Biology Commons^™

Testing A Global Standard For Quantifying Species Recovery And Assessing Conservation Impact, Molly K. Grace, John Carroll, 201 Other Scholars

School of Biological Sciences: Faculty Publications

Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a “Green List of Species” (now the IUCN Green Status of Species). A draft Green Status framework for assessing species’ progress toward recovery, published in 2018, proposed 2 separate but interlinked components: a standardized method (i.e., measurement against benchmarks of species’ viability, functionality, and preimpact distribution) to determine current species recovery status (herein species recovery score) and application of that method to estimate past and potential future impacts of conservation based on 4 metrics ( …

Lichens And Biofilms: Common Collective Growth Imparts Similar Developmental Strategies, Erin C. Carr, Steven D. Harris, Joshua R. Herr, Wayne Riekhof

Department of Plant Pathology: Faculty Publications

Lichens are traditionally defined as a symbiotic relationship between fungi and algae and/or cyanobacteria. This union forms a unique structure called the thallus, which attaches to surfaces such as rocks and tree bark. Recent reports challenge the view that lichens are comprised of one fungus and one photobiont, and instead suggest that they are a consortium of microbes. Much of lichen biology remains unknown as most of our knowledge of lichens is limited to morphological characteristics with little to no functional analysis of lichen genes. However, lichens and biofilms share many similar physiological traits which when compared may assist in …

Ogre-Faced, Net-Casting Spiders Use Auditory Cues To Detect Airborne Prey, Jay A. Stafstrom, Gil Menda, Eya I. Nitzany, Eileen A. Hebets, Ronald R. Hoy

Eileen Hebets Publications

Prey-capture behavior among spiders varies greatly from passive entrapment in webs to running down prey items on foot. Somewhere in the middle are the ogre-faced, net-casting spiders (Deinopidae: Deinopis) that actively capture prey while being suspended within a frame web. Using a net held between their front four legs, these spiders lunge downward to ensnare prey from off the ground beneath them. This “forward strike” is sensorially mediated by a massive pair of hypersensitive, night-vision eyes. Deinopids can also intercept flying insects with a “backward strike,” a ballistically rapid, overhead back-twist, that seems not to rely on visual cues. Past …

Trophic Cascades Alter Eco-Evolutionary Dynamics And Body Size Evolution, Thomas M. Luhring, John Delong

School of Biological Sciences: Faculty Publications

Trait evolution in predator–prey systems can feed back to the dynamics of interacting species as well as cascade to impact the dynamics of indirectly linked species (eco-evolutionary trophic cascades; EETCs). A key mediator of trophic cascades is body mass, as it both strongly influences and evolves in response to predator–prey interactions. Here, we use Gillespie ecoevolutionary models to explore EETCs resulting from top predator loss and mediated by body mass evolution. Our four-trophic-level food chain model uses allometric scaling to link body mass to different functions (ecological pleiotropy) and is realistically parameterized from the FORAGE database to mimic the parameter …

Exploring A Novel Substrate-Borne Vibratory Signal In The Wolf Spider Schizocosa Floridana, Malcolm F. Rosenthal, Eileen Hebets, Rowan H. Mcginley, Cody Raiza, James Starrett, Lin Yan, Damian O. Elias

Eileen Hebets Publications

Animals communicate using a diversity of signals produced by a wide array of physical structures. Determining how a signal is produced provides key insights into signal evolution. Here, we examine a complex vibratory mating display produced by male Schizocosa floridana wolf spiders. This display contains three discrete substrate-borne acoustic components (known as “thumps”, “taps”, and “chirps”), each of which is anecdotally associated with the movement of a different body part (the pedipalps, legs, and abdomen respectively). In order to determine the method of production, we employ a combination of high-speed video/audio recordings and SEM imaging of possible sound-producing structures. Previous …

Testing The Hypothesized Antipredator Defence Function Of Stridulation In The Spiny Orb-Weaving Spider, Micrathena Gracilis, Tyler B. Corey, Eileen A. Hebets

