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Articles 1 - 11 of 11

Full-Text Articles in Population Biology

Dynamic Observers For Unknown Populations, Chris Guiver, Nathan Poppelreiter, Richard Rebarber, Brigitte Tenhumberg, Stuart Townley Jun 2021

Dynamic Observers For Unknown Populations, Chris Guiver, Nathan Poppelreiter, Richard Rebarber, Brigitte Tenhumberg, Stuart Townley

Brigitte Tenhumberg Papers

Dynamic observers are considered in the context of structuredpopulation modeling and management. Roughly, observers combine a known measured variable of some process with a model of that process to asymptotically reconstruct the unknown state variable of the model. We investigate the potential use of observers for reconstructing population distributions described by density-independent (linear) models and a class of density-dependent (nonlinear) models. In both the density-dependent and -independent cases, we show, in several ecologically reasonable circumstances, that there is a natural, optimal construction of these observers. Further, we describe the robustness these observers exhibit with respect to disturbances and uncertainty in …


Contemporary Sexual Selection Does Not Explain Variation In Male Display Traits Among Populations, J. Colton Watts, Allissa Flynn, Brigitte Tenhumberg, Eileen Hebets Jan 2019

Contemporary Sexual Selection Does Not Explain Variation In Male Display Traits Among Populations, J. Colton Watts, Allissa Flynn, Brigitte Tenhumberg, Eileen Hebets

Brigitte Tenhumberg Papers

Sexual selection is widely hypothesized to facilitate the evolution of reproductive isolation through divergence in sexual traits and sexual trait preferences among populations. However, direct evidence of divergent sexual selection causing intraspecific trait divergence remains limited. Using the wolf spider Schizocosa crassipes, we characterized patterns of female mate choice within and among geographic locations and related those patterns to geographic variation in male display traits to test whether divergent sexual selection caused by mate choice explains intraspecific trait variation. We found evidence of phenotypic selection on male behavior arising from female mate choice, but no evidence that selection varied …


The Maintenance Of Phenotypic Divergence Through Sexual Selection: An Experimental Study In Barn Swallows Hirundo Rustica, Rebecca Safran, Yoni Vortman, Brittany R. Jenkins, Joanna K. Hubbard, Matt Wilkins, Rachel J. Bradley, Arnon Lotem Jul 2016

The Maintenance Of Phenotypic Divergence Through Sexual Selection: An Experimental Study In Barn Swallows Hirundo Rustica, Rebecca Safran, Yoni Vortman, Brittany R. Jenkins, Joanna K. Hubbard, Matt Wilkins, Rachel J. Bradley, Arnon Lotem

School of Biological Sciences: Faculty Publications

Previous studies have shown that sexual signals can rapidly diverge among closely related species. However, we lack experimental studies to demonstrate that differences in trait-associated reproductive performance maintain sexual trait differences between closely related populations, in support for a role of sexual selection in speciation. Populations of Northern Hemisphere distributed barn swallows Hirundo rustica are closely related, yet differ in two plumage-based traits: ventral color and length of the outermost tail feathers (streamers). Here we provide experimental evidence that manipulations of these traits result in different reproductive consequences in two subspecies of barn swallow: (H. r. erythrogaster in North …


Molecular Analysis Confirming The Introduction Of Nile Crocodiles, Crocodylus Niloticus Laurenti 1768 (Crocodylidae), In Southern Florida, With An Assessment Of Potential For Establishment, Spread, And Impacts., Michael R. Rochford, Kenneth L. Krysko, Frank J. Mazzotti, Matthew W. Shirley, Mark W. Parry, Joseph A. Wasilewski, Jeffrey S. Beauchamp, Christpher R. Gillette, Edward F. Metzger Iii, Michiko A. Squires, Louis A. Somma Apr 2016

Molecular Analysis Confirming The Introduction Of Nile Crocodiles, Crocodylus Niloticus Laurenti 1768 (Crocodylidae), In Southern Florida, With An Assessment Of Potential For Establishment, Spread, And Impacts., Michael R. Rochford, Kenneth L. Krysko, Frank J. Mazzotti, Matthew W. Shirley, Mark W. Parry, Joseph A. Wasilewski, Jeffrey S. Beauchamp, Christpher R. Gillette, Edward F. Metzger Iii, Michiko A. Squires, Louis A. Somma

