Biology Commons^™

Lichens Of Pine Hill, A Peridotite Outcrop In Eastern North America, Tanner B. Harris, Fred C. Olday, Nishanta Rajakaruna

Biological Sciences

Despite a large body of work on the serpentine-substrate effect on vascular plants, little work has been undertaken to describe lichen communities growing on serpentine soils derived from peridotite and other ultramafic rocks. Most such work has been conducted in Europe and western North America. Only one study to date has examined the lichen flora of an ultramafic outcrop in eastern North America. The current paper examines the lichen flora of a peridotite outcrop from Deer Isle, Hancock County, Maine, U.S.A. The lichen flora is presented along with relevant ecological and geochemical data. Sixty-three species were found, comprising 35 genera. …

Bioluminescence In A Complex Coastal Environment: 2. Prediction Of Bioluminescent Source Depth From Spectral Water-Leaving Radiance, Matthew J. Oliver, Mark A. Moline, Curtis D. Mobley, Lydia Sundman, Oscar M.E. Schofield

Biological Sciences

Many bioluminescence observations are made from the ocean's surface. However, the depth of the bioluminescent source is difficult to estimate on the basis of surface observations alone, given the variable light attenuation of unknown concentrations of water column constituents such as phytoplankton, colored dissolved organic matter, and detritus. Part 1 of this paper showed that bioluminescent water-leaving radiance signals are detectable, even in extremely turbid and dynamic coastal waters. Here, in part 2 of this paper, we analyze the water-leaving radiance patterns of bioluminescence modeled by HydroLight 4.2 to determine if the depth of the bioluminescent source can be estimated …

Temperature Effects On Metabolic Rate Of Juvenile Pacific Bluefin Tuna Thunnus Orientalis, Jason M. Blank, Jeffery M. Morrissette, Charles J. Farwell, Mathew Price, Robert J. Schallert, Barbara A. Block

Biological Sciences

Pacific bluefin tuna inhabit a wide range of thermal environments across the Pacific ocean. To examine how metabolism varies across this thermal range, we studied the effect of ambient water temperature on metabolic rate of juvenile Pacific bluefin tuna, Thunnus thynnus, swimming in a swim tunnel. Rate of oxygen consumption (M_O2) was measured at ambient temperatures of 8–25°C and swimming speeds of 0.75–1.75 body lengths (BL) s^–1. Pacific bluefin swimming at 1 BL s^–1 per second exhibited a U-shaped curve of metabolic rate vs ambient temperature, with a thermal minimum zone between …

Fuzzy Data Sets, William D. Stansfield

Biological Sciences

No abstract provided.

Genetic Evidence For The Persistence Of The Critically Endangered Sierra Nevada Red Fox In California, John D. Perrine, John P. Pollinger, Benjamin N. Sacks, Reginald H. Barrett, Robert K. Wayne

Biological Sciences

California is home to both the native state-threatened Sierra Nevada red fox (Vulpes vulpes necator), which historically inhabited high elevations of the Sierra Nevada and Cascade mountains, and to multiple low-elevation red fox populations thought to be of exotic origin. During the past few decades the lowland populations have dramatically expanded their distribution, and possibly moved into the historic range of the native high-elevation fox. To determine whether the native red fox persists in its historic range in California, we compared mitochondrial cytochrome-b haplotypes of the only currently-known high-elevation population (n = 9 individuals) to samples …

Protective Capactiy Of Mangroves During Tropical Storms: A Case Study From 'Wilma' And 'Gamma' In Belize, Elise F. Granek, Benjamin I. Ruttenberg

Biological Sciences

Globally threatened mangrove forest habitat is often considered an important buffer protecting coastlines from wave and storm impacts and coastal erosion. However, there is little empirical data quantifying the protective effects of mangroves during storms, primarily because of the difficulty of predicting where and when a storm will intersect the shoreline, to facilitate data collection before and after storm events. In 2005, opportunistic results from an ongoing study quantifying differences between intact and cleared mangrove areas on Turneffe Atoll, Belize, provided such pre- and post-storm data from tropical storms ‘Wilma’ (later a Category 5 Hurricane) and ‘Gamma’. We compared differences …