Eileen Hebets Publications

The observable diversity of antipredator defenses across organisms demonstrates predation’s impact on trait evolution. The functions of many traits that are presumed to have an antipredator function have never been directly tested. The spiny orb-weaving spider, Micrathena gracilis, for example, stridulates when grasped. While stridulation was first hypothesized to be an antipredator defense nearly 50 years ago, no data exist to support this hypothesis. To explore the form and function of M. gracilis stridulation, we first quantified the behavioral and acoustical properties of sound production. Next, using laboratory assays, we directly tested the effect of stridulation on survival with …

Making A First Impression: Exploring What Instructors Do And Say On The First Day Of Introductory Stem Courses, A. Kelly Lane, Clara L. Meaders, J. Kenny Shuman, Mackenzie R. Stetzer, Erin L. Vinson, Brian A. Couch, Michelle K. Smith, Marilyne Stains

School of Biological Sciences: Faculty Publications

Student impressions formed during the first day of class can impact course satisfaction and performance. Despite its potential importance, little is known about how instructors format the first day of class. Here, we report on observations of the first day of class in 23 introductory science, technology, engineering, and math (STEM) courses. We first described how introductory STEM instructors structure their class time by characterizing topics covered on the first day through inductive coding of class videos. We found that all instructors discussed policies and basic information. However, a cluster analysis revealed two groups of instructors who differed primarily in …

Inheritability Of Ciprofloxacin-Induced Mitochondrial Mutations From Parental To Offspring Generation Using Quantitative Polymerase Chain Reaction, Rose Mccoy

Honors Program: Senior Projects (Public)

In all eukaryotes, mitochondria are known as the powerhouse of the cell (Siekevitz, 1957). In plants, however, their mitochondrial genome is especially strange. Plant mitochondrial genomes are extremely large and contain both linear and circular subgenomic DNA fragments. Plant mitochondrial genomes undergo a significant amount of mutations in the form of rearrangements. However, it is not known how often these rearrangements are inherited by the next generation. It is thought that plant cells that are still dividing have higher rates of DNA repair, such as double-strand break repair, to ensure the quality of that plant lineage. As follows, it is …

Pollinator Assemblage And Pollen Load Differences On Sympatric Diploid And Tetraploid Cytotypes Of The Desert-Dominant Larrea Tridentata, Robert G. Laport, Robert L. Minckley, Diana Pilson

School of Biological Sciences: Faculty Publications

PREMISE: Whole-genome duplication (polyploidy) is an important force shaping flowering plant evolution. Ploidy-specific plant–pollinator interactions represent important community-level biotic interactions that can lead to nonrandom mating and the persistence of mixed-ploidy populations. METHODS: At a naturally occurring diploid–tetraploid contact zone of the autopolyploid desert shrub Larrea tridentata, we combined flower phenology analyses, collections of bees on plants of known cytotype, and flow cytometry analyses of bee-collected pollen loads to investigate whether (1) diploid and tetraploid plants have unique bee pollinator assemblages, (2) bee taxa exhibit ploidy-specific visitation and pollen collection biases, and (3) specialist and generalist bee taxa have ploidy-specific …

Spatial Ecology And Resource Selection Of Bighorn Sheep (Ovis Canadensis) Ewes In A Prairie Badlands Population, Erin Wood

School of Natural Resources: Dissertations, Theses, and Student Research

The basic spatial ecology and habitat relationships of female bighorn sheep in Nebraska are poorly understood. Establishing seasonal patterns of space use and resource selection for this population at the margin of their historical and current range addresses a key knowledge gap and provides important baseline information for ongoing conservation efforts in Nebraska. We deployed GPS radio-collars on 56 adult ewes in western Nebraska to quantify seasonal space use, movements, and resource selection of ewes. To investigate spatial ecology, we quantified movements of ewes and the factors that influence home range size, seasonal use, and spatial stability across seasons. Home …

Ornate Box Turtles (Terrapene Ornata) Copulating In Water: An Incidental Observation Or Ancestral Behavior, Ashley Forrester, Michael Rohde, Mary Harner, Carter Kruse, Keith Geluso

