Life Sciences Commons^™

Quantifying Antarctic Krill Connectivity Across The West Antarctic Peninsula And Its Role In Large-Scale Pygoscelis Penguin Population Dynamics, Katherine L. Gallagher, Michael S. Dinniman, Heather J. Lynch

CCPO Publications

Antarctic krill (Euphausia superba) are considered a keystone species for higher trophic level predators along the West Antarctic Peninsula (WAP) during the austral summer. The connectivity of krill may play a critical role in predator biogeography, especially for central-place foragers such as the Pygoscelis spp. penguins that breed along the WAP during the austral summer. Antarctic krill are also heavily fished commercially; therefore, understanding population connectivity of krill is critical to effective management. Here, we used a physical ocean model to examine adult krill connectivity in this region using simulated krill with realistic diel vertical migration behaviors across …

Fgf-Signaling Is Compartmentalized Within The Mesenchyme And Controls Proliferation During Salamander Limb Development, Sruthi Purushothaman, Ahmed Elewa, Ashley W. Seifert

Biology Faculty Publications

Although decades of studies have produced a generalized model for tetrapod limb development, urodeles deviate from anurans and amniotes in at least two key respects: their limbs exhibit preaxial skeletal differentiation and do not develop an apical ectodermal ridge (AER). Here, we investigated how Sonic hedgehog (Shh) and Fibroblast growth factor (Fgf) signaling regulate limb development in the axolotl. We found that Shh-expressing cells contributed to the most posterior digit, and that inhibiting Shh-signaling inhibited Fgf8 expression, anteroposterior patterning, and distal cell proliferation. In addition to lack of a morphological AER, we found that salamander …

Embryonic Origin And Genetic Basis Of Cave Associated Phenotypes In The Isopod Crustacean Asellus Aquaticus., Hafasa Mojaddidi, Franco Fernandez, Priscilla A. Erickson, Meredith E. Protas

Natural Sciences and Mathematics | Faculty Scholarship

Characteristics common to animals living in subterranean environments include the reduction or absence of eyes, lessened pigmentation and enhanced sensory systems. How these characteristics have evolved is poorly understood for the majority of cave dwelling species. In order to understand the evolution of these changes, this study uses an invertebrate model system, the freshwater isopod crustacean, Asellus aquaticus, to examine whether adult differences between cave and surface dwelling individuals first appear during embryonic development. We hypothesized that antennal elaboration, as well as eye reduction and pigment loss, would be apparent during embryonic development. We found that differences in pigmentation, eye …

Quantifying Climate Sensitivity And Climate-Driven Change In North American Amphibian Communities, David A. W. Miller, Evan H Campbell Grant, Erin Muths, Staci M. Amburgey, Michael J. Adams, Maxwell B. Joseph, J. Hardin Waddle, Pieter T. J. Johnson, Maureen E. Ryan, Benedikt R. Schmidt, Daniel L. Calhoun, Courtney L. Davis, Robert N. Fisher, David M. Green, Blake R. Hossack, Tracy A. G. Rittenhouse, Susan C. Walls, Larissa L. Bailey, Sam S. Cruickshank, Gary M. Fellers, Thomas A. Gorman, Carola A. Haas, Ward Hughson, David S. Pilliod, Steve J. Price, Andrew M. Ray, Walt Sadinski, Daniel Saenz, William J. Barichivich, Adrianne Brand

Forestry and Natural Resources Faculty Publications

Changing climate will impact species’ ranges only when environmental variability directly impacts the demography of local populations. However, measurement of demographic responses to climate change has largely been limited to single species and locations. Here we show that amphibian communities are responsive to climatic variability, using > 500,000 time-series observations for 81 species across 86 North American study areas. The effect of climate on local colonization and persistence probabilities varies among eco-regions and depends on local climate, species life-histories, and taxonomic classification. We found that local species richness is most sensitive to changes in water availability during breeding and changes in …