Recombination And Positive Selection Contribute To Evolution Of Listeria Monocytogenes Inla, R. H. Orsi, D. R. Ripoll, M. Yeung, K. K. Nightingale, M. Wiedmann

Biological Sciences

The surface molecule InlA interacts with E-cadherin to promote invasion of Listeria monocytogenes into selected host cells. DNA sequencing of inlA for 40 L. monocytogenes isolates revealed 107 synonymous and 45 nonsynonymous substitutions. A frameshift mutation in a homopolymeric tract encoding part of the InlA signal peptide was identified in three lineage II isolates, which also showed reduced ability to invade human intestinal epithelial cells. Phylogenies showed clear separation of inlA sequences into lineages I and II. Thirteen inlA recombination events, predominantly involving lineage II strains as recipients (12 events), were detected and a number of amino acid residues were …

The Relationship Between Disperal Ability And Geographic Range Size, Sarah E. Lester, Benjamin I. Ruttenberg, Steven D. Gaines, Brian P. Kinlan

Biological Sciences

There are a variety of proposed evolutionary and ecological explanations for why some species have more extensive geographical ranges than others. One of the most common explanations is variation in species’ dispersal ability. However, the purported relationship between dispersal distance and range size has been subjected to few theoretical investigations, and empirical tests reach conflicting conclusions. We attempt to reconcile the equivocal results of previous studies by reviewing and synthesizing quantitative dispersal data, examining the relationship between average dispersal ability and range size for different spatial scales, regions and taxonomic groups. We use extensive data from marine taxa whose average …

The Phd Degree And Biblical Fundamentalism, William D. Stansfield

Biological Sciences

No abstract provided.

Biofouling Likely Serves As A Major Mode Of Dispersal For The Polychaete Tubeworm Hydroides Elegans As Inferred From Microsatellite Loci, J. B. Pettengill, D. E. Wendt, M. D. Schug, M. G. Hadfield

Biological Sciences

The polychaete tubeworm Hydroides elegans (Haswell) is a biofouling species with relatively limited larval dispersal. Four highly polymorphic microsatellite loci were used to make inferences about the migration and global population structure of 137 individuals from seven sub-populations located in the Atlantic, Pacific, and Indian Oceans and in the Mediterranean Sea. The results of the genetic analyses suggest minimal population sub-structure (F_st = 0.09). Estimates of pairwise F_st and migration rates using the coalescent-based method of MIGRATE suggest that there is little genetic differentiation between certain populations. Variation in relatedness among pairs of populations is consistent with a …

Neural Defects And Cardiac Arrhythmia In Fish Larvae Following Embryonic Exposure To 2,2',4,4'-Tetrabromodiphenyl Ether (Pbde 47), Sean C. Lema, Irvin R. Schultz, Nathaniel L. Scholz, John P. Incardona, Penny Swanson

Biological Sciences

Polybrominated diphenyl ethers (PBDEs) are added to plastics, polyurethane foam, and textiles as a flame retardant. While PBDEs play a key role in reducing loss of human life and property from fires, these flame retardants have become pervasive organic contaminants in the environment and in the tissues of fish, birds, marine mammals, and humans. Levels of PBDEs in wildlife and humans continue to rise, raising concerns about potential ecological and health risks associated with exposure to these chemicals. Nevertheless, there is little currently known about the toxicological effects of PBDE exposure. Here, we examined the developmental toxicity of the PBDE …

Human Sex Ratios And Sex Distribution In Sibships Of Size 2, William D. Stansfield, Matthew A. Carlton

Biological Sciences

We previously analyzed data from the U.S. National Health Interview Survey (NHIS, 1998 to 2002) on families with two biological children (10 years of age and younger) and found that the distribution of families with two boys, two girls, and one boy + one girl did not statistically conform to a binomial distribution regardless of the boy/girl sex ratio used. Using the best estimate of the sex ratio from the data, we found that there were significantly more families with opposite-sex siblings than families with same-sex siblings. No biological mechanism could explain these results at the time. In the present …

Counterproductive Mix Of Science And Theology: Review Of Astronomy And The Bible - Questions And Answers By Donald B. Deyoung, William D. Stansfield

Biological Sciences

No abstract provided.