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Herein, we report the first observation of the terrestrial Ornate Box Turtle (Terrapene ornata) copulating in water. To understand whether such an event reflected an isolated incident, we compiled observations reported in the literature of copulatory behaviors in water for other North American turtles. Our literature review revealed that other species of box turtles in North America, the Coahuilan Box Turtle (Terrapene coahuila) and Gulf Coast Box Turtle (Terrapene carolina major), occasionally also copulate in water. The vast majority of turtles in North America copulate in water, as most are semi-aquatic, including all species …

Optimal Allocation Of Two Resources In Annual Plants, David Mcmorris

Department of Mathematics: Dissertations, Theses, and Student Research

The fitness of an annual plant can be thought of as how much fruit is produced by the end of its growing season. Under the assumption that annual plants grow to maximize fitness, we can use techniques from optimal control theory to understand this process. We introduce two models for resource allocation in annual plants which extend classical work by Iwasa and Roughgarden to a case where both carbohydrates and mineral nutrients are allocated to shoots, roots, and fruits in annual plants. In each case, we use optimal control theory to determine the optimal resource allocation strategy for the plant …

Resources For Teaching And Assessing The Vision And Change Biology Core Concepts, Janet L. Branchaw, Pamela A. Pape-Lindstrom, Kimberly D. Tanner, Sarah A. Bissonnette, Tawnya L. Cary, Brian A. Couch, Alison J. Crowe, Jenny K. Knight, Katharine Semsar, Julia I. Smith, Michelle K. Smith, Mindi M. Summers, Caroline J. Wienhold, Christian D. Wright, Sara E. Brownell

School of Biological Sciences: Faculty Publications

The Vision and Change report called for the biology community to mobilize around teaching the core concepts of biology. This essay describes a collection of resources developed by several different groups that can be used to respond to the report’s call to transform undergraduate education at both the individual course and departmental levels. First, we present two frameworks that help articulate the Vision and Change core concepts, the BioCore Guide and the Conceptual Elements (CE) Framework, which can be used in mapping the core concepts onto existing curricula and designing new curricula that teach the biology core concepts. Second, we …

Book Review: Nature’S Giants: The Biology And Evolution Of The World’S Largest Lifeforms., William Gearty

School of Biological Sciences: Faculty Publications

We as humans have always been in awe of big things, whether they are in space, the oceans, or the fossil record. Ruxton uses this inspiration as the entry point to explore the biology (and even physics) and evolu- tion of large animals in Nature’s Giants, covering nu- merous great lifeforms spanning from giant whales to enormous sauropods. Although readers may ini- tially be drawn in by the size of these creatures, as the author writes in the introduction, “size matters,” and the weight of these animals brings with it many other fascinating implications that he goes into with moderate …

Origin Of Complexity In Hemoglobin Evolution, Arvind S. Pillai, Shane A. Chandler, Yang Liu, Anthony V. Signore, Carlos R. Cortez-Romero, Justin L. P. Benesch, Arthur Laganowsky, Jay F. Storz, Georg K. A. Hochberg, Joseph W. Thornton

School of Biological Sciences: Faculty Publications

Most proteins associate into multimeric complexes with specific architectures, which often have functional properties such as cooperative ligand binding or allosteric regulation. No detailed knowledge is available about how any multimer and its functions arose during evolution. Here we use ancestral protein reconstruction and biophysical assays to elucidate the origins of vertebrate hemoglobin, a heterotetramer of paralogous α- and β-subunits that mediates respiratory oxygen transport and exchange by cooperatively binding oxygen with moderate affinity. We show that modern hemoglobin evolved from an ancient monomer and characterize the historical “missing link” through which the modern tetramer evolved—a noncooperative homodimer with high …

Diatom Morphology In Light Of A Changing Climate: A Focus On Aulacoseira Crenulata, Brighid Welchans

Honors Program: Senior Projects (Public)