Crop Pests And Predators Exhibit Inconsistent Responses To Surrounding Landscape Composition, Daniel S. Karp, Rebecca Chaplin-Kramer, Timothy D. Meehan, Emily A. Martin, Fabrice Declerck, Heather Grab, Claudio Gratton, Lauren Hunt, Ashley E. Larsen, Alejandra Martínez-Salinas, Megan E. O’Rourke, Adrien Rusch, Katja Poveda, Mattias Jonsson, Jay A. Rosenheim, Nancy A. Schellhorn, Teja Tscharntke, Stephen D. Wratten, Wei Zhang, Aaron L. Iverson, Lynn S. Adler, Matthias Albrecht, Audrey Alignier, Gina M. Angelella, Muhammad Zubair Anjum, Jacques Avelino, Péter Batáry, Johannes M. Baveco, Felix J. J. A. Bianchi, Klaus Birkhofer, David J. Gonthier

Entomology Faculty Publications

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop …

Horse Y Chromosome Assembly Displays Unique Evolutionary Features And Putative Stallion Fertility Genes, Jan E. Janečka, Brian W. Davis, Sharmila Ghosh, Nandina Paria, Pranab J. Das, Ludovic Orlando, Mikkel Schubert, Martin K. Nielsen, Tom A. E. Stout, Wesley Brashear, Gang Li, Charles D. Johnson, Richard P. Metz, Al Muatasim Al Zadjali, Charles C. Love, Dickson D. Varner, Daniel W. Bellott, William J. Murphy, Bhanu P. Chowdhary, Terje Raudsepp

Veterinary Science Faculty Publications

Dynamic evolutionary processes and complex structure make the Y chromosome among the most diverse and least understood regions in mammalian genomes. Here, we present an annotated assembly of the male specific region of the horse Y chromosome (eMSY), representing the first comprehensive Y assembly in odd-toed ungulates. The eMSY comprises single-copy, equine specific multi-copy, PAR transposed, and novel ampliconic sequence classes. The eMSY gene density approaches that of autosomes with the highest number of retained X–Y gametologs recorded in eutherians, in addition to novel Y-born and transposed genes. Horse, donkey and mule testis RNAseq reveals several candidate genes for stallion …

Advancing Behavioural Genomics By Considering Timescale, Clare C. Rittschof, Kimberly A. Hughes

Entomology Faculty Publications

Animal behavioural traits often covary with gene expression, pointing towards a genomic constraint on organismal responses to environmental cues. This pattern highlights a gap in our understanding of the time course of environmentally responsive gene expression, and moreover, how these dynamics are regulated. Advances in behavioural genomics explore how gene expression dynamics are correlated with behavioural traits that range from stable to highly labile. We consider the idea that certain genomic regulatory mechanisms may predict the timescale of an environmental effect on behaviour. This temporally minded approach could inform both organismal and evolutionary questions ranging from the remediation of early …

Mitochondrial Phylogenomics Of Hemiptera Reveals Adaptive Innovations Driving The Diversification Of True Bugs, Hu Li, John Moeller Leavengood Jr., Eric G. Chapman, Daniel Burkhardt, Fan Song, Pei Jiang, Jinpeng Liu, Xuguo Zhou, Wanzhi Cai

Entomology Faculty Publications

Hemiptera, the largest non-holometabolous order of insects, represents approximately 7% of metazoan diversity. With extraordinary life histories and highly specialized morphological adaptations, hemipterans have exploited diverse habitats and food sources through approximately 300 Myr of evolution. To elucidate the phylogeny and evolutionary history of Hemiptera, we carried out the most comprehensive mitogenomics analysis on the richest taxon sampling to date covering all the suborders and infraorders, including 34 newly sequenced and 94 published mitogenomes. With optimized branch length and sequence heterogeneity, Bayesian analyses using a site-heterogeneous mixture model resolved the higher-level hemipteran phylogeny as (Sternorrhyncha, (Auchenorrhyncha, (Coleorrhyncha, Heteroptera))). Ancestral character …

