic patterns of song variation in the fifth species of this genus, the Golden-crowned Sparrow (Z. atricapilla). We analyzed field-recorded songs from 2 sampling periods (1996–1998 and 2006–2013) covering …

Corrigendum: The Arabidopsis Homologs Of Trithorax (Atx1) And Enhancer Of Zeste (Clf) Establish ‘Bivalent Chromatin Marks’ At The Silent Agamous Locus, Abdelaty Saleh, Ayed Al-Abdallat, Ivan Ndamukong, Raul Alvarez-Venegas, Zoya Avramova

School of Biological Sciences: Faculty Publications

The authors wish to draw the attention to two irregularities in Figures 2a and 4. Both concern errors in duplicating images of "empty" lanes illustrating absence of DNA bands. We regret these omissions and apologize to readers for the inconvenience caused. The results and conclusions remain valid.

Climate Modifies Response Of Non-Native And Native Species Richness To Nutrient Enrichment, Habacuc Flores-Moreno, Peter B. Reich, Eric M. Lind, Lauren L. Sullivan, Eric W. Seabloom, Laura Yahdjian, Andrew S. Macdougall, Lara G. Reichmann, Juan Alberti, Selene Baez, Jonathan D. Bakker, Marc W. Cadotte, Maria C. Caldeira, Enrique J. Chaneton, Carla M. D'Antonio, Philip A. Fay, Jennifer Firn, Nicole Hagenah, W. Stanley Harpole, Oscar Iribarne, Kevin P. Kirkman, Johannes M.H. Knops, Kimberly J. La Pierre, Ramesh Laungani, Andrew D.B. Leakey, Rebecca L. Mcculley, Joslin L. Moore, Jesus Pascual, Elizabeth T. Borer

School of Biological Sciences: Faculty Publications

Ecosystem eutrophication often increases domination by non-natives and causes displacement of native taxa. However, variation in environmental conditions may affect the outcome of interactions between native and non-native taxa in environments where nutrient supply is elevated. We examined the interactive effects of eutrophication, climate variability and climate average conditions on the success of native and non-native plant species using experimental nutrient manipulations replicated at 32 grassland sites on four continents. We hypothesized that effects of nutrient addition would be greatest where climate was stable and benign, owing to reduced niche partitioning. We found that the abundance of non-native species increased …

The Importance Of Cross-Validation, Accuracy, And Precision For Measuring Plumage Color: A Comment On Vaquero-Alba Et Al. (2016), Joanna K. Hubbard, Amanda K. Hund, Iris I. Levin, Kevin J. Mcgraw, Matt Wilkins, Rebecca J. Safran

School of Biological Sciences: Faculty Publications

Vaquero-Alba and colleagues published a study in The Auk: Ornithological Advances comparing objective color measurements of plumage taken in the field directly on a bird’s body to those taken in the lab on collected feathers arranged to emulate the appearance of a bird’s natural plumage. Although the field measures of plumage color were less repeatable than lab measures, the authors concluded that measurements taken in the field were more representative of a bird’s ‘‘true color.’’ Accordingly, they recommend that researchers should bring spectrophotometers into the field to measure color on live birds. We question the assumption that their field measurements …

Biotin Auxotrophy And Biotin Enhanced Germ Tube Formation In Candida Albicans, Nur Ahmad Hussin, Ruvini U. Pathirana, Sahar Hasim, Swetha Tati, Jessica A. Scheib-Owens, Kenneth Nickerson

School of Biological Sciences: Faculty Publications

Due to the increased number of immunocompromised patients, infections with the pathogen Candida albicans have significantly increased in recent years. C. albicans transition from yeast to germ tubes is one of the essential factors for virulence. In this study we noted that Lee’s medium, commonly used to induce filamentation, contained 500-fold more biotin than needed for growth and 40-fold more biotin than is typically added to growth media. Thus, we investigated the effects of excess biotin on growth rate and filamentation by C. albicans in different media. At 37 ˚C, excess biotin (4 µM) enhanced germ tube formation (GTF) ca. …

Polymorphisms And Resistance Mutations Of Hepatitis C Virus On Sequences In The European Hepatitis C Virus Database, Dimas Alexandre Kliemann, Cristiane Valle Tovo, Ana Beatriz Gorini Da Veiga, Angelo Alves De Mattos, Charles Wood

School of Biological Sciences: Faculty Publications

AIM: To evaluate the occurrence of resistant mutations in treatment-naïve hepatitis C virus (HCV) sequences deposited in the European hepatitis C virus database (euHCVdb).

