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Evolution

University of Nebraska - Lincoln

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Full-Text Articles in Life Sciences

Exceptional Larval Morphology Of Nine Species Of The Anastrepha Mucronota Species Group (Diptera: Tephritidae), Erick J. Rodriguez, Gary J. Steck, Matthew R. Moore, Allen L. Norrbom, Jessica Diaz, Louis A. Somma, Raul Ruiz-Arce, Bruce D. Sutton, Norma Nolazco, Alies Muller, Marc A. Branham Nov 2022

Exceptional Larval Morphology Of Nine Species Of The Anastrepha Mucronota Species Group (Diptera: Tephritidae), Erick J. Rodriguez, Gary J. Steck, Matthew R. Moore, Allen L. Norrbom, Jessica Diaz, Louis A. Somma, Raul Ruiz-Arce, Bruce D. Sutton, Norma Nolazco, Alies Muller, Marc A. Branham

Papers in Evolution

Anastrepha is the most diverse and economically important genus of Tephritidae in the American tropics and subtropics. The striking morphology of the third instars of Anastrepha caballeroi Norrbom, Anastrepha crebra Stone, Anastrepha haplacantha Norrbom & Korytkowski, Anastrepha korytkowskii Norrbom, Anastrepha nolazcoae Norrbom & Korytkowski, and three newly discovered and as yet formally unnamed species (Anastrepha sp. Peru-82, Anastrepha sp. nr. protuberans, and Anastrepha sp. Sur-16), and the more typical morphology of Anastrepha aphelocentema Stone, are described using light and scanning electron microscopy. To contribute to a better understanding of the interspecific and intraspecific variation among species in the mucronota …


A Tale Of Two Genomes: The Complex Interplay Between The Mitochondrial And The Nuclear Genomes, Abhilesh S. Dhawanjewar Jul 2022

A Tale Of Two Genomes: The Complex Interplay Between The Mitochondrial And The Nuclear Genomes, Abhilesh S. Dhawanjewar

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

Mitochondria, the product of an ancient endosymbiotic event are pivotal to eukaryotic cells by synthesizing the majority of the cell’s ATP output. However, modern- day mitochondria are completely dependent on more than one thousand nuclear-encoded products for their function and the maintenance of their genomes. The fundamentally different ways in which the mitochondrial (mtDNA) and the nuclear (nucDNA) genomes are replicated and inherited lead to captivating coevolutionary dynamics between them. The aims of this dissertation are to investigate the coevolutionary dynamics between the mitochondrial and nuclear genomes at three distinct biological scales. At the organismal level, we use a Drosophila …


Nebraska Wildlife Club, Jacob Spooner Jul 2021

Nebraska Wildlife Club, Jacob Spooner

Honors Expanded Learning Clubs

The goal of this club was for students to expand their knowledge on wildlife that exists both in and outside of Nebraska and for them to get a better idea the types of wildlife they might be able to find within the state. In addition, an objective of this club was to spark curiosity so that the kids might try to further explore aspects of wildlife on their own.


James Davidson Fawcett (1933–2020): Imbibing With The Kiwi., Louis A. Somma Jun 2021

James Davidson Fawcett (1933–2020): Imbibing With The Kiwi., Louis A. Somma

Papers in Herpetology

An obituary and summary of the life of James D. Fawcett (1933-2020), herpetologist and instructor and professor of Biology at University of Nebraska at Omaha 1972-2015. Includes bibliography of his works, list of master's theses chaired, and recollections of former students.


