Life Sciences Commons^™

The Complexity Of Amphibian Population Declines: Understanding The Role Of Cofactors In Driving Amphibian Losses, Andrew Blaustein, Barbara Han, Rick Relyea, Pieter Johnson, Julia Buck, Stephanie Gervasi, Lee Kats

Lee Kats

Population losses and extinctions of species are occurring at unprecedented rates, as exemplified by declines and extinctions of amphibians worldwide. However, studies of amphibian population declines generally do not address the complexity of the phenomenon or its implications for ecological communities, focusing instead on single factors affecting particular amphibian species. We argue that the causes for amphibian population declines are complex; may differ among species, populations, and life stages within a population; and are context dependent with multiple stressors interacting to drive declines. Because amphibians are key components of communities, we emphasize the importance of investigating amphibian declines at the …

Exploring Demographic, Physical, And Historical Explanations For The Genetic Structure Of Two Lineages Of Greater Antillean Bats, Robert A. Muscarella, Kevin L. Murray, Derek Ortt, Amy L. Russell, Theodore H. Fleming

Amy L. Russell

Description Of The Tadpoles Of Hypsiboas Aguilari And H. Melanopleura Aguilari And H. Melanopleura (Anura: Hylidae: Hypsiboas Pulchellus Group), Edgar Lehr, Julian Faivovich, Karl-Heinz Jungfer

Edgar Lehr

We describe the tadpoles of Hypsiboas melanopleura and H. aguilari and compare them with the tadpoles of other species in the Hypsiboas pulchellus group. The description of the tadpole of H. aguilari is based on an individual at Gosner Stage 29 and that of H. melanopleura on an individual at Gosner Stage 28. Both tadpoles have a labial tooth row formula of 2(2)/4(1). At Stage 35, the tadpole of H. aguilari had a total length of 52.2 mm, at Stage 37, the tadpole of H. melanopleura had a total length of 60.7 mm. In life, the tadpole of H. aguilari …

Biodepollution Of Wastewater Containing Phenolic Compounds From Leather Industry By Plant Peroxidases, Mamounata Diao, Nafissetou Ouedraogo, Lamine Baba-Moussa, Paul W. Savadogo, Georges N'Guessan Amani, Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

This study deals with the use of peroxidases (POXs) from Allium sativum, Ipomoea batatas, Raphanus sativus and Sorghum bicolor to catalyze the degradation of free phenolic compounds as well as phenolic compounds contained in wastewater from leather industry. Secretory plant POXs were able to catalyze the oxidation of gallic acid, ferulic acid, 4-hydroxybenzoic acid, pyrogallol and 1,4-tyrosol prepared in ethanol 2% (v:v). Efficiency of peroxidase catalysis depends strongly on the chemical nature of phenolic substrates and on the botanical source of the enzymes. It appeared that POX from Raphanus sativus had the highest efficiency. Results show that POXs can also …

Reduced Mhc And Neutral Variation In The Galápagos Hawk, An Island Endemic, Jennifer L. Bollmer, Joshua M. Hull, Holly B. Ernest, José H. Sarasola, Patricia G. Parker

Patricia Parker

Using Google Earth To Teach The Magnitude Of Deep Time, Joel D. Parker

Joel D Parker

Most timeline analogies of geologic and evolutionary time are fundamentally flawed. They trade off the problem of grasping very long times for the problem of grasping very short distances. The result is an understanding of relative time with little comprehension of absolute time. Earlier work has shown that the distances most easily understood by teachers and students are those most people can experience directly. Thus most timeline analogies are flawed by either overcompressing an experienceable time or relying on an unexperienceable distance. Under the constraint of experienceability, the best timeline to distance scale must be at least 75 miles and …

Fine-Scale Distribution Patterns Of Synechococcus Ecological Diversity In The Microbial Mat Of Mushroom Spring, Yellowstone National Park, Eric Becraft, Frederick Cohan, Michael Kuhl, Sheila Jensen, David Ward

Frederick M. Cohan

No abstract provided.

