Life Sciences Commons^™

Time Domains Of Hypoxia Responses And -Omics Insights, James J. Yu, Amy L. Non, Erica C. Heinrich, Wanjun Gu, Joe Alcock, Esteban A. Moya, Elijah S. Lawrence, Michael S. Tift, Katie A. O'Brien, Jay F. Storz, Anthony V. Signore, Jane I. Khudyakov, William K. Milsom, Sean M. Wilson, Cynthia M. Beall, Francisco C. Villafuerte, Tsering Stobdan, Colleen G. Julian, Lorna G. Moore, Mark M. Fuster, Jennifer A. Stokes, Richard Milner, John B. West, Jiao Zhang, John Y. Shyy, Ainash Childebayeva, José Pablo Vázquez-Medina, Luu V. Pham, Omar A. Mesarwi, James E. Hall, Zachary A. Cheviron, Jeremy Sieker, Arlin B. Blood, Jason X. Yuan, Tatum S. Simonson, Et Al.

School of Biological Sciences: Faculty Publications

The ability to respond rapidly to changes in oxygen tension is critical for many forms of life. Challenges to oxygen homeostasis, specifically in the contexts of evolutionary biology and biomedicine, provide important insights into mechanisms of hypoxia adaptation and tolerance. Here we synthesize findings across varying time domains of hypoxia in terms of oxygen delivery, ranging from early animal to modern human evolution and examine the potential impacts of environmental and clinical challenges through emerging multi-omics approaches. We discuss how diverse animal species have adapted to hypoxic environments, how humans vary in their responses to hypoxia (i.e., in the context …

Importance Of Local Weather And Environmental Gradients On Demography Of A Broadly Distributed Temperate Frog, Hallie Lingo, James C. Munger

Biology Faculty Publications and Presentations

Amphibian populations are sensitive to environmental temperatures and moisture, which vary with local weather conditions and may reach new norms and extremes as contemporary climate change progresses. Using long-term (11–16 years) mark-recapture data from 10 populations of the Columbia spotted frog (Rana luteiventris) from across its U.S. range, we addressed hypotheses about how demographic relationships to weather depend upon a population’s position along climate gradients. We estimated the effect of seasonal weather on annual survival probability and recruitment rates both within populations and across the species’ range from subalpine forests to semi-arid deserts. We calculated population-specific weather variables …

A Draft Genome Provides Hypotheses On Drought Tolerance In A Keystone Plant Species In Western North America Threatened By Climate Change, Anthony E. Melton, James Beck, Stephanie J. Galla, Marcelo Serpe, Stephen Novak, Sven Buerki

Biology Faculty Publications and Presentations

Climate change presents distinct ecological and physiological challenges to plants as extreme climate events become more common. Understanding how species have adapted to drought, especially ecologically important nonmodel organisms, will be crucial to elucidate potential biological pathways for drought adaptation and inform conservation strategies. To aid in genome-to-phenome research, a draft genome was assembled for a diploid individual of Artemisia tridentata subsp. tridentata, a threatened keystone shrub in western North America. While this taxon has few genetic resources available and genetic/genomics work has proven difficult due to genetic heterozygosity in the past, a draft genome was successfully assembled. Aquaporin …

Diminishing Opportunities For Sustainability Of Coastal Cities In The Anthropocene: A Review, John W. Day, Joel D. Gunn, Joseph Robert Burger

Biology Faculty Publications

The world is urbanizing most rapidly in tropical to sub-temperate areas and in coastal zones. Climate change along with other global change forcings will diminish the opportunities for sustainability of cities, especially in coastal areas in low-income countries. Climate forcings include global temperature and heatwave increases that are expanding the equatorial tropical belt, sea-level rise, an increase in the frequency of the most intense tropical cyclones, both increases and decreases in freshwater inputs to coastal zones, and increasingly severe extreme precipitation events, droughts, freshwater shortages, heat waves, and wildfires. Current climate impacts are already strongly influencing natural and human systems. …

Epigenetics As Driver Of Adaptation And Diversification In Microbial Eukaryotes, Agnes K.M. Weiner, Laura A. Katz

Biological Sciences: Faculty Publications

No abstract provided.

