Life Sciences Commons^™

Rewiring Of Aminoacyl-Trna Synthetase Localization And Interactions In Plants With Extensive Mitochondrial Trna Gene Loss, Jessica M. Warren, Amanda K. Broz, Ana Martinez-Hottovy, Christian Elowsky, Alan C. Christensen, Daniel B. Sloan

School of Biological Sciences: Faculty Publications

The number of tRNAs encoded in plant mitochondrial genomes varies considerably. Ongoing loss of bacterial-like mitochondrial tRNA genes in many lineages necessitates the import of nuclear-encoded counterparts that share little sequence similarity. Because tRNAs are involved in highly specific molecular interactions, this replacement process raises questions about the identity and trafficking of enzymes necessary for the maturation and function of newly imported tRNAs. In particular, the aminoacyl-tRNA synthetases (aaRSs) that charge tRNAs are usually divided into distinct classes that specialize on either organellar (mitochondrial and plastid) or nuclear-encoded (cytosolic) tRNAs. Here, we investigate the evolution of aaRS subcellular localization in …

Essential And Recurrent Roles For Hairpin Rnas In Silencing De Novo Sex Chromosome Conflict In Drosophila Simulans, Jeffrey Vedanayagam, Marion Herbette, Holly Mudgett, Ching-Jung Lin, Chun- Ming Lai, Caitlin Mcdonough-Goldstein, Stephen Dorus, Benjamin Loppin, Colin D. Meiklejohn, Raphaëlle Dubruille, Eric C. Lai

School of Biological Sciences: Faculty Publications

Meiotic drive loci distort the normally equal segregation of alleles, which benefits their own transmission even in the face of severe fitness costs to their host organism. However, relatively little is known about the molecular identity of meiotic drivers, their strategies of action, and mechanisms that can suppress their activity. Here, we present data from the fruitfly Drosophila simulans that address these questions. We show that a family of de novo, protamine- derived X-linked selfish genes (the Dox gene family) is silenced by a pair of newly emerged hairpin RNA (hpRNA) small interfering RNA (siRNA)-class loci, Nmy and Tmy. …

Characterization Of A Novel Polyextremotolerant Fungus, Exophiala Viscosa, With Insights Into Its Melanin Regulation And Ecological Niche, Erin C. Carr, Quin Barton, Sarah Grambo, Mitchell Sullivan, Cecile M. Renfro, Alan Kuo, Jasmyn Pangilinan, Anna Lipzen, Keykhosrow Keymanesh, Emily Savage, Kerrie Barry, Igor V. Grigoriev, Wayne R. Riekhof, Steven D. Harris

School of Biological Sciences: Faculty Publications

Black yeasts are polyextremotolerant fungi that contain high amounts of melanin in their cell wall and maintain a primar yeast form. These fungi grow in xeric, nutrient depletes environments which implies that they require highly flexible metabolisms and have been suggested to contain the ability to form lichen-like mutualisms with nearby algae and bacteria. However, the exact ecological niche and interactions between these fungi and their surrounding community are not well understood. We have isolated 2 novel black yeasts from the genus Exophiala that were recovered from dryland biological soil crusts. Despite notable differences in colony and cellular morphology, both …

A Standard Protocol To Report Discrete Stage-Structured Demographic Information, Samuel J. L. Gascoigne, Simon Rolph, Daisy Sankey, Nagalakshmi Nidadavolu, Adrian S. Stell Pičman, Christina M. Hernández, Matthew E. R. Philpott, Aiyla Salam, Connor Bernard, Erola Fenollosa, Young Jun Lee, Jessica Mclean, Shathuki Hetti Achchige Perera, Oliver G. Spacey, Maja Kajin, Anna C. Vinton, C. Ruth Archer, Jean H. Burns, Danielle L. Buss, Hal Caswell, Judy P. Che-Castaldo, Dylan Z. Childs, Pol Capdevila, Aldo Compagnoni, Elizabeth Crone, Thomas H. G. Ezard, Dave Hodgson, Tiffany M. Knight, Owen R. Jones, Eelke Jongejans, Jenni Mcdonald, Brigitte Tenhumberg, Chelsea C. Thomas, Andrew J. Tyre, Satu Ramula, Iain Stott, Raymond L. Tremblay, Phil Wilson, James James Vaupel, Roberto Salguero-Gómez

School of Biological Sciences: Faculty Publications

1. Stage-based demographic methods, such as matrix population models (MPMs), are powerful tools used to address a broad range of fundamental questions in ecology, evolutionary biology and conservation science. Accordingly, MPMs now exist for over 3000 species worldwide. These data are being digitised as an ongoing process and periodically released into two large open-access online repositories: the COMPADRE Plant Matrix Database and the COMADRE Animal Matrix Database. During the last decade, data archiving and curation of COMPADRE and COMADRE, and subsequent comparative research, have revealed pronounced variation in how MPMs are parameterized and reported.