Specimens Of The Billfish Xiphiorhynchus Van Beneden, 1871, From The Yazoo Clay Formation (Late Eocene), Louisiana, Harry L. Fierstine, Gary L. Stringer

Biological Sciences

No abstract provided.

Genome Size Evolution In Relation To Leaf Strategy And Metabolic Rates Revisited, Jeremy M. Beaulieu, Ilia J. Leitch, Charles A. Knight

Biological Sciences

• Background and AimsIt has been proposed that having too much DNA may carry physiological consequences for plants. The strong correlation between DNA content, cell size and cell division rate could lead to predictable morphological variation in plants, including a negative relationship with leaf mass per unit area (LMA). In addition, the possible increased demand for resources in species with high DNA content may have downstream effects on maximal metabolic efficiency, including decreased metabolic rates.

• MethodsTests were made for genome size-dependent variation in LMA and metabolic rates (mass-based photosynthetic rate and dark respiration rate) using our own …

Environmental And Genetic Influences On Mating Strategies Along A Replicated Food Availability Gradient In Guppies (Poecilia Reticulata), Gita R. Kolluru, Gregory F. Grether, Heidy Contreras

Biological Sciences

Food availability is expected to influence the relative cost of different mating tactics, but little attention has been paid to this potential source of adaptive geographic variation in behavior. Associations between the frequency of different mating tactics and resource availability could arise because tactic use responds directly to food intake (phenotypic plasticity), because populations exposed to different average levels of food availability have diverged genetically in tactic use, or both. Different populations of guppies (Poecilia reticulata) in Trinidad experience different average levels of food availability. We combined field observations with laboratory “common garden” and diet experiments to examine how this …

Influence Of Swimming Speed On Metabolic Rates Of Juvenile Pacific Bluefin Tuna And Yellowfin Tuna, Jason M. Blank, Charles J. Farwell, Jeffery M. Morrissette, Robert J. Schallert, Barbara A. Block

Biological Sciences

Bluefin tuna are endothermic and have higher temperatures, heart rates, and cardiac outputs than tropical tuna. We hypothesized that the increased cardiovascular capacity to deliver oxygen in bluefin may be associated with the evolution of higher metabolic rates. This study measured the oxygen consumption of juvenile Pacific bluefin Thunnus orientalis and yellowfin tuna Thunnus albacares swimming in a swim-tunnel respirometer at 20°C. Oxygen consumption ( Mo₂) of bluefin (7.1–9.4 kg) ranged from 235 ± 38 mg kg^-1 h^-1 at 0.85 body length (BL) s^-1 to 498 ± 55 mg kg^-1 h^-1 at 1.80 …

Availability Of Dissolved Organic Matter Offsets Metabolic Costs Of A Protracted Larval Period For Bugula Neritina (Bryozoa), Collin H. Johnson, Dean E. Wendt

Biological Sciences

For nearly a century researchers have investigated the uptake and utilization of dissolved organic matter (DOM) by marine invertebrates, but its contribution to their growth, reproduction, and survival remains unclear. Here, the benefit of DOM uptake was assessed for the marine bryozoan Bugula neritina (Linnaeus 1758) through performance comparisons of individuals in the presence and absence of DOM. The experiments were performed using B. neritina collected from floating docks in Beaufort, NC, USA from July to September 2004. Seawater was subjected to ultraviolet irradiation to reduce naturally occurring DOM, and then enriched with either 1 μM of palmitic acid or …

