Biology Commons^™

Egg Removal By Brown-Headed Cowbirds: A Field Test Of The Host Incubation Efficiency Hypothesis, Douglas R. Wood, Eric K. Bollinger

Eric K. Bollinger

Brown-headed Cowbirds (Molothrus ater) often remove host eggs, usually to the detriment of the host's reproductive success. We tested the hypothesis that host egg size and number influence the incubation efficiency of a parasitic egg. A single House Sparrow (Passer domesticus) or Brown-headed Cowbird egg was placed in each host nest (addition), and in some nests a host egg was removed as well (addition/removal). Hatching success and incubation length were measured to determine whether host-egg removal conferred an advantage in incubation efficiency compared to simple addition of a parasitic egg. Redwinged Blackbirds (Agelaius phoeniceus) and Chipping Sparrows (Spizella passerina) served …

Evolutionary Genetics And Genetic Variation Of Haplodiploids And X-Linked Genes, Philip W. Hedrick, Joel D. Parker

Joel D Parker

The evolutionary genetics of haplodiploids and X-linked genes share many features and are different from diploid (autosomal) genes in many respects. For example, the conditions for a stable polymorphism, the amount of genetic load, and the effective population size are all expected to be quite different between haplodiploids or X-linked genes and diploids. From experimental data, the genetic load for X-linked genes is much less than autosomal genes and appears less for haplodiploids than for diploids. The observed amount of molecular variation for haplodiploids is much less than that for diploids, even more so than predicted from the differences in …

Reinvigorating Introductory Biology: A Theme-Based, Investigative Approach To Teaching Biology Majors, Cynthia Norton, Lynne H. Gildensoph, Martha Phillips, Deborah Wygal, Kurt Olson, John Pellegrini, Kathleen Tweeten

Kurt Olson

No abstract provided.

Energetics Of Swimming By The Platypus Ornithorhynchus Anatinus: Metabolic Effort Associated With Rowing, Frank E. Fish, R V. Baudinette, P B. Frappell, M P. Sarre

Frank E. Fish

The metabolism of swimming in the platypus Ornithorhynchus anatinus Shaw was studied by measurement of oxygen consumption in a recirculating water flume. Platypuses swam against a constant water current of 0.45-1.0ms(-1). Animals used a rowing stroke and alternated bouts of surface and submerged swimming. Metabolic rate remained constant over the range of swimming speeds tested. The cost of transport decreased with increasing velocity to a minimum of 0.51 at 1.0ms(-1) Metabolic rate and cost of transport for the platypus were lower than values for semiaquatic mammals that swim at the water surface using a paddling mode. However, relative to transport …

Spiroplasma Lineolae Sp. Nov., From The Horsefly Tabanus Lineola (Diptera : Tabanidae), Frank E. French, Robert F. Whitcomb, Joseph G. Tully, Patricia Carle, Joseph M. Bové, Roberta B. Henegar, Jean R. Adams, Gail E. Gasparich, David L. Williamson

Gail Gasparich

Collaborative Roles For C-Jun N-Terminal Kinase, C-Jun, Serum Response Factor, And Sp1 In Calcium-Regulated Myocardial Gene Expression, Patrick M. Mcdonough, Deanna S. Hanford, Amy B. Sprenkle, Noel R. Mellon, Christopher C. Glembotski

Amy Sprenkle

Ms2 Coat Protein Mutants Which Bind Qβ Rna, Marc Spingola, David S. Peabody

Marc Spingola

Spiroplasma Chrysopicola Sp. Nov., Spiroplasma Gladiatoris Sp. Nov., Spiroplasma Helicoides Sp. Nov., And Spiroplasma Tabanidicola Sp. Nov., From Tabanid (Diptera: Tabanidae) Flies, Robert F. Whitcomb, Frank E. French, Joseph G. Tully, Gail E. Gasparich, David L. Rose, Patricia Carle, Joseph M. Bove, Roberta B. Henegar, Meghnad Konai, Kevin J. Hackett, Jean R. Adams, Truman B. Clark, David L. Williamson

Gail Gasparich

Opercular Jetting During Fast-Starts By Flatfishes, E L. Brainerd, B N. Page, Frank E. Fish

Frank E. Fish

When attacked by predators, flatfishes perform fast-starts that result in a rapid take-off from the ocean bottom on which they lie. High-speed video recordings of the blind side of flatfishes indicate that they expel a coherent jet of water from the blind-side opercular valve during take-off. Buccal pressure recordings in winter flounder (Pseudopleuronectes americanus) show that a buccal pressure pulse begins 0-20 ms before the beginning of the fast-start and has a range of mean magnitudes for three individuals of 1.6-10.7 kPa. We hypothesize that one function of the opercular jet in flatfishes may be to reduce the effects of …

Explanations For The Infrequent Cowbird Parasitism On Common Grackles, Brian D. Peer, Eric K. Bollinger

Eric K. Bollinger

We determined the factors responsible for the lack of parasitism on Common Grackles (Quiscalus quiscula) by Brown-headed Cowbirds (Molothrus ater). We found no evidence of parasitism on the 401 grackle nests we monitored in east-central Illinois. By the time cowbirds began laying eggs, 88.5% of all grackle nests were beyond the point of successful parasitism. Grackles rejected cowbird eggs more frequently during the prelaying stage of the nesting cycle (38.2%) compared to later stages (12.3%). Thirty-three cowbird eggs and nestlings were cross-fostered into grackle nests. Data were collected on 15 cowbird nestlings, of which three fledged. The cross-fostered cowbird eggs …

Comparative Leaf Anatomy And Systematics In Dendrobium, Sections Aporum And Rhizobium (Orchidaceae), Barbara S. Carlsward, William Lois Stern, Walter S. Judd, Terence W. Lucansky