METHODS: The sequences were downloaded from the euHCVdb (https://euhcvdb.ibcp.fr/euHCVdb/). The search was performed for full-length NS3 protease, NS5A and NS5B polymerase sequences of HCV, separated by genotypes 1a, 1b, 2a, 2b and 3a, and resulted in 798 NS3, 708 NS5A and 535 NS5B sequences from HCV genotypes 1a, 1b, 2a, 2b and 3a, after the exclusion of sequences containing errors and/or gaps or incomplete sequences, and sequences from patients previously treated with direct antiviral agents (DAA). …

How Many Kinds Of Birds Are There And Why Does It Matter?, George F. Barrowclough, Joel Cracraft, John Klicka, Robert M. Zink

School of Biological Sciences: Faculty Publications

Estimates of global species diversity have varied widely, primarily based on variation in the numbers derived from different inventory methods of arthropods and other small invertebrates. Within vertebrates, current diversity metrics for fishes, amphibians, and reptiles are known to be poor estimators, whereas those for birds and mammals are often assumed to be relatively well established. We show that avian evolutionary diversity is significantly underestimated due to a taxonomic tradition not found in most other taxonomic groups. Using a sample of 200 species taken from a list of 9159 biological species determined primarily by morphological criteria, we applied a diagnostic, …

Student Buy-In To Active Learning In A College Science Course, Andrew J. Cavanagh, Oriana R. Aragon, Xinnian Chen, Brian A. Couch, Mary F. Durham, Aiyana Bobrownicki, David I. Hanauer, Mark J. Graham

School of Biological Sciences: Faculty Publications

The benefits of introducing active learning in college science courses are well established, yet more needs to be understood about student buy-in to active learning and how that process of buy-in might relate to student outcomes. We test the exposure–persuasion– identification–commitment (EPIC) process model of buy-in, here applied to student (n = 245) engagement in an undergraduate science course featuring active learning. Student buy-in to active learning was positively associated with engagement in self-regulated learning and students’ course performance. The positive associations among buy-in, self-regulated learning, and course performance suggest buy-in as a potentially important factor leading to student …

Characterizing Student Perceptions Of And Buy-In Toward Common Formative Assessment Techniques, Kathleen R. Brazeal, Tanya L. Brown, Brian A. Couch

School of Biological Sciences: Faculty Publications

Formative assessments (FAs) can occur as preclass assignments, in-class activities, or postclass homework. FAs aim to promote student learning by accomplishing key objectives, including clarifying learning expectations, revealing student thinking to the instructor, providing feedback to the student that promotes learning, facilitating peer interactions, and activating student ownership of learning. While FAs have gained prominence within the education community, we have limited knowledge regarding student perceptions of these activities. We used a mixed-methods approach to determine whether students recognize and value the role of FAs in their learning and how students perceive course activities to align with five key FA …

A Guide For Graduate Students Interested In Postdoctoral Positions In Biology Education Research, Melissa L. Aikens, Lisa A. Corwin, Tessa C. Andrews, Brian A. Couch, Sarah L. Eddy, Lisa Mcdonnell, Gloriana Trujillo

School of Biological Sciences: Faculty Publications

Postdoctoral positions in biology education research (BER) are becoming increasingly common as the field grows. However, many life science graduate students are unaware of these positions or do not understand what these positions entail or the careers with which they align. In this essay, we use a backward-design approach to inform life science graduate students of postdoctoral opportunities in BER. Beginning with the end in mind, we first discuss the types of careers to which BER postdoctoral positions lead. We then discuss the different types of BER postdoctoral positions, drawing on our own experiences and those of faculty mentors. Finally, …

Absence Of Mate Choice And Postcopulatory Benefits In A Species With Extreme Sexual Size Dimorphism, Marie Claire Chelini, Eileen Hebets

Eileen Hebets Publications

Most hypotheses related to the evolution of female-biased extreme sexual size dimorphism (SSD) attribute the differences in the size of each sex to selection for reproduction, either through selection for increased female fecundity or selection for male increased mobility and faster development. Very few studies, however, have tested for direct fitness benefits associated with the latter – small male size. Mecaphesa celer is a crab spider with extreme SSD, whose males are less than half the size of females and often weigh 10 times less. Here, we test the hypotheses that larger size in females and smaller size in males …