Life-Shortening Wolbachia Infection Reduces Population Growth Of Aedes Aegypti, Eunho Suh, David R. Mercer, Stephen L. Dobson

Entomology Faculty Publications

Wolbachia bacteria are being introduced into natural populations of vector mosquitoes, with the goal of reducing the transmission of human diseases such as Zika and dengue fever. The successful establishment of Wolbachia infection is largely dependent on the effects of Wolbachia infection to host fitness, but the effects of Wolbachia infection on the individual life-history traits of immature mosquitoes can vary. Here, the effects of life-shortening Wolbachia (wMelPop) on population growth of infected individuals were evaluated by measuring larval survival, developmental time and adult size of Aedes aegypti in intra- (infected or uninfected only) and inter-group (mixed with …

Oviposition Traits Generate Extrinsic Postzygotic Isolation Between Two Pine Sawfly Species, Emily E. Bendall, Kim L. Vertacnik, Catherine R. Linnen

Biology Faculty Publications

Background: Although empirical data indicate that ecological speciation is prevalent in nature, the relative importance of different forms of reproductive isolation and the traits generating reproductive isolation remain unclear. To address these questions, we examined a pair of ecologically divergent pine-sawfly species: while Neodiprion pinetum specializes on a thin-needled pine (Pinus strobus), N. lecontei utilizes thicker-needled pines. We hypothesized that extrinsic postzygotic isolation is generated by oviposition traits. To test this hypothesis, we assayed ovipositor morphology, oviposition behavior, and host-dependent oviposition success in both species and in F1 and backcross females.

Results: Compared to N. lecontei, N. …

Genome Of The Asian Longhorned Beetle (Anoplophora Glabripennis), A Globally Significant Invasive Species, Reveals Key Functional And Evolutionary Innovations At The Beetle-Plant Interface, Duane D. Mckenna, Erin D. Scully, Yannick Pauchet, Kelli Hoover, Roy Kirsch, Scott M. Geib, Robert F. Mitchell, Robert M. Waterhouse, Seung-Joon Ahn, Deanna Arsala, Joshua B. Benoit, Heath Blackmon, Tiffany Bledsoe, Julia H. Bowsher, André Busch, Bernarda Calla, Hsu Chao, Anna K. Childers, Christopher Childers, Dave J. Clarke, Lorna Cohen, Jeffery P. Demuth, Huyen Dinh, Harshavardhan Doddapaneni, Amanda Dolan, Jian J. Duan, Shannon Dugan, Markus Friedrich, Karl M. Glastad, Michael A. D. Goodisman, Stephanie Haddad, Yi Han, Daniel S. T. Hughes, Panagiotis Ioannidis, J. Spencer Johnston, Jeffery W. Jones, Leslie A. Kuhn, David R. Lance, Chien-Yueh Lee, Sandra L. Lee, Han Lin, Jeremy A. Lynch, Armin P. Moczek, Shwetha C. Murali, Donna M. Muzny, David R. Nelson, Subba R. Palli, Kristen A. Panfilio, Dan Pers, Monica F. Poelchau, Honghu Quan, Jiaxin Qu, Ann M. Ray, Joseph P. Rinehart, Hugh M. Robertson, Richard Roehrdanz, Andrew J. Rosendale, Seunggwan Shin, Christian Silva, Alex S. Torson, Iris M. Vargas Jentzsch, John H. Werren, Kim C. Worley, George Yocum, Evgeny M. Zdobnov, Richard A. Gibbs, Stephen Richards

Entomology Faculty Publications

Background: Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved in digestion of woody plant tissues or detoxification of plant allelochemicals were undertaken with the genomes of 14 additional insects, including the newly sequenced emerald ash borer and bull-headed dung beetle.