Buried Clay Pot Irrigation, David A. Bainbridge

David A Bainbridge

Buried clay pot irrigation was first described in Chinese texts from more than 2000 years ago. It uses a porous clay pot to provide demand responsive irrigation. Efficiency is often 3-10 times conventional surface irrigation.

Passive Solar Design, David A. Bainbridge

David A Bainbridge

Passive solar architecture can provide heating, cooling, ventilation and daylighting by using the sun and microclimate resources. Building energy consumption can be cut 80-90% at no increase in building cost by using integrated design principles.

Geologic Constraints On Rain-Fed Qocha Reservoir Agricultural Infrastructure,Northern Lake Titicaca Basin, Peru, Nathan Craig, Mark Aldenderfer, Catherine Rigsby, Paul Baker, Luis A. Flores

Luis FLORES

This paper reports new data on qocha ponds from the Rio PucaraeAzángaro interfluvial zone, northern Lake Titicaca Basin, Peru. Qocha are a little known form of Andean agriculture that developed around 800e500 B.C. and remain in use today. Prior estimates suggested that in the study area, there were more than 25,000 qocha. While most Andean sunken beds are excavated to reach groundwater, qocha are rainfed ponds. How these rain-fed ponds functioned has been an open question, but one that is answered in part by research presented in this paper. We suggest that a thick impermeable stratum of clay that was …

Population And Politics Of A Plover, Fritz Knopf, Victoria Dreitz

Victoria Dreitz

No abstract provided.

The Survival Of The Conformist: Social Pressure And Renewable Resource Management, Alessandro Tavoni

Alessandro Tavoni

This paper examines the role of other-regarding behavior as a mechanism for the establishment and maintenance of cooperation in resource use under variable social and environmental conditions. By coupling resource stock dynamics with social dynamics concerning compliance to a social norm prescribing non-excessive resource extraction in a common 10 pool resource, we show that when reputational considerations matter and a sufficient level of social stigma affects the violators of a norm, sustainable outcomes are achieved. We find large parameter regions where norm-observing and norm-violating types coexist, and analyze to what extent such coexistence depends on the environment.

Detection And Characterization Of A Distinct Bornavirus Lineage From Healthy Canada Geese (Branta Canadensis), John A. Baroch

John A Baroch

Avian bornaviruses (ABV), identified in 2008, infect captive parrots and macaws worldwide. The natural reservoirs of these viruses are unknown. Reverse transcription-PCR (RT-PCR) was used to screen oropha- ryngeal/cloacal swab and brain samples from wild Canada geese (Branta canadensis) for ABV. Approximately 2.9% of swab samples were positive for bornavirus sequences. Fifty-two percent of brain samples from 2 urban flocks also tested positive, and brain isolates were cultured in duck embryo fibroblasts. Phylogenetic analyses placed goose isolates in an independent cluster, and more notably, important regulatory sequences present in Borna disease virus but lacking in psittacine ABVs were present in …

Phenology Of Stable Fly (Diptera: Muscidae) Larvae In Round Bale Hay Feeding Sites In Eastern Nebraska., David B. Taylor, Dennis R. Berkebile

David B Taylor

The temporal and spatial patterns of adult stable fly, Stomoxys calcitrans (L.), emergence from six sites where large round baled hay had been provided to pasture cattle as winter feed were studied using emergence traps. The substrate at these sites, consisting of waste hay mixed with bovine manure and urine, provided an excellent developmental habitat for immature stable flies. Stable flies were the most frequently collected fly emerging from these sites with a yearly average of 1,581 emerging per square meter. Stable fly emergence from these sites began in early May (235 annual accumulated Day-Degree 10° C [DD10]), peaked in …

Ameliorating The Effects Of The Digenetic Trematode, Bolbophorus Damnificus On The Channel Catfish Industry, Lester Khoo, David J. Wise, Linda M. Pote, Andrew J. Mitchell, Todd S. Byars, Marlena C. Yost, Cynthia M. Doffitt, Brian S. Dorr

Brian S Dorr

No abstract provided.