Fossilized diatoms are arguably the most vital proxy record utilized in paleolimnology. Diatoms are unicellular microalgae that are the basis of countless food webs, are invaluable bioindicators, and generate nearly a quarter of global net primary productivity. Diatoms are affected by a variety of environmental factors but there is relatively little research on how environmental conditions impact diatom valve morphology, and in particular whether there is a correlation between incoming light and diatom pore morphology. This report focuses on the Amazon lowland lake Garzacocha, and analyzes the relationship between light levels and the corresponding size of Aulacoseira crenulata pores. We …

Post‐Dispersal Factors Influence Recruitment Patterns But Do Not Override The Importance Of Seed Limitation In Populations Of A Native Thistle, Tatyana A. Rand, Natalie M. West, F. Leland Russell, Svata M. Louda

School of Biological Sciences: Faculty Publications

Whether plant populations are limited by seed or microsite availability is a long-standing debate. However, since both can be important, increasing emphasis is placed on disentangling their relative importance and how they vary through space and time. Although uncommon, seed addition studies that include multiple levels of seed augmentation, and follow plants through to the adult stage, are critical to achieving this goal. Such data are also vital to understanding when biotic pressures, such as herbivory, influence plant abundance. In this study, we experimentally added seeds of a native thistle, Cirsium canescens, at four augmentation densities to plots at two …

Mechanisms Of Silencing Suppression By A Polerovirus P0 Protein, Natalie Holste, Hernan Garcia-Ruiz

School of Biological Sciences: Presentations

Maize lethal necrosis is an intense viral disease spreading across sub-Saharan Africa. Maize is the staple crop grown in sub-Saharan Africa, but most crops infected with maize lethal necrosis will not survive to harvest. This causes immense economic hardship and starvation within the population. Maize lethal necrosis consists of a combination of two viruses, Maize chlorotic mottle virus (MCMV) and a virus from the genus potyvirus. In a recent study, a Maize yellow dwarf virus-RMV (MYDV-RMV)-like polerovirus, was repeatedly detected in plants with maize lethal necrosis. Poleroviruses have a silencing suppressor, P0 protein, and the mechanism of suppression is poorly …

Distortion Of The Local Magnetic Field Appears To Neither Disrupt Nocturnal Navigation Nor Cue Shelter Recognition In The Amblypygid Paraphrynus Laevifrons, Daniel D. Wiegmann, Patrick Casto, Eileen Hebets, Verner P. Bingman

Eileen Hebets Publications

Many arthropods are known to be sensitive to the geomagnetic field and exploit the field to solve spatial problems. The polarity of the geomagnetic field is used, for instance, as an orientation cue by leafcutter ants as they travel on engineered trails in a rainforest and by Drosophila larvae as they move short distances in search of food. A ubiquitous orientation cue like the geomagnetic field may be especially useful in complex, cluttered environments like rainforests, where the reliability of celestial cues used to navigate in more open environments may be poor. The neotropical amblypygid Paraphrynus laevifrons is a nocturnal …

The Role Of Nestling Acoustic Experience In Song Discrimination In A Sparrow, Emily J. Hudson, Nicole Creanza, Daizaburo Shizuka

School of Biological Sciences: Faculty Publications

Oscine songbirds are an ideal system for investigating how early experience affects vocal behavior. Young songbirds face a challenging task: how to recognize and selectively learn only their own species’ song, often during a time-limited window. Because birds are capable of hearing birdsong very early in life, early exposure to song could plausibly affect recognition of appropriate models; however, this idea conflicts with the traditional view that song learning occurs only after a bird leaves the nest. Thus, it remains unknown whether natural variation in acoustic exposure prior to song learning affects the template for recognition. In a population where …

The Impact Of Nicotine Accumulation Exposure On Lithobates Catebeianus Larvae Mortality, Luke Micek

UCARE: Research Products

Cigarette butts are the most littered item in the world and contain over 4,000 chemicals, including the organic compound nicotine (Slaughter et al. 2011). Billions of cigarette butts are littered each year which may wash into bodies of water, impacting the local wildlife. To determine how introduced chemicals impact the environment, it is important to study its effects on indicator species. Amphibians, such as Lithobates catebeianus, act as indicator species due to their extreme sensitivity to chemical changes in its environment. The purpose of this research project was to obtain data to help determine the impact nicotine accumulation has …