Results: …

The Interrelationships Of Placental Mammals And The Limits Of Phylogenetic Inference, James E. Tarver, Mario Dos Reis, Siavash Mirarab, Raymond J. J. Moran, Sean Parker, Joseph E. O'Reilly, Benjamin L. King, Mary J. O'Connell, Robert J. Asher, Tandy Warnow, Kevin J. Peterson, Philip C.J. Donoghue, Davide Pisani

Dartmouth Scholarship

Placental mammals comprise three principal clades: Afrotheria (e.g., elephants and tenrecs), Xenarthra (e.g., armadillos and sloths), and Boreoeutheria (all other placental mammals), the relationships among which are the subject of controversy and a touchstone for debate on the limits of phylogenetic inference. Previous analyses have found support for all three hypotheses, leading some to conclude that this phylogenetic problem might be impossible to resolve due to the compounded effects of incomplete lineage sorting (ILS) and a rapid radiation. Here we show, using a genome scale nucleotide data set, microRNAs, and the reanalysis of the three largest previously published amino acid …

Sex Allocation And The Emergence Of Helping In Cooperatively Breeding Species., Josh D Dunn, Teodora Vujicic, Geoff Wild

Applied Mathematics Publications

In cooperative breeding systems individuals invest in the reproductive success of others. In this paper, we study the emergence of cooperative breeding systems in which reproductively active breeders receive investment from reproductively non-active helpers. Our goal is to understand how the division of an investment between male and female components of breeder fitness (i.e. the helper sex-allocation strategy) influences the emergence of cooperative breeding itself. Using mathematical models, we arrive at expressions for the inclusive-fitness advantage of helpful behaviour that generalize previous work. These expressions assume an ecologically stable environment, and that breeders make evolutionarily stable sex-allocation decisions. We find …

Social Communication Of Predator-Induced Changes In Drosophila Behavior And Germ Line Physiology, Balint Z. Kacsoh, Julianna Bozler, Mani Ramaswami, Giovanni Bosco

Dartmouth Scholarship

Behavioral adaptation to environmental threats and subsequent social transmission of adaptive behavior has evolutionary implications. In Drosophila, exposure to parasitoid wasps leads to a sharp decline in oviposition. We show that exposure to predator elicits both an acute and learned oviposition depression, mediated through the visual system. However, long-term persistence of oviposition depression after predator removal requires neuronal signaling functions, a functional mushroom body, and neurally driven apoptosis of oocytes through effector caspases. Strikingly, wasp-exposed flies (teachers) can transmit egg-retention behavior and trigger ovarian apoptosis in naive, unexposed flies (students). Acquisition and behavioral execution of this socially learned behavior …

Collapse Of An Ecological Network In Ancient Egypt, Justin Yeakel, Mathias Pires, Lars Rudolf, Nathaniel Dominy

Dartmouth Scholarship

The dynamics of ecosystem collapse are fundamental to determining how and why biological communities change through time, as well as the potential effects of extinctions on ecosystems. Here, we integrate depictions of mammals from Egyptian antiquity with direct lines of paleontological and archeological evidence to infer local extinctions and community dynamics over a 6,000-y span. The unprecedented temporal resolution of this dataset enables examination of how the tandem effects of human population growth and climate change can disrupt mammalian communities. We show that the extinctions of mammals in Egypt were nonrandom and that destabilizing changes in community composition coincided with …

Natural Selection On Thermal Performance In A Novel Thermal Environment, Michael L. Logan, Robert M. Cox, Ryan Calsbeek

Dartmouth Scholarship

Tropical ectotherms are thought to be especially vulnerable to climate change because they are adapted to relatively stable temperature regimes, such that even small increases in environmental temperature may lead to large decreases in physiological performance. One way in which tropical organisms may mitigate the detrimental effects of warming is through evolutionary change in thermal physiology. The speed and magnitude of this response depend, in part, on the strength of climate-driven selection. However, many ectotherms use behavioral adjustments to maintain preferred body temperatures in the face of environmental variation. These behaviors may shelter individuals from natural selection, preventing evolutionary adaptation …