2. Here, we summarise current issues related to …

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The Synergistic Response Of Primary Production In Grasslands To Combined Nitrogen And Phosphorus Addition Is Caused By Increased Nutrient Uptake And Retention, Eduardo Vázquez, Elizabeth T. Borer, Miguel N. Bugalho, Maria C. Caldeira, Rebecca L. Mcculley, Anita C. Risch, Eric W. Seabloom, George R. Wheeler, Marie Spohn

School of Biological Sciences: Faculty Publications

Background and aims A synergistic response of aboveground plant biomass production to combined nitrogen (N) and phosphorus (P) addition has been observed in many ecosystems, but the underlying mechanisms and their relative importance are not well known. We aimed at evaluating several mechanisms that could potentially cause the synergistic growth response, such as changes in plant biomass allocation, increased N and P uptake by plants, and enhanced ecosystem nutrient retention.

Methods We studied five grasslands located in Europe and the USA that are subjected to an element addition experiment composed of four treatments: control (no element addition), N addition, …

Ecological Boundaries And Constraints On Viable Eco-Evolutionary Pathways, Kyle E. Coblentz, John P. Delong

School of Biological Sciences: Faculty Publications

Evolutionary dynamics are subject to constraints ranging from limitations on what is physically possible to limitations on the pathways that evolution can take. One set of evolutionary constraints, known as ‘demographic constraints’, constrain what can occur evolutionarily due to the demographic or dynamical consequences of evolution leading to conditions that make populations susceptible to extinction. These demographic constraints can limit the strength of selection or the rates of environmental change populations can experience while remaining extant and the trait values a population can express. Here we further hypothesize that the population demographic and dynamic consequences of evolution also can constrain …

Lessons From Chloroviruses: The Complex And Diverse Roles Of Viruses In Food Webs, John Delong, James L. Van Etten, David Dunigan

School of Biological Sciences: Faculty Publications

Viruses can have large effects on the ecological communities in which they occur. Much of this impact comes from the mortality of host cells, which simultaneously alters microbial community composition and causes the release of matter that can be used by other organisms. However, recent studies indicate that viruses may be even more deeply integrated into the functioning of ecological communities than their effect on nutrient cycling suggests. In particular, chloroviruses, which infect chlorella-like green algae that typically occur as endosymbionts, participate in three types of interactions with other species. Chlororviruses (i) can lure ciliates from a distance, using them …

Examining Whether And How Instructional Coordination Occurs Within Introductory Undergraduate Stem Courses, Brian Couch, Luanna B. Prevost, Marilyne Stains, Blake Whitt, Ariel E. Marcy, Naneh Apkarian, Melissa H. Dancy, Charles Henderson, Estrella Johnson, Jeffrey R. Raker, Brandon J. Yik, Brittnee Earl, Susan E. Shadle, John Skvoretz, John P. Ziker

School of Biological Sciences: Faculty Publications

Instructors’ interactions can foster knowledge sharing around teaching and the use of research-based instructional strategies (RBIS). Coordinated teaching presents an impetus for instructors’ interactions and creates opportunities for instructional improvement but also potentially limits an instructor’s autonomy. In this study, we sought to characterize the extent of coordination present in introductory undergraduate courses and to understand how departments and instructors implement and experience course coordination. We examined survey data from 3,641 chemistry, mathematics, and physics instructors at three institution types and conducted follow-up interviews with a subset of 24 survey respondents to determine what types of coordination existed, what factors …

Upregulation Of Cell Surface Glycoproteins In Correlation With Kshv Lana In The Kaposi Sarcoma Tumor Microenvironment, Sara R. Privatt, Owen Ngalamika, Jianshui Zhang, Qinsheng Li, Charles Wood, John T. West