Dog And Owner Characteristics Predict Training Success, Jeffrey R. Stevens, London M. Wolff, Megan Bosworth, Jill Morstad Jan 2021

Dog And Owner Characteristics Predict Training Success, Jeffrey R. Stevens, London M. Wolff, Megan Bosworth, Jill Morstad

Jeffrey Stevens Publications

Teaching owners how to train their dogs is an important part of maintaining the health and safety of dogs and people. Yet we do not know what behavioral characteristics of dogs and their owners are relevant to dog training or if owner cognitive abilities play a role in training success. The aim of this study is to determine which characteristics of both dogs and owners predict success in completing the American Kennel Club Canine Good Citizen training program. Before the first session of a dog training course, owners completed surveys evaluating the behavior and cognition of their dog and themselves. …


Are Capuchin Monkeys (Sapajus Spp.) Sensitive To Lost Opportunities? The Role Of Opportunity Costs In Intertemporal Choice, Elsa Addessi, Valeria Tierno, Valentina Focaroli, Federica Rossi, Serena Gastaldi, Francesca De Petrillo, Fabio Paglieri, Jeffrey R. Stevens Jan 2021

Are Capuchin Monkeys (Sapajus Spp.) Sensitive To Lost Opportunities? The Role Of Opportunity Costs In Intertemporal Choice, Elsa Addessi, Valeria Tierno, Valentina Focaroli, Federica Rossi, Serena Gastaldi, Francesca De Petrillo, Fabio Paglieri, Jeffrey R. Stevens

Jeffrey Stevens Publications

Principles of economics predict that the costs associated with obtaining rewards can influence choice. When individuals face choices between a smaller, immediate option and a larger, later option, they often experience opportunity costs associated with waiting for delayed rewards because they must forego the opportunity to make other choices. We evaluated how reducing opportunity costs affects delay tolerance in capuchin monkeys. After choosing the larger option, in the High cost condition, subjects had to wait for the delay to expire, whereas in the Low cost different and Low cost same conditions, they could perform a new choice during the delay. …


A Deeper Meaning For Shallow-Level Phylogenomic Studies: Nested Anchored Hybrid Enrichment Offers Great Promise For Resolving The Tiger Moth Tree Of Life (Lepidoptera: Erebidae: Arctiinae), Nicolas J. Dowdy, Shannon Keating, Alan R. Lemmon, Emily M. Lemmon, William E. Conner, Clare H. Scott Chialvo, Susan Weller, Rebecca B. Simmons, Melissa S. Sisson, Jennifer M. Zaspel Apr 2020

A Deeper Meaning For Shallow-Level Phylogenomic Studies: Nested Anchored Hybrid Enrichment Offers Great Promise For Resolving The Tiger Moth Tree Of Life (Lepidoptera: Erebidae: Arctiinae), Nicolas J. Dowdy, Shannon Keating, Alan R. Lemmon, Emily M. Lemmon, William E. Conner, Clare H. Scott Chialvo, Susan Weller, Rebecca B. Simmons, Melissa S. Sisson, Jennifer M. Zaspel

Department of Entomology: Faculty Publications

Anchored hybrid enrichment (AHE) has emerged as a powerful tool for uncovering the evolutionary relationships within many taxonomic groups. AHE probe sets have been developed for a variety of insect groups, though none have yet been shown to be capable of simultaneously resolving deep and very shallow (e.g., intraspecific) divergences. In this study, we present NOC1, a new AHE probe set (730 loci) for Lepidoptera specialized for tiger moths and assess its ability to deliver phylogenetic utility at all taxonomic levels. We test the NOC1 probe set with 142 individuals from 116 species sampled from all the major lineages of …


Ashfall Fossil Beds: From Waterhole To Rhino Barn, Sandy Mosel Jan 2020

Ashfall Fossil Beds: From Waterhole To Rhino Barn, Sandy Mosel

University of Nebraska State Museum: Programs Information

Twelve million years ago a volcanic super-eruption in what is now southwestern Idaho created an enormous ashfall that blanketed the Great Plains with several inches of volcanic ash, devastating the local wildlife. Evidence of this geologic event lies within the hills of the Niobrara River Valley in northeast Nebraska, at a place aptly named the Ashfall Fossil Beds State Historical Park. Located near the tiny village of Royal, the Ashfall Park has been developed around a waterhole where animals succumbed after breathing in the volcanic dust. Buried deeply by windblown volcanic ash in the weeks following the eruption, the skeletons …


Extreme Offspring Ornamentation In American Coots Is Favored By Selection Within Families, Not Benefits To Conspecific Brood Parasites, Bruce E. Lyon, Daizaburo Shizuka Jan 2020