Papers in Herpetology

The state of Florida, USA, has more introduced herpetofauna than any other governmental region on Earth. Four species of nonnative crocodilians have been introduced to Florida (all since 1960), one of which is established. Between 2000–2014 we field-collected three nonnative crocodilians in Miami-Dade County, Florida, and one in Hendry County, Florida. We used DNA barcoding and molecular phylogenetics to determine species identification and native range origin. Also, we described diet, movement, and growth for one crocodile. Our molecular analyses illustrated that two of the crocodiles we collected are most closely related to Nile Crocodiles (Crocodylus niloticus) from South Africa, suggesting …


Comparative Population Genomics Of Latitudinal Variation In Drosophila Simulans And Drosophila Melanogaster, Heather E. Machado, Alan O. Bergland, Katherine R. O'Brien, Emily L. Behrman, Paul S. Schmidt, Dmitri A. Petrov Feb 2016

Comparative Population Genomics Of Latitudinal Variation In Drosophila Simulans And Drosophila Melanogaster, Heather E. Machado, Alan O. Bergland, Katherine R. O'Brien, Emily L. Behrman, Paul S. Schmidt, Dmitri A. Petrov

School of Biological Sciences: Faculty Publications

Examples of clinal variation in phenotypes and genotypes across latitudinal transects have served as important models for understanding how spatially varying selection and demographic forces shape variation within species. Here, we examine the selective and demographic contributions to latitudinal variation through the largest comparative genomic study to date of Drosophila simulans and Drosophila melanogaster, with genomic sequence data from 382 individual fruit flies, collected across a spatial transect of 19 degrees latitude and at multiple time points over 2 years. Consistent with phenotypic studies, we find less clinal variation in D. simulans than D. melanogaster, particularly for the autosomes. Moreover, …


Genetic And Genomic Basis Of Antibody Response To Porcine Reproductive And Respiratory Syndrome (Prrs) In Gilts And Sows, Nick V. Serão, Robert A. Kemp, Benny Mote, Philip Willson, John C.S. Harding, Stephen C. Bishop, Graham S. Plastow, Jack C.M. Dekkers Jan 2016

Genetic And Genomic Basis Of Antibody Response To Porcine Reproductive And Respiratory Syndrome (Prrs) In Gilts And Sows, Nick V. Serão, Robert A. Kemp, Benny Mote, Philip Willson, John C.S. Harding, Stephen C. Bishop, Graham S. Plastow, Jack C.M. Dekkers

Department of Animal Science: Faculty Publications

Background: Our recent research showed that antibody response to porcine reproductive and respiratory syndrome (PRRS), measured as sample-to-positive (S/P) ratio, is highly heritable and has a high genetic correlation with reproductive performance during a PRRS outbreak. Two major quantitative trait loci (QTL) on Sus scrofa chromosome 7 (SSC7; QTLMHC and QTL130) accounted for ~40 % of the genetic variance for S/P. Objectives of this study were to estimate genetic parameters for PRRS S/P in gilts during acclimation, identify regions associated with S/P, and evaluate the accuracy of genomic prediction of S/P across populations with different prevalences of …


A Robust New Metric Of Phenotypic Distance To Estimate And Compare Multiple Trait Differences Among Populations, Rebecca Safran, Samuel Flaxman, Michael Kopp, Darren E. Irwin, Derek Briggs, Matthew R. Evans, W. Chris Funk, David A. Gray, Eileen A. Hebets, Nathalie Seddon, Elizabeth Scordato, Laurel B. Symes, Joseph A. Tobias, David P.L. Toews, J. Albert C. Uy Jan 2012

A Robust New Metric Of Phenotypic Distance To Estimate And Compare Multiple Trait Differences Among Populations, Rebecca Safran, Samuel Flaxman, Michael Kopp, Darren E. Irwin, Derek Briggs, Matthew R. Evans, W. Chris Funk, David A. Gray, Eileen A. Hebets, Nathalie Seddon, Elizabeth Scordato, Laurel B. Symes, Joseph A. Tobias, David P.L. Toews, J. Albert C. Uy