School of Biological Sciences: Faculty Publications

HIV-associated epidemic Kaposi sarcoma (EpKS) remains one of the most prevalent cancers in sub-Saharan Africa despite the widespread uptake of anti-retroviral therapy and HIV-1 suppression. In an effort to define potential therapeutic targets against KS tumors, we analyzed previously published KS bulk tumor transcriptomics to identify cell surface biomarkers. In addition to upregulated gene expression (>6-fold) in the EpKS tumor microenvironment, biomarkers were selected for correlation with KSHV latency-associated nuclear antigen (LANA) expression. The cell surface glycoprotein genes identified were KDR, FLT4, ADAM12, UNC5A, ZP2, and OX40, as well as the endothelial lineage determinants Prox-1 and CD34. Each protein …

Small Rnas >26 Nt In Length Associate With Ago1 And Are Upregulated By Nutrient Deprivation In The Alga Chlamydomonas, Yingshan Li, Eun-Jeong Kim, Adam Voshall, Etsuko Moriyama, Heriberto D. Cerutti

School of Biological Sciences: Faculty Publications

Small RNAs (sRNAs) associate with ARGONAUTE (AGO) proteins forming effector complexes with key roles in gene regulation and defense responses against molecular parasites. In multicellular eukaryotes, extensive duplication and diversification of RNA interference (RNAi) components have resulted in intricate pathways for epigenetic control of gene expression. The unicellular alga Chlamydomonas reinhardtii also has a complex RNAi machinery, including 3 AGOs and 3 DICER-like proteins. However, little is known about the biogenesis and function of most endogenous sRNAs. We demonstrate here that Chlamydomonas contains uncommonly long (>26 nt) sRNAs that associate preferentially with AGO1. Somewhat reminiscent of animal PIWI-interacting RNAs, …

Dwarfism And Gigantism Drive Human-Mediated Extinctions On Islands, Roberto Rozzi, Mark V. Lomolino, Alexandra A.E. Van Der Geer, Daniele Silvestro, S. Kathleen Lyons, Pere Bover, Josep A. Alcover, Ana Benítez-López, Cheng-Hsiu Tsai, Masaki Fujita, Mugino O. Kubo, Janinie Ochoa, Matthew E, Scarborough, Samuel T. Turvey, Alexander Zizka, Jonathan M. Chase

School of Biological Sciences: Faculty Publications

Islands have long been recognized as distinctive evolutionary arenas leading to morphologically divergent species, such as dwarfs and giants. We assessed how body size evolution in island mammals may have exacerbated their vulnerability, as well as how human arrival has contributed to their past and ongoing extinctions, by integrating data on 1231 extant and 350 extinct species from islands and paleo islands worldwide spanning the past 23 million years. We found that the likelihood of extinction and of endangerment are highest in the most extreme island dwarfs and giants. Extinction risk of insular mammals was compounded by the arrival of …

Ecological Boundaries And Constraints On Viable Eco-Evolutionary Pathways, Kyle E. Coblentz, John P. Delong

School of Biological Sciences: Faculty Publications

Evolutionary dynamics are subject to constraints ranging from limitations on what is physically possible to limitations on the pathways that evolution can take. One set of evolutionary constraints, known as ‘demographic constraints’, constrain what can occur evolutionarily due to the demographic or dynamical consequences of evolution leading to conditions that make populations susceptible to extinction. These demographic constraints can limit the strength of selection or the rates of environmental change populations can experience while remaining extant and the trait values a population can express. Here we further hypothesize that the population demographic and dynamic consequences of evolution also can constrain …

How Administration Stakes And Settings Affect Student Behavior And Performance On A Biology Concept Assessment, Crystal Uminski, Joanna K. Hubbard, Brian Couch

School of Biological Sciences: Faculty Publications

Biology instructors use concept assessments in their courses to gauge student understanding of important disciplinary ideas. Instructors can choose to administer concept assessments based on participation (i.e., lower stakes) or the correctness of responses (i.e., higher stakes), and students can complete the assessment in an in-class or out-of-class setting. Different administration conditions may affect how students engage with and perform on concept assessments, thus influencing how instructors should interpret the resulting scores. Building on a validity framework, we collected data from 1578 undergraduate students over 5 years under five different administration conditions. We did not find significant differences in scores …

Plant Species’ Capacity For Range Shifts At The Habitat And Geographic Scales: A Trade-Off-Based Framework, Bailey H. Mcnichol, Sabrina E. Russo