Extreme Offspring Ornamentation In American Coots Is Favored By Selection Within Families, Not Benefits To Conspecific Brood Parasites, Bruce E. Lyon, Daizaburo Shizuka

School of Biological Sciences: Faculty Publications

Offspring ornamentation typically occurs in taxa with parental care, suggesting that selection arising from social interactions between parents and offspring may underlie signal evolution. American coot babies are among the most ornamented offspring found in nature, sporting vividly orange-red natal plumage, a bright red beak, and other red parts around the face and pate. Previous plumage manipulation experiments showed that ornamented plumage is favored by strong parental choice for chicks with more extreme ornamentation but left unresolved the question as to why parents show the preference. Here we explore natural patterns of variation in coot chick plumage color, both within …


Individual Based Model To Simulate The Evolution Of Insecticide Resistance, William B. Jamieson Dec 2019

Individual Based Model To Simulate The Evolution Of Insecticide Resistance, William B. Jamieson

Department of Mathematics: Dissertations, Theses, and Student Research

Insecticides play a critical role in agricultural productivity. However, insecticides impose selective pressures on insect populations, so the Darwinian principles of natural selection predict that resistance to the insecticide is likely to form in the insect populations. Insecticide resistance, in turn, severely reduces the utility of the insecticides being used. Thus there is a strong economic incentive to reduce the rate of resistance evolution. Moreover, resistance evolution represents an example of evolution under novel selective pressures, so its study contributes to the fundamental understanding of evolutionary theory.

Insecticide resistance often represents a complex interplay of multiple fitness trade-offs for individual …


Traffic Noise And Sexual Selection: Studies Of Anthropogenic Impact On Bird Songs And Undergraduate Student Reasoning Of Evolutionary Mechanisms, Sarah Spier Aug 2019

Traffic Noise And Sexual Selection: Studies Of Anthropogenic Impact On Bird Songs And Undergraduate Student Reasoning Of Evolutionary Mechanisms, Sarah Spier

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

Humans have transformed much of the natural landscape and are continuing to do so at an accelerated rate, compromising natural areas that serve as important habitat for many species. Roads impact much of the environment as they fragment habitat and introduce traffic noise into the acoustic environment, deferentially affecting wildlife in roadside habitat. I explored how traffic noise affects the detection of birds based on whether their vocalizations were masked by traffic noise. Masked species detection was not affected by an increase in traffic noise amplitude, while there was a negative effect of traffic noise amplitude on unmasked species detection, …


Plant Mitochondrial Genome Evolution And Structure Has Been Shaped By Double-Strand Break Repair And Recombination, Emily Wynn Apr 2019

Plant Mitochondrial Genome Evolution And Structure Has Been Shaped By Double-Strand Break Repair And Recombination, Emily Wynn

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

Plant mitochondrial genomes are large but contain a small number of genes. These genes have very low mutation rates, but genomes rearrange and expand at significant rates. We propose that much of the apparent complexity of plant mitochondrial genomes can be explained by the interactions of double-strand break repair, recombination, and selection. One possible explanation for the disparity between the low mutation rates of genes and the high divergence of non-genes is that synonymous mutations in genes are not truly neutral. In some species, rps14 has been duplicated in the nucleus, allowing the mitochondrial copy to become a pseudogene. By …


Changes In North American Mammal Niche Preferences From The Late Pleistocene To The Present, Silvia Pineda-Munoz, Anikó Tóth, S. Kathleen Lyons, Yue Wang, Jenny Mcguire Jan 2019

Changes In North American Mammal Niche Preferences From The Late Pleistocene To The Present, Silvia Pineda-Munoz, Anikó Tóth, S. Kathleen Lyons, Yue Wang, Jenny Mcguire

School of Biological Sciences: Posters and Presentations

Human population has exponentially grown since the last glaciation, especially across temperate areas with easy access to water sources, excluding mammal species from their former habitats. Thus, we anticipate a change in environmental niche preferences for temperature and precipitation as increased human population forces mammal species into more extreme climates within their environmental tolerances. For our study, we collected species occurrences from 20,000 ybp to the present for 59 North American mammal species. We inferred temperature and precipitation for each location using paleoclimate simulations (CCSM3). Overall, we found that mammals now live in areas that are warmer and dryer on …