Population And Demographic Structure Of Ixodes Scapularis Say In The Eastern United States., Joyce M. Sakamoto, Jerome Goddard, Jason L. Rasgon

College of Agriculture & Life Sciences Publications and Scholarship

INTRODUCTION: The most significant vector of tick-borne pathogens in the United States is Ixodes scapularis Say (the blacklegged tick). Previous studies have identified significant genetic, behavioral and morphological differences between northern vs. southern populations of this tick. Because tick-borne pathogens are dependent on their vectors for transmission, a baseline understanding of the vector population structure is crucial to determining the risks and epidemiology of pathogen transmission. METHODS: We investigated population genetic variation of I. scapularis populations in the eastern United States using a multilocus approach. We sequenced and analyzed the mitochondrial COI and 16S genes and three nuclear genes (serpin2, …

Divergent Transcriptional Responses To Low Temperature Among Populations Of Alpine And Lowland Species Of New Zealand Stick Insects (Micrarchus)., Luke T Dunning, Alice B Dennis, Brent J Sinclair, Richard D Newcomb, Thomas R Buckley

Biology Publications

In widespread and genetically structured populations, temperature variation may lead to among-population differentiation of thermal biology. The New Zealand stick insect genus Micrarchus contains four species that inhabit different thermal environments, two of which are geographically widespread. RNA-Seq and quantitative PCR were used to investigate the transcriptional responses to cold shock among lowland and alpine species to identify cold-responsive transcripts that differ between the species and to determine whether there is intraspecific geographical variation in gene expression. We also used mitochondrial DNA, nuclear 28S ribosomal DNA and transcriptome-wide SNPs to determine phylogeographic structure and the potential for differences in genetic …

Primate Energy Eexpenditure And Life History, Herman Pontzer, David A. Raichlen, Adam D. Gordon, Kara K. Schroepfer-Walker, Brian Hare, Matthew C. O’Neill, Kathleen M. Muldoon

Dartmouth Scholarship

Humans and other primates are distinct among placental mammals in having exceptionally slow rates of growth, reproduction, and aging. Primates’ slow life history schedules are generally thought to reflect an evolved strategy of allocating energy away from growth and reproduction and toward somatic investment, particularly to the development and maintenance of large brains. Here we examine an alternative explanation: that primates’ slow life histories reflect low total energy expenditure (TEE) (kilocalories per day) relative to other placental mammals. We compared doubly labeled water measurements of TEE among 17 primate species with similar measures for other placental mammals. We found that …

Colour And Odour Drive Fruit Selection And Seed Dispersal By Mouse Lemurs, Kim Valenta, Ryan J. Burke, Sarah A. Styler, Derek A. Jackson, Amanda D. Melin, Shawn M. Lehman

Dartmouth Scholarship

Animals and fruiting plants are involved in a complex set of interactions, with animals relying on fruiting trees as food resources, and fruiting trees relying on animals for seed dispersal. This interdependence shapes fruit signals such as colour and odour, to increase fruit detectability, and animal sensory systems, such as colour vision and olfaction to facilitate food identification and selection. Despite the ecological and evolutionary importance of plant-animal interactions for shaping animal sensory adaptations and plant characteristics, the details of the relationship are poorly understood. Here we examine the role of fruit chromaticity, luminance and odour on seed dispersal by …

Cold Tolerance Of The Eastern Subterranean Termite, Reticulitermes Flavipes (Isoptera: Rhinotermitidae), In Ontario., Matthew W. Clarke, Graham J. Thompson, Brent J Sinclair