Decadal-Scale Changes In Southern California Sciaenids Under Different Levels Of Harvesting Pressure, Eric F. Miller, Daniel J. Pondella Ii, D Shane Beck, Kevin T. Herbinson

Daniel Pondella

A unique 38-year time-series of power-plant entrapment data collected across ∼170 km of the southern California coastline was examined to describe the decadal-scale trends in common Southern California Bight sciaenid abundance in relation to oceanographic conditions. Adult catches for five of seven species declined at differing rates and severity. Declines of up to 94% were detected in historically common species such as Genyonemus lineatus, whereas historically less abundant species have increased dramatically, e.g. Umbrina roncador (2626%). Over time, the entrapped community became increasingly influenced by species with more southerly distributions, indicated by a significant decline in the average latitudinal midpoint …

Population Growth Of Mexican Free-Tailed Bats (Tadarida Braziliensis Mexicana) Predates Human Agricultural Activity, A. L. Russell, M. P. Cox, V. A. Brown, Gary F. Mccracken

Gary F. McCracken

Background

Human activities, such as agriculture, hunting, and habitat modification, exert a significant effect on native species. Although many species have suffered population declines, increased population fragmentation, or even extinction in connection with these human impacts, others seem to have benefitted from human modification of their habitat. Here we examine whether population growth in an insectivorous bat (Tadarida brasiliensis mexicana) can be attributed to the widespread expansion of agriculture in North America following European settlement. Colonies of T. b. mexicana are extremely large (~106 individuals) and, in the modern era, major agricultural insect pests form an important component of their …

The Composite Insect Trap: An Innovative Combination Trap For Biologically Diverse Sampling, Laura Russo, Rachel Stehouwer, J. Heberling, Katriona Shea

Mason Heberling

No abstract provided.

Pollen Viability Across A Landscape: Geographic Variation In The Cost Of Male-Fertility Restoration In Gynodioecious Lobelia Siphilitica, Maia F. Bailey, Andrea Case, Christina Caruso

Maia F. Bailey

No abstract provided.

Development Of Campsite Monitoring Protocols In Kenai Fjords, F. Klasner, Christopher Monz, J. Cusick

Christopher Monz

No abstract provided.

The Consequences Of Backcountry Surface Disposal Of Human Waste In An Alpine, Temperate Forest And Arid Environment, M. D. Ells, Christopher Monz

Christopher Monz

No abstract provided.

Pathways For Positive Cattle-Wildlife Interactions In Semi-Arid Rangelands, Kari E. Veblen

Kari E. Veblen

Livestock-wildlife interactions in rangelands are often viewed in terms of competition, but livestock and native ungulates can also benefit each other through long- term modifications of rangeland habitats. Here we synthesize research on rangelands in central Laikipia focusing on two types of cattle-wildlife interactions that have implications for their long-term coexistence. The first interaction occurs via redistribution of soil nutrients within the ecosystem, which is a consequence of the use of bomas (temporary corrals) to manage livestock. Our studies on two different soil types show that rotational boma management creates hectare-scale patches in the landscape that are enriched in soil …

Intracellular Invasion Of Green Algae In A Salamander Host, Ryan Kerney, Eunsoo Kim, Roger Hangater, Aaron Heiss, Cory Bishop, Brian Hall

Ryan Kerney

The association between embryos of the spotted salamander (Ambystoma maculatum) and green algae (“Oophila amblystomatis” Lamber ex Printz) has been considered an ectosymbiotic mutualism. We show here, however, that this symbiosis is more intimate than previously reported. A combination of imaging and algal 18S rDNA amplification reveals algal invasion of embryonic salamander tissues and cells during development. Algal cells are detectable from embryonic and larval Stages 26–44 through chlorophyll autofluorescence and algal 18S rDNA amplification. Algal cell ultrastructure indicates both degradation and putative encystment during the process of tissue and cellular invasion. Fewer algal cells were detected in later-stage larvae …