Novel Information On The Morphology, Phylogeny And Distribution Of Camallanid Mematodes From Marine And Freshwater Hosts In South Africa, Including The Description Of Camallanus Sodwanaensis N. Sp., Roman Svitin, Marliese Truter, Olena Kudlai, Nico J. Smit, Louis Du Preez Jan 2019

Novel Information On The Morphology, Phylogeny And Distribution Of Camallanid Mematodes From Marine And Freshwater Hosts In South Africa, Including The Description Of Camallanus Sodwanaensis N. Sp., Roman Svitin, Marliese Truter, Olena Kudlai, Nico J. Smit, Louis Du Preez

Harold W. Manter Laboratory: Library Materials

Four species of previously known nematodes from the family Camallanidae were found from different hosts in South Africa: Batrachocamallanus xenopodis from the frog Xenopus muelleri, Paracamallanus cyathopharynx, and Procamallanus pseudolaeviconchus from the catfish Clarias gariepinus and Spirocamallanus daleneae from the catfish Synodontis zambezensis. In the material collected from various marine fishes, several specimens of nematodes from the genus Camallanus clearly differed from all previously known species. Based on morphological differences these specimens are assigned to a new species, C. sodwanaensis. Molecular data of 18S and 28S rDNA and COI sequences are provided for the collected species …


Males And Females Evolve Riskier Traits In Populations With Eavesdropping Parasitoids, Oliver M. Beckers, William E. Wagner Oct 2018

Males And Females Evolve Riskier Traits In Populations With Eavesdropping Parasitoids, Oliver M. Beckers, William E. Wagner

School of Biological Sciences: Faculty Publications

Predation and/or parasitism often limits the evolution of conspicuous male traits and female preferences because conspicuous traits can attract predators or parasites and it is costly for females to associate with males that attract predators or parasites. As a result, males and females in high-risk populations are expected to evolve safer mating behaviors compared to individuals from low-risk populations. We tested this antagonistic selection hypothesis in the field cricket Gryllus lineaticeps. Males produce chirped songs, and both female crickets and the eavesdropping parasitoid fly Ormia ochracea prefer faster chirp rates. The flies attack the field crickets late in the …


Energetic Tradeoffs Control The Size Distribution Of Aquatic Mammals, William Gearty, Craig R. Mcclain, Jonathan Payne Apr 2018

Energetic Tradeoffs Control The Size Distribution Of Aquatic Mammals, William Gearty, Craig R. Mcclain, Jonathan Payne

School of Biological Sciences: Faculty Publications

Four extant lineages of mammals have invaded and diversified in the water: Sirenia, Cetacea, Pinnipedia, and Lutrinae. Most of these aquatic clades are larger bodied, on average, than their closest land-dwelling relatives, but the extent to which potential ecological, biomechanical, and physiological controls contributed to this pattern remains untested quantitatively. Here, we use previously published data on the body masses of 3,859 living and 2,999 fossil mammal species to examine the evolutionary trajectories of body size in aquatic mammals through both comparative phylogenetic analysis and examination of the fossil record. Both methods indicate that the evolution of an aquatic lifestyle …


Convergent Body Size Evolution Of Crocodyliformes Upon Entering The Aquatic Realm, William Gearty, Jonathan Payne Jan 2018

Convergent Body Size Evolution Of Crocodyliformes Upon Entering The Aquatic Realm, William Gearty, Jonathan Payne

School of Biological Sciences: Posters and Presentations

Twenty-four species of crocodile populate the globe today, but this richness represents a minute fraction of the diversity and disparity of Crocodyliformes since their origin early in the Triassic. Across this clade, three major diversification events into the aquatic realm have occurred. Aquatic and terrestrial habitats impose differing selective pressures on body size. However, previous research on this topic in Crocodyliformes remains qualitative in nature. In this study, our goal was to quantify the influence of habitat (terrestrial versus aquatic) on the evolution of body size in Crocodyliformes. We find a history of repeated body size increase and convergence following …