Biology Publications

We characterized the cold tolerance of natural populations of the Eastern subterranean termite (Reticulitermes flavipes (Kollar) [Isoptera, Rhinotermitidae]) in southwestern Ontario, Canada. We measured cold tolerance in workers from six colonies of termites established from Pelee Island in Lake Erie, and Point Pelee National Park. The mean critical thermal minimum, at which termites entered chill coma, ranged from 8.1 to 5.7°C. Mean supercooling points (SCP, the temperature at which individuals freeze) ranged from -4 to -4.6°C, and did not differ significantly between colonies, nor was SCP dependent on body size. Individuals survived brief exposure to low temperatures, as long as …

A Comprehensive And Integrative Reconstruction Of Evolutionary History For Anomura (Crustacea: Decapoda)., Heather D Bracken-Grissom, Maren E Cannon, Patricia Cabezas, Rodney M Feldmann, Carrie E Schweitzer, Shane T Ahyong, Darryl L Felder, Rafael Lemaitre, Keith A Crandall

Computational Biology Institute

BACKGROUND: The infraorder Anomura has long captivated the attention of evolutionary biologists due to its impressive morphological diversity and ecological adaptations. To date, 2500 extant species have been described but phylogenetic relationships at high taxonomic levels remain unresolved. Here, we reconstruct the evolutionary history-phylogeny, divergence times, character evolution and diversification-of this speciose clade. For this purpose, we sequenced two mitochondrial (16S and 12S) and three nuclear (H3, 18S and 28S) markers for 19 of the 20 extant families, using traditional Sanger and next-generation 454 sequencing methods. Molecular data were combined with 156 morphological characters in order to estimate the largest …

Tree Climbing And Human Evolution, Vivek V. Venkataraman, Thomas S. Kraft, Nathaniel J. Dominy

Dartmouth Scholarship

Paleoanthropologists have long argued—often contentiously—about the climbing abilities of early hominins and whether a foot adapted to terrestrial bipedalism constrained regular access to trees. However, some modern humans climb tall trees routinely in pursuit of honey, fruit, and game, often without the aid of tools or support systems. Mortality and morbidity associated with facultative arboreality is expected to favor behaviors and anatomies that facilitate safe and efficient climbing. Here we show that Twa hunter–gatherers use extraordinary ankle dorsiflexion (>45°) during climbing, similar to the degree observed in wild chimpanzees. Although we did not detect a skeletal signature of dorsiflexion …

Aspm And The Evolution Of Cerebral Cortical Size In A Community Of New World Monkeys, Fernando A. Villanea, George H. Perry, Gustavo A. Gutiérrez-Espeleta, Nathaniel J. Dominy

Dartmouth Scholarship

The ASPM (abnormal spindle-like microcephaly associated) gene has been proposed as a major determinant of cerebral cortical size among primates, including humans. Yet the specific functions of ASPM and its connection to human intelligence remain controversial. This debate is limited in part by a taxonomic focus on Old World monkeys and apes. Here we expand the comparative context of ASPM sequence analyses with a study of New World monkeys, a radiation of primates in which enlarged brain size has evolved in parallel in spider monkeys (genus Ateles) and capuchins (genus Cebus). The primate community of Costa Rica is perhaps a …

Two Boundaries Separate Borrelia Burgdorferi Populations In North America, Gabriele Margos, Jean I. Tsao, Santiago Castillo-Ramirez, Yvette A. Girard, Anne G. Hoen

Dartmouth Scholarship

Understanding the spread of infectious diseases is crucial for implementing effective control measures. For this, it is important to obtain information on the contemporary population structure of a disease agent and to infer the evolutionary processes that may have shaped it. Here, we investigate on a continental scale the population structure of Borrelia burgdorferi, the causative agent of Lyme borreliosis (LB), a tick-borne disease, in North America. We test the hypothesis that the observed d population structure is congruent with recent population expansions and that these were preceded by bottlenecks mostly likely caused by the near extirpation in the 1900s …