School of Biological Sciences: Faculty Publications

Climate change is causing rapid shifts in the abiotic and biotic environmental conditions experienced by plant populations, but we lack generalizable frameworks for predicting the consequences for species. These changes may cause individuals to become poorly matched to their environments, potentially inducing shifts in the distributions of populations and altering species’ habitat and geographic ranges. We present a trade-off-based framework for understanding and predicting whether plant species may undergo range shifts, based on ecological strategies defined by functional trait variation. We define a species’ capacity for undergoing range shifts as the product of its colonization ability and the ability to …

Natural Variation In Host Feeding Behaviors Impacts Host Disease And Pathogen Transmission Potential, Alaina C. Pfenning-Butterworth, Rachel E. Vetter, Jessica L. Hite

School of Biological Sciences: Faculty Publications

Animals ranging from mosquitoes to humans often vary their feeding behavior when infected or merely exposed to pathogens. These so-called “sickness behaviors” are part of the innate immune response with many consequences, including avoiding orally transmitted pathogens. Fully understanding the role of this ubiquitous behavior in host defense and pathogen evolution requires a quantitative account of its impact on host and pathogen fitness across environmentally relevant contexts. Here, we use a zooplankton host and fungal pathogen as a case study to ask if infection-mediated feeding behaviors vary across pathogen exposure levels and natural genetic variation in susceptibility to infection. Then, …

Intraguild Predation Is Increased In Areas Of Low Prey Diversity In A Generalist Predator Community, Stella F. Uiterwaal, Amber J. Squires, Bennett A. Grappone, Brian Dillard, Ariadne Castaneda, Sora L. Kim, John P. Delong

School of Biological Sciences: Faculty Publications

1. Niche differentiation and intraguild predation (IGP) can allow ecologically similar species to coexist, although it is unclear which coexistence mechanism predominates in consumer communities. Until now, a limited ability to quantify diets from metabarcoding data has precluded the use of sequencing data to determine the relative importance of these mechanisms.

2. Here, we pair a recent metabarcoding quantification approach with stable isotope analysis to examine diet composition in a wolf spider community.

3. We compare the prevalence of resource partitioning and IGP in these spiders and test whether factors that influence foraging performance, including individual identity, morphology, prey community and environmental conditions, …

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Depletion Of Hiv Reservoir By Activation Of Isr Signaling In Resting Cd4+T Cells, Dajiang Li, Lilly M. Wong, Yuyang Tang, Brigitte Allard, Katherine S. James, George R. Thompson, Satya Dandekar, Edward P. Browne, Qingsheng Li, Jeremy M. Simon, Nancie M. Archin, David M. Margolis, Guochun Jiang

School of Biological Sciences: Faculty Publications

HIV reservoirs are extremely stable and pose a tremendous challenge to clear HIV infection. Here, we demonstrate that activation of ISR/ATF4 signaling reverses HIV latency, which also selectively eliminates HIV+ cells in primary CD4⁺T cell model of latency without effect on HIV-negative CD⁴⁺T cells. The reduction of HIV+ cells is associated with apoptosis enhancement, but surprisingly is largely seen in HIV-infected cells in which gag-pol RNA transcripts are detected in HIV RNA-induced ATF4/IFIT signaling. In resting CD4⁺ (rCD4⁺) T cells isolated from people living with HIV on antiretroviral therapy, induction of ISR/ATF4 signaling …

Seasonal Plasticity In Morphology And Metabolism Differs Between Migratory North American And Resident Costa Rican Monarch Butterflies, Ayşe Tenger-Trolander, Cole R. Julick, Wei Lu, Delbert André Green, Kristi L. Montooth, Marcus R. Kronforst

School of Biological Sciences: Faculty Publications

Environmental heterogeneity in temperate latitudes is expected to maintain seasonally plastic life-history strategies that include the tuning of morphologies and metabolism that support overwintering. For species that have expanded their ranges into tropical latitudes, it is unclear the extent to which the capacity for plasticity will be maintained or will erode with disuse. The migratory generations of the North American (NA) monarch butterfly Danaus plexippus lead distinctly different lives from their summer generation NA parents and their tropical descendants living in Costa Rica (CR). NA migratory monarchs postpone reproduction, travel thousands of kilometers south to overwinter in Mexico, and subsist …

Seasonal Plasticity In Morphology And Metabolism Differs Between Migratory North American And Resident Costa Rican Monarch Butterflies, Ayşe Tenger-Trolander, Cole R. Julick, Wei Lu, Delbert André Green, Kristi L. Montooth, Marcus R. Kronforst