Social Contact Patterns Can Buffer Costs Of Forgetting In The Evolution Of Cooperation, Jeffrey R. Stevens, Jan K. Woike, Lael J. Schooler, Stefan Lindner, Thorsten Pachur Jan 2018

Social Contact Patterns Can Buffer Costs Of Forgetting In The Evolution Of Cooperation, Jeffrey R. Stevens, Jan K. Woike, Lael J. Schooler, Stefan Lindner, Thorsten Pachur

Jeffrey Stevens Publications

Analyses of the evolution of cooperation often rely on two simplifying assumptions: (i) individuals interact equally frequently with all social network members and (ii) they accurately remember each partner's past cooperation or defection. Here, we examine how more realistic, skewed patterns of contact—in which individuals interact primarily with only a subset of their network's members—influence cooperation. In addition, we test whether skewed contact patterns can counteract the decrease in cooperation caused by memory errors (i.e. forgetting). Finally, we compare two types of memory error that vary in whether forgotten interactions are replaced with random actions or with actions from previous …


Mesotocin Influences Pinyon Jay Prosociality, Juan Duque, Whitney Leichner, Holly Ahmann, Jeffrey R. Stevens Jan 2018

Mesotocin Influences Pinyon Jay Prosociality, Juan Duque, Whitney Leichner, Holly Ahmann, Jeffrey R. Stevens

Jeffrey Stevens Publications

Many species exhibit prosocial behavior, in which one individual’s actions benefit another individual, often without an immediate benefit to itself. The neuropeptide oxytocin is an important hormonal mechanism influencing prosociality in mammals, but it is unclear whether the avian homologue mesotocin plays a similar functional role in birds. Here, we experimentally tested prosociality in pinyon jays (Gymnorhinus cyanocephalus), a highly social corvid species that spontaneously shares food with others. First, we measured prosocial preferences in a prosocial choice task with two different payoff distributions: Prosocial trials delivered food to both the subject and either an empty cage or a partner …


The North American Quails, Partridges, And Pheasants, Paul A. Johnsgard Oct 2017

The North American Quails, Partridges, And Pheasants, Paul A. Johnsgard

Zea E-Books Collection

This book documents the biology of six species of New World quails that are native to North America north of Mexico (mountain, scaled, Gambel’s, California, and Montezuma quails, and the northern bobwhite), three introduced Old World partridges (chukar, Himalayan snowcock, and gray partridge), and the introduced common (ring-necked) pheasant. Collectively, quails, partridges, and pheasants range throughout all of the continental United States and the Canadian provinces. Two of the species, the northern bobwhite and ring-necked pheasant, are the most economically important of all North American upland game birds. All of the species are hunted extensively for sport and are highly …


Is Cooperative Memory Special? The Role Of Costly Errors, Context, And Social Network Size When Remembering Cooperative Actions, Jeffrey R. Stevens, Tim Winke Oct 2017

Is Cooperative Memory Special? The Role Of Costly Errors, Context, And Social Network Size When Remembering Cooperative Actions, Jeffrey R. Stevens, Tim Winke

Jeffrey Stevens Publications

Theoretical studies of cooperative behavior have focused on decision strategies, such as tit-for-tat, that depend on remembering a partner’s last choices. Yet, an empirical study by Stevens et al. (2011) demonstrated that human memory may not meet the requirements that needed to use these strategies. When asked to recall the previous behavior of simulated partners in a cooperative memory task, participants performed poorly, making errors in 10–24% of the trials. However, we do not know the extent to which this task taps specialized cognition for cooperation. It may be possible to engage participants in more cooperative, strategic thinking, which may …


Answers To Common Misconceptions About Biological Evolution, Leah M. Abebe, Blake Bartels, Kaitlyn M. Caron, Adam M. Gleeson, Samuel N. Johnson, Tyler J. Kluza, Nicholas W. Knopik, Kristen N. Kramer, Masiel S. Maza, Kaitlyn A. Stava, Kaitlyn Sullivan, Jordan T. Trimble, Robert M. Zink , Editor May 2017