Symbioses Between Salamander Embryos And Green Algae, Ryan Kerney

Ryan Kerney

The symbiosis between Ambystoma maculatum (spotted salamander) embryos and green algae was initially described over 120 years ago. Algae populate the egg capsules that surround individual A. maculatum embryos, giving the intracapsular fluid a characteristic green hue. Early work established this symbiosis to be a mutualism, while subsequent studies sought to identify the material benefits of this association to both symbiont and host. These studies have shown that salamander embryos benefit from increased oxygen concentrations provided by their symbiotic algae. The algae, in turn, may benefit from ammonia excreted by the embryos. All of these early studies considered the associ- …

Molecular Anatomy Of The Developing Limb In The Coqu ́I Frog, Eleutherodactylus Coqui, Joshua Gross, Ryan Kerney, James Hanken, Clifford Tabin

Ryan Kerney

The vertebrate limb demonstrates remark- able similarity in basic organization across phylogenetically disparate groups. To gain further insight into how this mor- phological similarity is maintained in different developmental contexts, we explored the molecular anatomy of size-reduced embryos of the Puerto Rican coqu ́ı frog, Eleutherodactylus coqui. This animal demonstrates direct development, a life- history strategy marked by rapid progression from egg to adult and absence of a free-living, aquatic larva. Nonethe- less, coqu ́ı exhibits a basal anuran limb structure, with four toes on the forelimb and five toes on the hind limb. We in- vestigated the extent to …

Plant-Animal Interactions, W. Abrahamson, T. Taylor

Warren G. Abrahamson, II

No abstract provided.

Levels Of Biological Organization And The Origin Of Novelty, Brian Hall, Ryan Kerney

Ryan Kerney

The concept of novelty in evolutionary biology pertains to multiple tiers of biological organization from behavioral and morphological changes to changes at the molecular level. Identifying novel features requires assessments of similarity (homology and homoplasy) of relationships (phylogenetic history) and of shared developmental and genetic pathways or networks. After a brief discussion of how novelty is used in recent literature, we discuss whether the evolutionary approach to homology and homoplasy initially formulated by Lankester in the 19th century informs our understanding of novelty today. We then discuss six examples of morphological features described in the recent literature as novelties, and …

Calibrating Divergence Times On Species Tree Versus Gene Trees: Implications For Speciation History Of Aphelocoma Jays, John Mccormack, Joseph Heled, Kathleen Delaney, A. Peterson, L. Knowles

John E. McCormack

Estimates of the timing of divergence are central to testing the underlying causes of speciation. Relaxed molecular clocks and fossil calibration have improved these estimates; however, these advances are implemented in the context of gene trees, which can overestimate divergence times. Here we couple recent innovations for dating speciation events with the analytical power of species trees, where multilocus data are considered in a coalescent context. Divergence times are estimated in the bird genus Aphelocoma to test whether speciation in these jays coincided with mountain uplift or glacial cycles. Gene trees and species trees show general agreement that diversification began …

Embryonic Staging Table For A Direct- Developing Salamander, Plethodon Cinereus (Plethodontidae), Ryan Kerney

Ryan Kerney

This work presents a refined staging table for the direct-developing red-backed salamander Plethodon cinereus, which is based on the incom- plete staging system of James Norman Dent (J Morphol 1942; 71:577– 601). This common species from eastern North America is a member of the species-rich lungless salamander family Plethodontidae. The stag- ing table presented here covers several stages omitted by Dent and reveals novel developmental features of P. cinereus embryos. These include putative Leydig cells and open gill clefts, which are found in lar- vae of metamorphosing species but were previously reported as absent in direct-developing Plethodon. Other features found …

Adaptation As Process: The Future Of Darwinism And The Legacy Of Theodosius Dobzhansky, David Depew

David J Depew

Conceptions of adaptation have varied in the history of genetic Darwinism depending on whether what is taken to be focal is the process of adaptation, adapted states of populations, or discrete adaptations in individual organisms. I argue that Theodosius Dobzhansky’s view of adaptation as a dynamical process contrasts with so-called “adaptationist” views of natural selection figured as “design-without-a-designer” of relatively discrete, enumerable adaptations. Correlated with these respectively process and product oriented approaches to adaptive natural selection are divergent pictures of organisms themselves as developmental wholes or as “bundles” of adaptations. While even process versions of genetical Darwinism are insufficiently sensitive …