Knowing Your Own: A Classroom Case Study Using The Scientific Method To Investigate How Birds Learn To Recognize Their Offspring, Joanna K. Hubbard, Daizaburo Shizuka, Brian A. Couch

School of Biological Sciences: Faculty Publications

Understanding the scientific method provides students with a necessary foundation for careers in science-related fields. Moreover, students can apply scientific inquiry skills in many aspects of their daily lives and decision making. Thus, the ability to apply the scientific method represents an essential skill that students should learn during undergraduate science education. We designed an interrupted case study in which students learn about and apply the scientific method to investigate and recapitulate the findings of a published research article. This research article addresses the question of how parents recognize their own young in a system where birds of the same …

Heterochromatin And Genetic Conflict, Colin D. Meiklejohn

School of Biological Sciences: Faculty Publications

Meiosis is a dangerous business. The two alleles in diploid organisms share an evolutionary interest in the survival and reproduction of their host individual; however, as soon as they segregate into haploid gametes, these alleles find themselves competing for transmission to the next generation (1). In males, the development of all four meiotic products into functional gametes fosters the evolution of alleles that disrupt the development or viability of gametes carrying the alternate allele. Systems that distort Mendelian segregation (hence, segregation distorters) typically comprise at least two loci: a trans-acting drive locus (such as a gene that encodes a …

Unraveling The Consequences Of The Terminal Pleistocene Megafauna Extinction On Mammal Community Assembly, Felisa A. Smith, Catalina P. Tomé, Emma A. Elliott Smith, S. Kathleen Lyons, Seth D. Newsome, Thomas W. Stafford

School of Biological Sciences: Faculty Publications

Recent studies connecting the decline of large predators and consumers with the disintegration of ecosystems often overlook that this natural experiment already occurred. As recently as 14 ka, tens of millions of large-bodied mammals were widespread across the American continents. Within 1000 yr of the arrival of humans, ∼80% were extinct including all > 600 kg. While the cause of the late Pleistocene (LP) extinction remains contentious, largely overlooked are the ecological consequences of the loss of millions of large-bodied animals. Here, we examine the influence of the LP extinction on a local mammal community. Our study site is Hall’s Cave …

Comparative Anatomy Of The Bony Labyrinth Of Extant And Extinct Porpoises (Cetacea: Phocoenidae), Rachel A. Racicot, William Gearty, Naoki Kohno, John J. Flynn

School of Biological Sciences: Faculty Publications

The inner ear anatomy of cetaceans, now more readily accessible by means of nondestructive high-resolution X-ray computed tomographic (CT) scanning, provides a window into their acoustic abilities and ecological preferences. Inner ear labyrinths also may be a source for additional morphological characters for phylogenetic analyses. In this study, we explore digital endocasts of the inner ear labyrinths of representative species of extinct and extant porpoises (Mammalia: Cetacea: Phocoenidae), a clade of some of the smallest odontocete cetaceans, which produce some of the highest-frequency clicks for biosonar and communication. Metrics used to infer hearing ranges based on cochlear morphology indicate that …

Two New Species Of Geosesarma De Man, 1892 (Crustacea: Brachyura: Sesarmidae) From Palawan, The Philippines, Hendrik Freitag, Marivene Manuel-Santos, Peter K.L Ng

Biology Faculty Publications

Two new and relatively large species of semi-terrestrial sesarmid crabs of the genus Geosesarma De Man, 1892, are described from Palawan Island, Philippines. They are distinguishable from congeners by the characteristic structure of their carapace, chelipeds, ambulatory legs and male first gonopods. Aspects of their ecology are briefly discussed

Biotechnology/Cloning Poster, Hye Tae Kim

A with Honors Projects

This is a student project, panels used to construct a poster on biotechnology and cloning provides a brief overview of the topic, including a timeline of the history of cloning.

In Vitro Transcription Lab, Sarah Oh, Samantha Christ

A with Honors Projects

This is a lab and worksheet created by students of Biology 141 as a project for the A with Honors Program. to demonstrate transcription from DNA to RNA. After completing this exercise, the student should be able to distinguish between yields after electrophoresis, describe which varied substance contributed to the largest yield, and describe the importance of not contaminating the sample.