Answers To Common Misconceptions About Biological Evolution, Leah M. Abebe, Blake Bartels, Kaitlyn M. Caron, Adam M. Gleeson, Samuel N. Johnson, Tyler J. Kluza, Nicholas W. Knopik, Kristen N. Kramer, Masiel S. Maza, Kaitlyn A. Stava, Kaitlyn Sullivan, Jordan T. Trimble, Robert M. Zink , Editor

Papers in Evolution

“When you have an established scientific emergent truth, it is true whether or not you believe in it.” Neil deGrasse Tyson, Science in America. Very few people outside of a particular scientific discipline can actually say they understand it, because most do not have the training to “speak the language.” They are then not particularly bothered by its tenets and predictions. Of all the major branches of science, however, evolutionary biology is an exception to this generalization because even though people are not versed in the field, they sometimes have a negative, knee-jerk objection. This objection is often because they …


Behavioral Plasticity Across Non-Social Contexts In Female Green Swordtails, Xiphophorus Hellerii, Lindsey M. Coit May 2017

Behavioral Plasticity Across Non-Social Contexts In Female Green Swordtails, Xiphophorus Hellerii, Lindsey M. Coit

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

Phenotypic plasticity is the ability of an individual to alter its phenotype in response to environmental change. Individuals that express plasticity in behavior can quickly respond to changes that occur in the environment. Therefore, individuals that exhibit behavioral plasticity can alter their behavioral expression to best match current environmental conditions. The degree and direction of behavioral plasticity may be influenced by variation in individual characteristics. Understanding how variation in individual traits affects behavioral plasticity, and, whether patterns of behavioral plasticity are consistent across behavioral contexts are important topics to explore as we try to better understand how plasticity evolves and …


Patterns Of Morphological And Molecular Evolution In The Antillean Tree Bat, Ardops Nichollsi (Chiroptera: Phyllostomidae), Roxanne J. Larsen, Peter A. Larsen, Caleb D. Phillips, Hugh H. Genoways, Gary G. Kwiecinski, Scott C. Pedersen, Carleton J. Phillips, Robert J. Baker Mar 2017

Patterns Of Morphological And Molecular Evolution In The Antillean Tree Bat, Ardops Nichollsi (Chiroptera: Phyllostomidae), Roxanne J. Larsen, Peter A. Larsen, Caleb D. Phillips, Hugh H. Genoways, Gary G. Kwiecinski, Scott C. Pedersen, Carleton J. Phillips, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

Species endemic to oceanic islands offer unique insights into the mechanisms underlying evolution and have served as model systems for decades. Often these species show phenotypic variation that is correlated with the ecosystems in which they occur and such correlations may be a product of genetic drift, natural selection, and/or environmental factors. We explore the morphologic and genetic variation within Ardops nichollsi, a species of phyllostomid bat endemic to the Lesser Antillean islands. Ardops nichollsi is an ideal taxon to investigate the tempo of evolution in Chiroptera, as it: is a recently derived genus in the family Phyllostomidae; contains …


Use Of Erroneous Wolf Generation Time In Assessments Of Domestic Dog And Human Evolution, L. David Mech Feb 2017

Use Of Erroneous Wolf Generation Time In Assessments Of Domestic Dog And Human Evolution, L. David Mech

USGS Northern Prairie Wildlife Research Center

Scientific interest in dog domestication and parallel evolution of dogs and humans (1) has increased recently (2-4), and various important conclusions have been drawn based on how long ago the calculations show dogs were domesticated from ancestral wolves (Canis lupus). According to Skoglund et al. (2015:3), calculation of this duration is based on “the most commonly assumed mutation rate of 1 x 10-8 per generation and a 3-year gray wolf generation time . . .” (5). It is unclear on what information the assumed generation time is based, but the latest paper (6) seems to have based generation time on …


Five Species Of Fossil Equids Preserved In-Situ At Ashfall Fossil Beds, Rick E. Otto Jan 2017