School of Biological Sciences: Faculty Publications

Environmental heterogeneity in temperate latitudes is expected to maintain seasonally plastic life-history strategies that include the tuning of morphologies and metabolism that support overwintering. For species that have expanded their ranges into tropical latitudes, it is unclear the extent to which the capacity for plasticity will be maintained or will erode with disuse. The migratory generations of the North American (NA) monarch butterfly Danaus plexippus lead distinctly different lives from their summer generation NA parents and their tropical descendants living in Costa Rica (CR). NA migratory monarchs postpone reproduction, travel thousands of kilometers south to overwinter in Mexico, and subsist …

Evolution And Molecular Basis Of A Novel Allosteric Property Of Crocodilian Hemoglobin, Chandrasekhar Natarajan, Anthony V. Signore, Naim M. Bautista, Federico G. Hoffmann, Jeremy R.H. Tame, Angela Fago, Jay F. Storz

School of Biological Sciences: Faculty Publications

The extraordinary breath-hold diving capacity of crocodilians has been ascribed to a unique mode of allosterically regulating hemoglobin (Hb)-oxygenation in circulating red blood cells. We investigated the origin and mechanistic basis of this novel biochemical phenomenon by performing directed mutagenesis experiments on resurrected ancestral Hbs. Comparisons of Hb function between the common ancestor of archosaurs (the group that includes crocodilians and birds) and the last common ancestor of modern crocodilians revealed that regulation of Hb-O₂ affinity via allosteric binding of bicarbonate ions represents a croc-specific innovation that evolved in combination with the loss of allosteric regulation by ATP binding. …

Temperature Fluctuation Alters Optimal Predator Community Composition For Anticipated Biological Control, Amanda N. Laubmeier, Nusrat Tabassum, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Alongside pesticides and specialist predators, natural communities of generalist beetle and spider predators play an important role in suppressing agricultural pests. However, the predation pressure of natural communities can be unpredictable. Overall predation pressure is influenced by a dense network of potential intraguild interactions, which are further shaped by species traits and environmental factors. Understanding how these different influences combine to impact pest control is especially important in the context of changing global temperatures. Recent empirical studies have demonstrated that the foraging behavior of arthropod predators is influenced by an interaction between temperature and predator body size. To explore the …

The Association Of Blood Ctdna Levels To Mutations Of Marker Genes In Colorectal Cancer, Fei Bai, Qian Du, Qingliang Zou, Lin Xu, Wei Dong, Xinlin Lv, Xiaorong Han, Huijun Zhou, Chi Zhang, Tao Lu

School of Biological Sciences: Faculty Publications

Background: Colorectal cancer (CRC) is a deadly and commonly diagnosed cancer. Cell‐free circulating tumor DNAs (ctDNA) have been used in the diagnosis and treatment of CRC, but there are open questions about the relationship between ctDNAs and CRC. Although mutations of genes detected by ctDNA in CRC have been studied, the quantitative relationship between ctDNA mutations and ctDNA concentration has not been addressed.

Aims: We hypothesized that there was an association between mutations of genes identified in ctDNAs and ctDNA concentration. His study examined this association in a population of CRC patients.

Methods: In 85 CRC patients, …

Stochasticity Directs Adaptive Evolution Toward Nonequilibrium Evolutionary Attractors, John Delong, Clayton E. Cressler

School of Biological Sciences: Faculty Publications

Stochastic processes such as genetic drift may hinder adaptation, but the effect of such stochasticity on evolution via its effect on ecological dynamics is poorly understood. Here we evaluate patterns of adaptation in a population subject to variation in demographic stochasticity. We show that stochasticity can alter population dynamics and lead to evolutionary outcomes that are not predicted by classic eco-evolutionary modeling approaches. We also show, however, that these outcomes are governed by nonequilibrium evolutionary attractors— these are maxima in lifetime reproductive success when stochasticity keeps the ecological system away from the deterministic equilibrium. These NEEAs alter the path of …

Metamorphosis Imposes Variable Constraints On Genome Expansion Through Effects On Development, R. Lockridge Mueller,, Clayton E. Cressler, R S. Schwartz, R A. Chong, M. Butler

School of Biological Sciences: Faculty Publications

Genome size varies ∼100,000-fold across eukaryotes and has long been hypothesized to be influenced by meta- morphosis in animals. Transposable element accumulation has been identified as a major driver of increase, but the nature of constraints limiting the size of genomes has remained unclear, even as traits such as cell size and rate of development co-vary strongly with genome size. Salamanders, which possess diverse metamorphic and non-metamorphic life histories, join the lung- fish in having the largest vertebrate genomes—3 to 40 times that of humans—as well as the largest range of variation in genome size. We tested 13 biologically-inspired hypotheses …