Fecal Near Infrared Spectroscopy To Discriminate Physiological Status In Giant Pandas., Erin E. Wiedower, Andrew J. Kouba, Carrie K. Vance, Rachel L. Hansen, Jerry W. Stuth, Douglas R. Tolleson

College of Agriculture & Life Sciences Publications and Scholarship

Giant panda (Ailuropoda melanoleuca) monitoring and research often require accurate estimates of population size and density. However, obtaining these estimates has been challenging. Innovative technologies, such as fecal near infrared reflectance spectroscopy (FNIRS), may be used to differentiate between sex, age class, and reproductive status as has been shown for several other species. The objective of this study was to determine if FNIRS could be similarly used for giant panda physiological discriminations. Based on samples from captive animals in four U.S. zoos, FNIRS calibrations correctly identified 78% of samples from adult males, 81% from adult females, 85% from adults, 89% …

Wild Justice Redux: What We Know About Social Justice In Animals And Why It Matters, Jessica Pierce, Marc Bekoff

Ethology Collection

Social justice in animals is beginning to attract interest in a broad range of academic disciplines. Justice is an important area of study because it may help explain social dynamics among individuals living in tightly- knit groups, as well as social interactions among individuals who only occasionally meet. In this paper, we provide an overview of what is currently known about social justice in animals and offer an agenda for further research. We provide working definitions of key terms, outline some central research questions, and explore some of the challenges of studying social justice in animals, as well as the …

Mapping Migratory Bird Prevalence Using Remote Sensing Data Fusion, Anu Swatantran, Ralph Dubayah, Scott Goetz, Michelle Hofton, Matthew G. Betts, Mindy Sun, Marc Simard, Richard Holmes

Dartmouth Scholarship

Background: Improved maps of species distributions are important for effective management of wildlife under increasing anthropogenic pressures. Recent advances in lidar and radar remote sensing have shown considerable potential for mapping forest structure and habitat characteristics across landscapes. However, their relative efficacies and integrated use in habitat mapping remain largely unexplored. We evaluated the use of lidar, radar and multispectral remote sensing data in predicting multi-year bird detections or prevalence for 8 migratory songbird species in the unfragmented temperate deciduous forests of New Hampshire, USA.

Methodology and Principal Findings: A set of 104 predictor variables describing vegetation vertical structure and …

Predator Mediated Selection And The Impact Of Developmental Stage On Viability In Wood Frog Tadpoles (Rana Sylvatica), Ryan Calsbeek, Shawn Kuchta

Dartmouth Scholarship

Complex life histories require adaptation of a single organism for multiple ecological niches. Transitions between life stages, however, may expose individuals to an increased risk of mortality, as the process of metamorphosis typically includes developmental stages that function relatively poorly in both the pre- and post-metamorphic habitat. We studied predator-mediated selection on tadpoles of the wood frog, Rana sylvatica, to identify this hypothesized period of differential predation risk and estimate its ontogenetic onset. We reared tadpoles in replicated mesocosms in the presence of the larval odonate Anax junius, a known tadpole predator.

Episodic Radiations In The Fly Tree Of Life, Brian M. Wiegmann, Michelle D. Trautwein, Isaac S. Winkler, Norman B. Barr, Jung-Wook Kim, Christine Lambkin, Matthew Bertone, Brian Cassel, Keith Bayless, Alysha Heimberg

Dartmouth Scholarship

Flies are one of four superradiations of insects (along with beetles, wasps, and moths) that account for the majority of animal life on Earth. Diptera includes species known for their ubiquity (Musca domestica house fly), their role as pests (Anopheles gambiae malaria mosquito), and their value as model organisms across the biological sciences (Drosophila melanogaster). A resolved phylogeny for flies provides a framework for genomic, developmental, and evolutionary studies by facilitating comparisons across model organisms, yet recent research has suggested that fly relationships have been obscured by multiple episodes of rapid diversification. We provide a phylogenomic …