A New Genus And Two New Species Of Unarmed Hymenolepidid Cestodes (Cestoda: Hymenolepididae) From Geomyid Rodents In Mexico And Costa Rica, Scott Lyell Gardner, Altangerel Tsogtsaikhan Dursahinhan, Mariel Campbell, S. Elizabeth Rácz

Scott L. Gardner Publications

Two new cestodes of the family Hymenolepididae are described from two species of rodents of the family Geomyidae collected in Mexico and Costa Rica. One new species of Hymenolepis is described from Cratogeomys planiceps Merriam 1895 from near Toluca, Mexico and another that we allocate to a new genus is described from Heterogeomys heterodus (Peters, 1865) from near Irazú Volcano, Costa Rica. Hymenolepis s. str. includes those Hymenolepididae with an apical organ, with no hooks on suckers or apical organ, and three testes. Hobergia irazuensis n. gen., n. sp. includes a hymenolepidid with an apical organ, unarmed scolex, small …

Prey Selection By Birds Of Prey, Anisha Pokharel

School of Biological Sciences: Dissertations, Theses, and Student Research

Prey selection is key to determine predator prey interaction and understanding the complexity of food web structure. In this thesis, we used two different approaches to understanding prey selection by North American birds of prey. Using a conventional method, in Chapter 1 we compared pellet analysis and trapping data to assess patterns of prey selection of barn owls in western Nebraska. Microtus spp. comprised 55.8% of the prey items in the barn owl’s diet. The proportion of several prey types in the diet were significantly different from the expected proportion based on trapping. This pattern may indicate barn owls actively …

The Relationship Between The Cervical Microbiome And Cervical Cancer Risk In Sub-Saharan Africa, Cameron G. Klein

School of Biological Sciences: Dissertations, Theses, and Student Research

Despite ongoing efforts, sub-Saharan Africa faces a higher cervical cancer burden than anywhere else in the world. Besides HPV infection, definitive factors of cervical cancer are still unclear. Dysbiosis of the cervicovaginal microbiota, particularly involving sexually transmitted infections, is associated with increased cervical cancer risk. Notably, HIV infection, which is prevalent in sub-Saharan Africa, greatly increases risk of cervicovaginal dysbiosis and cervical cancer. To better understand and address cervical cancer in sub-Saharan Africa, a better understanding of the regional cervicovaginal microbiome is required. In this study, I establish the relationship between cervical cancer, HPV, HIV, cervicovaginal infections, and the cervicovaginal …

Before The Pandemic Ends: Making Sure This Never Happens Again, Daniel R. Brooks, Eric P. Hoberg, Walter A. Boeger, Scott Lyell Gardner, Sabrina B. L. Araujo, Katalin Bajer, Sebastian Botero-Cañola, Brian Byrd, Gábor Földvári, Joseph A. Cook, Jonathan L. Dunnum, Altangerel Tsogtsaikhan Dursahinhan, László Zsolt Garamszegi, Dávid Herczeg, Ferenc Jakab, Alicia Juarrero, Gábor Kemenesi, Kornélia Kurucz, Virginia León-Règagnon, Hugo H. Mejía-Madrid, Orsolya Molnár, Richard A. Nisbett, Wolfgang Preiser, Michael Stuart, Eors Szathmary, Valeria Trivellone

Scott L. Gardner Publications

Introduction

On 30 January 2020, the World Health Organization (WHO) declared a Global Health Emergency of international concern attendant to the emergence and spread of SARS-CoV-2, nearly two months after the first reported emergence of human cases in Wuhan, China. In the subsequent two months, global, national and local health personnel and infrastructures have been overwhelmed, leading to suffering and death for infected people, and the threat of socio-economic instability and potential collapse for humanity as a whole. This shows that our current and traditional mode of coping, anchored in responses after the fact, is not capable of dealing with …

Sex And Suicide: The Curious Case Of Toll-Like Receptors, Paulo A. Navarro-Costa, Antoine Molaro, Chandra S. Misra, Colin D. Meiklejohn, Peter J. Ellis