Synthetic Biology Open Language (Sbol) Version 2.1.0, Zhen Zhang

Integrative Biology Faculty and Staff Publications

Synthetic biology builds upon the techniques and successes of genetics, molecular biology, and metabolic engineering by applying engineering principles to the design of biological systems. The field still faces substantial challenges, including long development times, high rates of failure, and poor reproducibility. One method to ameliorate these problems would be to improve the exchange of information about designed systems between laboratories. The Synthetic Biology Open Language (SBOL) has been developed as a standard to support the specification and exchange of biological design information in synthetic biology, filling a need not satisfied by other pre-existing standards. This document details version 2.1 …

Effects Of Nutrient Supplementation On Host-Pathogen Dynamics Of The Amphibian Chytrid Fungus: A Community Approach, Julia C. Buck, Jason R. Rohr, Andrew R. Blaustein

Integrative Biology Faculty and Staff Publications

1. Anthropogenic stressors may influence hosts and their pathogens directly or may alter host–pathogen dynamics indirectly through interactions with other species. For example, in aquatic ecosystems, eutrophication may be associated with increased or decreased disease risk. Conversely, pathogens can influence community structure and function and are increasingly recognised as important members of the ecological communities in which they exist.
2. In outdoor mesocosms, we experimentally manipulated nutrients (nitrogen and phosphorus) and the presence of a fungal pathogen, Batrachochytrium dendrobatidis (Bd), and examined the effects on Bd abundance on larval amphibian hosts (Pseudacris regilla: Hylidae), amphibian traits and community dynamics. We …

An Experiment In Graduate Education: A Marine Science Adventure Across The Indian Ocean, Vicki Buchsbaum Pearse, John C. Ogden, Sharon J. Proctor

Integrative Biology Faculty and Staff Publications

In the fall of 1964, Stanford University’s R/V Te Vega Cruise 5 crossed the equatorial Indian Ocean from Mombasa to Singapore, one of many ships participating in the International Indian Ocean Expedition. The cruise achieved two goals: (1) it provided hands-on oceanography training for graduate students in marine sciences, and (2) it documented the deep scattering layers of the Indian Ocean, only poorly known at the time. Taking place on the other side of the globe from the United States, the cruise also exposed students to cultural and personal experiences that shaped their lives and professions. It demonstrated the importance …

Spatial Spread Of The West Africa Ebola Epidemic, Andrew M. Kramer, J. Tomlin Pulliam, Laura W. Alexander, Andrew W. Park, Pejman Rohani, John M. Drake

Integrative Biology Faculty and Staff Publications

Controlling Ebola outbreaks and planning an effective response to future emerging diseases are enhanced by understanding the role of geography in transmission. Here we show how epidemic expansion may be predicted by evaluating the relative probability of alternative epidemic paths. We compared multiple candidate models to characterize the spatial network over which the 2013–2015 West Africa epidemic of Ebola virus spread and estimate the effects of geographical covariates on transmission during peak spread. The best model was a generalized gravity model where the probability of transmission between locations depended on distance, population density and international border closures between Guinea, Liberia …

Ordination Obscures The Influence Of Environment On Plankton Metacommunity Structure, Tad A. Dallas, Andrew M. Kramer, Marcus Zokan, John M. Drake

Integrative Biology Faculty and Staff Publications

The composition of plankton communities in individual habitats is often influenced by environmental conditions like pH or hydroperiod. At larger scales, environmental gradients can influence community structure across interconnected local communities. Detecting the role of environmental and spatial factors on metacommunity structure depends on the ordering of sites and species prior to analysis. We investigated this ordination in two wetland metacommunities; a well-sampled, hyper-diverse zooplankton metacommunity, and a Central American phytoplankton metacommunity. We calculated coherence, turnover, and boundary clumping to classify the structure of the metacommunity, and we propose a statistic that responds to variation in both coherence and turnover. …

Mathematical Models Are A Powerful Method To Understand And Control The Spread Of Huanglongbing, Rachel A. Taylor, Erin Mordecai, Christopher A. Gilligan, Jason R. Rohr, Leah R. Johnson

Integrative Biology Faculty and Staff Publications

Huanglongbing, or citrus greening, is a global citrus disease occurring in almost all citrus growing regions and causing substantial economic burdens to individual growers, citrus industries and governments. Successful management strategies to reduce disease burden are desperately needed but with so many possible interventions and combinations thereof, it is difficult to know which are worthwhile or cost-effective. We review how mathematical models have yielded useful insights into controlling disease spread for other vector-borne plant diseases, and the small number of mathematical models of Huanglongbing. We adapt a malaria model to Huanglongbing, by including temperature-dependent psyllid traits and economic costs, to …