Barbara S. Carlsward

The specialized leaf anatomy for species of Dendrobium within section Aporum is similar to that of species in section Rhizobium. In both sections leaves are characterized by a unifacial or nearly unifacial surface where the exposed surface is abaxial. However, leaves in section Rhizobium also feature a lacuna submerged in the mesophyll and surrounded by an adaxial epidermis. In contrast, leaves in section Aporum merely present an internal suture that divides the leaf into bilateral halves. These two sections of Dendrobium are hypothesized to be sister taxa because of synapomorphies in their foliar anatomy. A cladistic analysis performed with various …

Selective Predation On The Seeds Of Woody Plants, Scott J. Meiners, Edmund W. Stiles

Scott J. Meiners

Selective predation on the seeds of woody plants. J. Torrey Bot. Soc. 124: 67-70). 1997.-Seed predation may be an important factor influencing the structure of successional plant communities. We used a cafeteria-style experiment, placed in an old field and an early successional forest, to determine predator preferences for seeds of nine species of woody plants. Intensity of seed predation was equivalent in both sites. Seed predators preferred Acer saccharum, flex vertic illata, and Viburnum dentatum, but this was not related to seed mass. Predation intensity was more variable in the old field than in the forest, possibly related to the …

Methods Of Identifying The Avian Repellent Effects Of A Compound And Methods Of Repelling Birds From Materials Susceptible To Consumption By Birds, Larry Clark

Larry Clark

No abstract provided.

A Comparison Of Evolutionary Radiations In Mainland And West Indian Anolis Lizards. Ecology, Duncan J. Irschick, L. J. Vitt, P. Zani, J. B. Losos

Duncan J. Irschick

Comparisons between closely related radiations in different environments provide a unique window into understanding how abiotic and biotic factors shape evolutionary pathways. Anolis lizards have radiated extensively in the West Indies, as well as mainland Central and South America. In the Caribbean, similar communities of anole species specialized for different habitats (ecomorphs) have evolved independently on each Greater Antillean island. We examined ecological and morphological data on 49 Anolis species (33 Caribbean, 16 mainland) to investigate whether the same set of ecomorphs has arisen in mainland regions. More generally, we investigated whether the relationship between ecology and morphology was similar …

Cooperative Functions Of The Reaper And Head Involution Defective Genes In The Programmed Cell Death Of Drosophila Central Nervous System Midline Cells, Lawrence M. Schwartz, L. Zhou, A. Schnitzler, J. Agapite, H. Steller, J. R. Nambu

Lawrence M. Schwartz

In Drosophila, the chromosomal region 75C1–2 contains at least three genes, reaper (rpr), head involution defective (hid), and grim, that have important functions in the activation of programmed cell death. To better understand how cells are killed by these genes, we have utilized a well defined set of embryonic central nervous system midline cells that normally exhibit a specific pattern of glial cell death. In this study we show that both rpr and hid are expressed in dying midline cells and that the normal pattern of midline cell death requires the function of multiple genes in the 75C1–2 interval. We …

Social Interactions In Two Sympatric Salamanders: Effectiveness Of A Highly Aggressive Strategy, Carl D. Anthony, Jill A. Wicknick, Robert G. Jaeger

Carl D. Anthony

In terrestrial plethodontid salamanders, aggressive behaviour is thought to function in the spacing of territorial residents among contested cover objects on the forest floor. Such behaviour, when exhibited toward heterospecifics, plays an important role in the competitive interactions between species. We compared levels of aggressive behaviour in intra- and interspecific contexts in two species of sympatric salamanders (Plethodon ouachitae and P. albagula) that have similar ecological requirements but differ in adult size. We also tested the effectiveness of such behaviour in holding cover objects (territorial foci) in the laboratory and on the forest floor. We predicted that if one species …

Evidence That Elevated Co2 Leveles And Indirectly Increase Rhizosphere Denitrifier Activity, D. Smart, K. Ritchie, John M. Stark, Bruce Bugbee

John M. Stark

No abstract provided.

Anpassung - Kernpunkt Oder Mißverständnis Der Evolutionstheorie? [Adaptation - Essential Concept Or Misconception Of Evolutionary Biology?], Dieter Stefan Peters, Winfried Peters

Winfried S. Peters

Concerns And Priorities In Genetic Studies: Insights From Recent African American Biohistory, Fatimah Linda Collier Jackson

Fatimah Linda Collier Jackson

No abstract provided.

Effect Of Genome-Plastome Interaction On Meiosis And Pollen Development In Oenothera Species And Hybrids, Michael J. Chapman, David L. Mulcahy

David L. Mulcahy

Oenothera villaricae Dietrich and Oe. picensis Dietrich, complete translocation heterozygotes, are fully interfertile, giving rise to six discrete classes of true­ breeding hybrids from a reciprocal cross. Associated with each parent and hybrid is a characteristic ab01tive non­ staining pollen fraction easily distinguished from fully developed pollen under the light microscope. Pollen abortion has been associated with translocation rings in other angiosperm species, and may characterize such sys­ tems. The abortive pollen fraction is significantly differ­ ent between reciprocal Oenothera hybrids, however (P<0.001), indicative of partial cytoplasmic control. Pol­ len abortion is most severe in the F 1 hybrid …

Factors Influencing Maternal Behaviour In A Burrower Bug, Sehirus Cinctus (Heteroptera: Cydnidae), Scott Kight

Scott Kight

The Spiroplasma Motility Inhibition Test, A New Method For Determining Intraspecific Variation Among Colorado Potato Beetle Spiroplasmas, Kevin J. Hackett, J. J. Lipa, G. E. Gasparich, D. E. Lynn, M. Konai, M. Camp, R. F. Whitcomb

Gail Gasparich