A Novel Lux Operon In The Cryptically Bioluminescent Fish Pathogen Vibrio Salmonicida Is Associated With Virulence, Eric J. Nelson, Hege S. Tunsjø, Pat M. Fidopiastis, Henning Sørum, Edward G. Ruby

Biological Sciences

The cold-water-fish pathogen Vibrio salmonicida expresses a functional bacterial luciferase but produces insufficient levels of its aliphatic-aldehyde substrate to be detectably luminous in culture. Our goals were to (i) better explain this cryptic bioluminescence phenotype through molecular characterization of the lux operon and (ii) test whether the bioluminescence gene cluster is associated with virulence. Cloning and sequencing of the V. salmonicida lux operon revealed that homologs of all of the genes required for luminescence are present: luxAB (luciferase) and luxCDE (aliphatic-aldehyde synthesis). The arrangement and sequence of these structural lux genes are conserved compared to those in related species of …

Discriminant Function Analysis In Marine Ecology: Some Oversights And Their Solutions, J. Wilson White, Benjamin I. Ruttenberg

Biological Sciences

Marine ecologists commonly use discriminant function analysis (DFA) to evaluate the similarity of distinct populations and to classify individuals of unknown origin to known populations. However, investigators using DFA must account for (1) the possibility of correct classification due to chance alone, and (2) the influence of prior probabilities of group membership on classification results. A search of the recent otolith chemistry literature showed that these two concerns are sometimes ignored, so we used simulated data sets to explore the potential pitfalls of such oversights. We found that when estimating reclassification success for a training data set, small sample sizes …

Arbor Day Confusion, William D. Stansfield

Biological Sciences

No abstract provided.

Correlated Evolution Of Genome Size And Seed Mass, Jeremy M. Beaulieu, Angela T. Moles, Ilia J. Leitch, Michael D. Bennett, John B. Dickie, Charles A. Knight

Biological Sciences

• Previous investigators have identified strong positive relationships between genome size and seed mass within species, and across species from the same genus and family. • Here, we make the first broad-scale quantification of this relationship, using data for 1222 species, from 139 families and 48 orders. We analyzed the relationship between genome size and seed mass using a statistical framework that included four different tests. • A quadratic relationship between genome size and seed mass appeared to be driven by the large genome/seed mass gymnosperms and the many small genome size/large seed mass angiosperms. Very small seeds were never …

Proximate Developmental Mediators Of Sexual Dimorphism In Size: Case Studies From Squamate Reptiles, Henry B. John‐Alder, Robert M. Cox, Emily N. Taylor

Biological Sciences

Sexual dimorphism in size (sexual size dimorphism; SSD) is nearly ubiquitous, but the relative importance of genetic versus environmental control of SSD is not known for most species. We investigated proximate determinants of SSD in several species of squamate reptiles, including three species of Sceloporus lizards and the diamond‐backed rattlesnake (Crotalus atrox). In natural populations of these species, SSD is caused by sexual differences in age‐specific growth. Males and females, however, may often share similar potentials for growth: growth is strongly responsive to the availability of food, and sexual differences in growth can be greatly suppressed or completely …

The Role Of Local And Regional Processes In Structuring Larval Dragonfly Distributions Across Habitat Gradients, S J. Mccauley

Biological Sciences

Despite the importance of community-structuring processes operating at both local and regional scales, there is relatively little work examining both forces within a single system. I used a combination of observational and experimental approaches to examine the processes structuring larval dragonfly distributions in lentic habitats that encompass a gradient of both permanence and top predator type. I compared the relative vulnerability of species to predators from different portions of this gradient to assess the role of predation as a local force structuring communities. I also assessed the role of regional processes on species’ distributions by examining species’ propensity to disperse …

Nontarget Effects Of The Mosquito Adulticide Pyrethrin Applied Aerially During A West Nile Virus Outbreak In An Urban California Environment, Walter M. Boyce, Sharon P. Lawler, Jennifer M. Schultz, Shannon J. Mccauley, Lynn S. Kimsey, Michael K. Niemela, Carrie F. Nielsen, William K. Reisen