Five Species Of Fossil Equids Preserved In-Situ At Ashfall Fossil Beds, Rick E. Otto

University of Nebraska State Museum: Programs Information

Fully articulated, three-dimensionally preserved skeletons from five species of fossil Equids are now represented, and preserved in-situat the Ashfall Fossil Beds in northcentral Nebraska. The site is well known for dozens of barrel-bodied rhino (Teleoceras major) skeletons. A diversity of horse species that inhabited Nebraska during the late Miocene Epoch have been exposed in the fossil bed. Genera include Cormohipparion, Neohipparon, Pliohippus, Protohippus, and Pseudhipparion. An exceptionally well-preserved skeleton of the small-sized, three-toed species Pseudhipparion gratumwas recently exposed, and is on display only a few feet from where visitors stand.


Rewiring Metabolism Under Oxygen Deprivation: Naked Mole-Rats Evolved A Means To Cope With Anoxia, Jay F. Storz, Grant B. Mcclelland Jan 2017

Rewiring Metabolism Under Oxygen Deprivation: Naked Mole-Rats Evolved A Means To Cope With Anoxia, Jay F. Storz, Grant B. Mcclelland

Jay F. Storz Publications

When faced with a reduced availability of oxygen in the environment (hypoxia), vertebrates can make a variety of respiratory, cardiovascular, and hematological adjustments to ensure an uninterrupted supply of oxygen to the cells of metabolizing tissues (1, 2). These are adaptive solutions for “aerobic organisms in an aerobic world” (3). Coping with the complete absence of oxygen (anoxia) requires more fundamental alterations of cellular metabolism that are typically nothing more than emergency stopgap measures to buy time until the oxygen supply is (hopefully) reestablished (4). On page 307 of this issue [Science 356 (6335)], Park et al. (5) identify a …


Intertemporal Choice And Delayed Gratification, Jeffrey R. Stevens Jan 2017

Intertemporal Choice And Delayed Gratification, Jeffrey R. Stevens

Jeffrey Stevens Publications

A parasitoid wasp has deposited half of her eggs in a host. She now faces the choice between depositing her remaining eggs in the same host or searching for another. Continuing to deposit in the current host provides the immediate payoff of completing her reproductive duties, allowing her to move on to other activities such as foraging or searching for another mate. Searching for another host, in contrast, delays the payoffs of reproducing until a suitable host is found. This wasp faces an intertemporal choice—that is, a choice between options that involve payoffs available at different times (Read, 2004; Stevens, …


Changes In Male Hunting Returns, Raymond B. Hames Dec 2016

Changes In Male Hunting Returns, Raymond B. Hames

Department of Anthropology: Faculty Publications

Research on changes in male hunting among hunter-gatherers addresses two important issues in early human evolution: the nature of the family and trade-offs in mating and parenting effort as well as the development of embodied capital. In the hunter-gatherer literature, there is a debate about the function of male hunting that has implications for understanding the role males play in the evolution of the pair bond. The traditional model argues that male hunting and other economic activities are forms of male provisioning or parenting effort designed to enhance a man’s fitness through his wife’s reproduction and the survivorship of their …


Inter- And Intra-Individual Variation In Predator-Related Behavioral Plasticity Expressed By Female Green Swordtails (Xiphophorus Hellerii), Rachael A. Disciullo Nov 2016

Inter- And Intra-Individual Variation In Predator-Related Behavioral Plasticity Expressed By Female Green Swordtails (Xiphophorus Hellerii), Rachael A. Disciullo

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

Phenotypic plasticity is the ability of one genotype to express multiple phenotypes under variable environments. Behavioral plasticity is a type of phenotypic plasticity in which individuals adjust behavior in response to changes in environment. Often, behavioral plasticity is studied at the level of the population, rather than at the level of the individual. Further, few studies have considered the effect of individual traits, such as size and age, on the expression of behavioral plasticity, or, how individual plasticity may be correlated across different contexts. In this study, we used female green swordtails (Xiphophorus hellerii) to test the effects …