Eileen Hebets Publications

Whereas a rich literature exists for estimating population genetic divergence, metrics of phenotypic trait divergence are lacking, particularly for comparing multiple traits among three or more populations. Here, we review and analyze via simulation Hedges’ g, a widely used parametric estimate of effect size. Our analyses indicate that g is sensitive to a combination of unequal trait variances and unequal sample sizes among populations and to changes in the scale of measurement. We then go on to derive and explain a new, non-parametric distance measure, “Δp”, which is calculated based upon a joint cumulative distribution function (CDF) from all …


Herbicide-Resistant Risk Assessment: Response Of Common Nebraska Weeds To Dicamba Dose, Roberto J. Crespo Jul 2011

Herbicide-Resistant Risk Assessment: Response Of Common Nebraska Weeds To Dicamba Dose, Roberto J. Crespo

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Dicamba-resistant soybeans are being developed to provide an additional herbicide mechanism of action that can be used in soybean, and to provide a tool to help manage or mitigate the evolution of other herbicide-resistant weed populations. The objectives of this thesis were to assess the risk of common Nebraska weeds developing resistance to dicamba, quantify baseline dose-response to dicamba of high-risk weed species, and survey the variability in dicamba dose-response among populations of those species. Twenty-five weed scientists were asked to estimate the risk likelihood of ten weed species evolving resistance to dicamba following the commercialization of dicamba-resistant soybean. Palmer …


Thirty-Seven Additional Microsatellite Loci In The Pacific Lion-Paw Scallop (Nodipecten Subnodosus) And Cross-Amplification In Other Pectinids, Jessica Lynn Petersen, Ana M. Ibarra, Bernie May Jan 2009

Thirty-Seven Additional Microsatellite Loci In The Pacific Lion-Paw Scallop (Nodipecten Subnodosus) And Cross-Amplification In Other Pectinids, Jessica Lynn Petersen, Ana M. Ibarra, Bernie May

Department of Animal Science: Faculty Publications

We characterized 37 new microsatellite markers in the Pacific lion-paw scallop (Nodipecten subnodosus) and tested for cross-amplification in four other species. Genetic diversity was estimated using 24 individuals from the Lagoon Ojo de Liebre, B.C.S., Mexico. Allelic richness varied from 5 to 27 alleles per locus and the average expected heterozygosity was 0.76. Ten loci exhibited significant departure from Hardy–Weinberg equilibrium likely due to the presence of null alleles. Sixteen of these markers cross-amplified in closely related N. nodosus, while little or no amplification was observed in three Argopecten species.


Simpler Mode Of Inheritance Of Transcriptional Variation In Male Drosophila Melanogaster, Marta Wayne, Marina Telonis-Scott, Lisa Bono, Lawrence G. Harshman, Artyom Kopp, Sergey V. Nuzhdin, Lauren Mcintyre Nov 2007

Simpler Mode Of Inheritance Of Transcriptional Variation In Male Drosophila Melanogaster, Marta Wayne, Marina Telonis-Scott, Lisa Bono, Lawrence G. Harshman, Artyom Kopp, Sergey V. Nuzhdin, Lauren Mcintyre

Lawrence G. Harshman Publications

Sexual selection drives faster evolution in males. The X chromosome is potentially an important target for sexual selection, because hemizygosity in males permits accumulation of alleles, causing tradeoffs in fitness between sexes. Hemizygosity of the X could cause fundamentally different modes of inheritance between the sexes, with more additive variation in males and more nonadditive variation in females. Indeed, we find that genetic variation for the transcriptome is primarily additive in males but nonadditive in females. As expected, these differences are more pronounced on the X chromosome than the autosomes, but autosomal loci are also affected, possibly because of X-linked …


Plant Hybrid Zones And Insect Host Range Expansion, Diana Pilson Jan 1999

Plant Hybrid Zones And Insect Host Range Expansion, Diana Pilson

Diana Pilson Publications

The hybrid bridge hypothesis suggests that plant hybrids ‘‘bridge’’ the genetic gap between actual and potential host species, and that, for this reason, herbivorous insects are more likely to evolve an expanded host range in the presence of hybrids. While intuitively appealing, the hypothesis has two implicit assumptions: that phenotypic gaps between potential hosts limit host range, and that characters controlling host use are additively inherited in plant hybrids. Evaluation of these assumptions suggests that operation of the hybrid bridge hypothesis is relatively uncommon. In addition, the hypothesis has not been well integrated into existing theoretical and empirical work on …