Biological Sciences

In August 2006, a pyrethrin insecticide synergized with piperonyl butoxide (EverGreen Crop Protection EC 60-6, McLaughlin Gormley King Company, Golden Valley, MN) was sprayed in ultralow volumes over the city of Davis, CA, by the Sacramento-Yolo Mosquito and Vector Control District to control mosquitoes transmitting West Nile virus. Concurrently, we evaluated the impact of the insecticide on nontarget arthropods by 1) comparing mortality of treatment and control groups of sentinel arthropods, and 2) measuring the diversity and abundance of dead arthropods found on treatment and control tarps placed on the ground. We found no effect of spraying on nontarget sentinel …

Compartmentalization Of The Broad-Range Phospholipase C Activity To The Spreading Vacuole Is Critical For Listeria Monocytogenes Virulence, P.S. Marie Yeung, Yoojin Na, Amanda J. Kreuder, Helene Marquis

Biological Sciences

Listeria monocytogenes is a bacterial pathogen that multipliesin the cytosol of host cells and spreads directly from cellto cell by using an actin-based mechanism of motility. The broad-rangephospholipase C (PC-PLC) of L. monocytogenes contributes tobacterial escape from vacuoles formed upon cell-to-cell spread.PC-PLC is made as an inactive proenzyme whose activation requirescleavage of an N-terminal propeptide. During infection, PC-PLCis activated specifically in acidified vacuoles. To assess theimportance of compartmentalizing PC-PLC activity during infection,we created a mutant that makes constitutively active PC-PLC(the plcBpro mutant). Results from intracellular growth andcell-to-cell spread assays showed that the plcBpro mutant wassensitive to gentamicin, suggesting …

Evaluation Of A Tissue Culture-Based Approach For Differentiating Between Virulent And Avirulent Vibrio Parahaemolyticus Strains Based On Cytotoxicity, P.S. Marie Yeung, Martin Wiedmann, Kathryn J. Boor

Biological Sciences

The ability of only a subset of Vibrio parahaemolyticus strains to cause human infection underscores the need for an analytical method that can effectively differentiate between pathogenic strains and those that do not cause disease. We tested the feasibility of a tissue culture-based assay to determine whether clinical isolates could be differentiated from nonclinical isolates based on relative isolate cytopathogenicity. To screen for cytotoxic capability, we measured relative extracellular lactate dehydrogenase as an indicator of host cell damage in five different mammalian cell lines in the presence of V. parahaemolyticus. Isolates originating from clinical sources exhibited 15.5 to 59.3% …

The Long And Winding Road: Influences Of Intracellular Metabolite Diffusion On Cellular Organization And Metabolism In Skeletal Muscle, Stephen T. Kinsey, Kristin M. Hardy, Bruce R. Locke

Biological Sciences

A fundamental principle of physiology is that cells are small in order to minimize diffusion distances for O₂ and intracellular metabolites. In skeletal muscle, it has long been recognized that aerobic fibers that are used for steady state locomotion tend to be smaller than anaerobic fibers that are used for burst movements. This tendency reflects the interaction between diffusion distances and aerobic ATP turnover rates, since maximal intracellular diffusion distances are ultimately limited by fiber size. The effect of diffusion distance on O₂ flux in muscle has been the subject of quantitative analyses for a century, but the …

Consequences Of A Genetic Bottleneck In California Condors: A Mitochondrial Dna Perspective, Mary S. Adams, Francis X. Villablanca

Biological Sciences

The California Condor (Gymnogyps californianus) has recently survived a severe population bottleneck. The entire population was reduced to 27 individuals in 1982. The number of genetic founders was even smaller. We obtained 482 base pairs of DNA sequence from the mitochondrial control region (CR) of all founder individuals that potentially represented unique maternal haplotypes. Four unique haplotypes were present in the genetic founders. One of these haplotypes is unique to Topatopa, a male brought into captivity in 1967, whose haplotype will not persist in the future population. Haplotype diversity (h) was reduced by 25% between the founder population …