Ecological Boundaries And Constraints On Viable Eco-Evolutionary Pathways [Pre-Print], Kyle E. Coblentz, John Delong

School of Biological Sciences: Faculty Publications

Evolutionary dynamics are subject to constraints ranging from limitations on what is physically possible to limitations on the pathways that evolution can take. One set of evolutionary constraints, known as ‘demographic constraints’, constrain what can occur evolutionarily due to the population demographic or population dynamical consequences of evolution leading to conditions that make populations susceptible to extinction. These demographic constraints can limit the strength of selection or rates of environmental change populations can experience while remaining extant and the trait values a population can express. Here we further hypothesize that the population demographic and population dynamical consequences of evolution also …

Modelling Pollinator And Nonpollinator Selection On Flower Colour Variation, Brigitte Tenhumberg, Agnes S. Dellinger, Stacey D. Smith

School of Biological Sciences: Faculty Publications

1. Flower colour variation is ubiquitous within and between populations, which is why it has long been a focal point for studies of natural selection. This body of work has uncovered a wide range of selective agents, including pollinators, herbivores, and various abiotic factors. Nevertheless, we lack an integrative framework for predicting the phenotypic outcome in terms of floral pigmentation when these forces act collectively and often in opposition. 2. We here present such a framework through a model that incorporates selection on pigmentation at the vegetative phase (i.e., through survival to reproduction) and at the flowering phase (i.e., on …

Intraguild Predation Is Increased In Areas Of Low Prey Diversity In A Generalist Predator Community, Stella F Uiterwaal, Amber Squires, Bennett Grappone, Brian Dillard, Ariadne Castaneda, Sora L. Kim, John Delong

School of Biological Sciences: Faculty Publications

1. Niche differentiation and intraguild predation (IGP) can allow ecologically similar species to coexist, although it is unclear which coexistence mechanism predominates in consumer communities. Until now, a limited ability to quantify diets from metabarcoding data has precluded the use of sequencing data to determine the relative importance of these mechanisms.

2. Here, we pair a recent metabarcoding quantification approach with stable isotope analysis to examine diet composition in a wolf spider community.

3. We compare the prevalence of resource partitioning and IGP in these spiders and test whether factors that influence foraging performance, including individual identity, morphology, prey community …

Functionally Redundant Multimodal Predator Cues Elicit Changes In Prey Foraging Behavior, Fiona G. Shogren, Eileen Hebets, John Delong

School of Biological Sciences: Faculty Publications

Many prey species can assess the risk of predation from information acquired through different sensory systems. For many animals, this information is detected with sensory organs specialized for visual (sight) or chemical (smell or taste) stimuli. It is unclear; however, whether information acquired through multiple sensory systems is functionally redundant or interchangeable, especially if the message is the same. Here, we assess prey response to unimodal visual and chemical cues as well as multimodal (visual + chemical) cues. We specifically test if a foraging individual shows a stronger behavioral response to risk when they can perceive that risk through multimodal …

Pathways Of Density Dependence And Natural Selection In Modern Humans, John Delong

School of Biological Sciences: Faculty Publications

Living things depend on a flow of energy and materials to grow, reproduce, and maintain their bodies. Populations are aggregations of individuals, so they too depend on resources. Humans use many fuels derived from the Earth’s photosynthetic energy, which in turn support a population that often occurs at unusually high densities for a mammal. Like most populations, growing human populations may experience negative feedbacks from population size unless the socio-economic system in which the population lives grows fast enough to maintain resource flows to individuals and to limit the downsides of high density. I map out a simple view of …

The Consumption Of Viruses Returns Energy To Food Chains, John Delong, James L. Van Etten, Zeina Al-Ameeli, Irina Agarkova, David Dunigan

School of Biological Sciences: Faculty Publications

Viruses impact host cells and have indirect effects on ecosystem processes. Plankton such as ciliates can reduce the abundance of virions in water, but whether virus consumption translates into demographic consequences for the grazers is unknown. Here, we show that small protists not only can consume viruses they also can grow and divide given only viruses to eat. Moreover, the ciliate Halteria sp. foraging on chloroviruses displays dynamics and interaction parameters that are similar to other microbial trophic interactions. These results suggest that the effect of viruses on ecosystems extends beyond (and in contrast to) the viral shunt by redirecting …