School of Biological Sciences: Faculty Publications

During in vitro fertilisation (IVF), pharmacological activation of the murine X chromosome–encoded receptor proteins Toll-like receptor (TLR) 7 and TLR8 reportedly results in male- biased litters by selectively disrupting the motility of X-bearing sperm cells. Thus—in the context of agonist treatment during IVF—these receptors act as ‘suicidal’ segregation distorters that impair their own transmission to the next generation. Such behaviour would, from an evolutionary perspective, be strongly selected against if present during natural fertilisation. Consequently, TLR7/8 biology in vivo must differ significantly from this in vitro situation to allow these genes to persist in the genome. Here, we use our …

Gaharitrema Droneni N. Gen., N. Sp. (Digenea: Zoogonidae: Lepidophyllinae) From The Pudgy Cuskeel, Spectrunculus Grandis (Ophidiiformes: Ophidiidae), From Deep Waters Off Oregon, With Updates Keys To Zoogonid Subfamilies And Genera, Charles K. Blend, Gábor R. Rácz, Scott Gardner

Scott L. Gardner Publications

Gaharitrema droneni n. gen., n. sp. (Digenea: Zoogonidae: Lepidophyllinae) is described from the intestine of the pudgy cuskeel, Spectrunculus grandis (Gu¨ nther, 1877) (Ophidiiformes: Ophidiidae), collected at 2,800 m depth from the northeastern Pacific Ocean off Oregon. The new genus is distinguished from Brachyenteron Manter, 1934 and Steganoderma Stafford, 1904, the 2 closest lepidophylline genera, and from 4 other zoogonid genera erected since 2007, the last major revision of the family, by a combination of diagnostic features including a pyriform or spindle-shaped body, smooth testes and ovary, narrow ceca that reach with the vitellarium into the hindbody, an unspecialized ventral …

Genetic Diversity Of Potassium Ion Channel Proteins Encoded By Chloroviruses That Infect Chlorella Heliozoae, Carter Murry

Honors Program: Senior Projects (Public)

Chloroviruses are large, plaque-forming, double-stranded DNA viruses that infect chlorella-like green algae that live in a symbiotic relationship with protists. Chloroviruses have a genome from 290 to 370 kb, and they encode as many as 400 proteins. One interesting feature of chloroviruses is that they encode a potassium ion (K⁺) channel protein named Kcv. K⁺ channels are essential proteins for life. They cross the membrane of the cell to quickly and selectively allow K⁺ in or out of the cell. This helps regulate the electrical charge of a cell which in turn helps control electrical signaling …

Tolerance Of Novel Toxins Through Generalized Mechanisms: Simulating Gradual Host Shifts Of Butterflieskristin, Kristin L. Sikkink, Reilly Hostager, Megan E. Kobiela, Nathan Fremling, Katherine Johnston, Amod Zambre, Emilie C. Snell-Rood

School of Biological Sciences: Faculty Publications

Organisms encounter a wide range of toxic compounds in their environments, from chemicals that serve anticonsumption or anticompetition functions to pollutants and pesticides. Although we understand many detoxification mechanisms that allow organisms to consume toxins typical of their diet, we know little about why organisms vary in their ability to tolerate entirely novel toxins. We tested whether variation in generalized stress responses, such as antioxidant pathways, may underlie variation in reactions to novel toxins and, if so, their associated costs. We used an artificial diet to present cabbage white butterfly caterpillars (Pieris rapae) with plant material containing toxins not experienced …

Range Extension For Dekay’S Brownsnake (Storeria Dekayi) In South-Central Nebraska, Macy K. Cool, Keith Geluso

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Dekay’s Brownsnake (Storeria dekayi) generally occurs in southeastern parts of the state, where the species was known from 16 counties. Herein, we update the distribution of S. dekayi in the state and briefly comment on habitat and abundance from observations in September and October 2018. We documented 7 new county records that extend its distribution in south-central Nebraska. We observed that S. dekayi does not only reside in mesic wooded habitats in Nebraska but also occupies open environments, including areas with upland grasslands and row-crop agriculture. Dekay’s Brownsnake currently is listed as a species of concern …