Evolutionary Dynamics And Structural Consequences Of De Novo Beneficial Mutations And Mutant Lineages Arising In A Constant Environment, Margie Kinnersley, Katja Schwartz, Dong Dong Yang, Gavin Sherlock, Frank Rosenzweig

Biological Sciences Faculty Publications

Background: Microbial evolution experiments can be used to study the tempo and dynamics of evolutionary change in asexual populations, founded from single clones and growing into large populations with multiple clonal lineages. High-throughput sequencing can be used to catalog de novo mutations as potential targets of selection, determine in which lineages they arise, and track the fates of those lineages. Here, we describe a long-term experimental evolution study to identify targets of selection and to determine when, where, and how often those targets are hit. Results: We experimentally evolved replicate Escherichia coli populations that originated from a mutator/nonsense suppressor ancestor …

Within- And Trans-Generational Environmental Adaptation To Climate Change: Perspectives And New Challenges, Naim M. Bautista, Amélie Crespel

School of Biological Sciences: Faculty Publications

The current and projected impacts of climate change are shaped by unprecedented rates of change in environmental conditions. These changes likely mismatch the existing coping capacities of organisms within-generations and impose challenges for population resilience across generations. To better understand the impacts of projected scenarios of climate change on organismal fitness and population maintenance, it is crucial to consider and integrate the proximate sources of variability of plastic and adaptive responses to environmental change in future empirical approaches. Here we explore the implications of considering: (a) the variability in different time-scale events of climate change; (b) the variability in plastic …

Predators As Agents Of Selection And Diversification, Jerald B. Johnson, Mark C. Belk

Faculty Publications

Predation is ubiquitous in nature and can be an important component of both ecological and evolutionary interactions. One of the most striking features of predators is how often they cause evolutionary diversification in natural systems. Here, we review several ways that this can occur, exploring empirical evidence and suggesting promising areas for future work. We also introduce several papers recently accepted in Diversity that demonstrate just how important and varied predation can be as an agent of natural selection. We conclude that there is still much to be done in this field, especially in areas where multiple predator species prey …

Experimental Psychology Meets Behavioral Ecology: What Laboratory Studies Of Learning Polymorphisms Mean For Learning Under Natural Conditions, And Vice Versa, Brian H. Smith, Chelsea N. Cook

Biological Sciences Faculty Research and Publications

Behavior genetics, and specifically the study of learning and memory, has benefitted immensely from the development of powerful forward- and reverse-genetic methods for investigating the relationships between genes and behavior. Application of these methods in controlled laboratory settings has led to insights into gene–behavior relationships. In this perspective article, we argue that the field is now poised to make significant inroads into understanding the adaptive value of heritable variation in behavior in natural populations. Studies of natural variation with several species, in particular, are now in a position to complement laboratory studies of mechanisms, and sometimes this work can lead …

Positive Genetic Associations Among Fitness Traits Support Evolvability Of A Reef-Building Coral Under Multiple Stressors, Rachel M. Wright, Hanaka Mera, Carly D. Kenkel, Maria Nayfa, Line K. Bay, Mikhail V. Matz

Biological Sciences: Faculty Publications

Climate change threatens organisms in a variety of interactive ways that requires simultaneous adaptation of multiple traits. Predicting evolutionary responses requires an understanding of the potential for interactions among stressors and the genetic variance and covariance among fitness-related traits that may reinforce or constrain an adaptive response. Here we investigate the capacity of Acropora millepora, a reef-building coral, to adapt to multiple environmental stressors: rising sea surface temperature, ocean acidification, and increased prevalence of infectious diseases. We measured growth rates (weight gain), coral color (a proxy for Symbiodiniaceae density), and survival, in addition to nine physiological indicators of coral and …

Getting Back To Nature: Feralization In Animals And Plants, Eben Gering, Darren Incorvaia, R. Henriksen, Jeffrey Conner, Thomas Getty, Dominic Wright

Biology Faculty Articles

Formerly domesticated organisms and artificially selected genes often escape controlled cultivation, but their subsequent evolution is not well studied. In this review, we examine plant and animal feralization through an evolutionary lens, including how natural selection, artificial selection, and gene flow shape feral genomes, traits, and fitness. Available evidence shows that feralization is not a mere reversal of domestication. Instead, it is shaped by the varied and complex histories of feral populations, and by novel selection pressures. To stimulate further insight we outline several future directions. These include testing how ‘domestication genes’ act in wild settings, studying the brains and …

Maladaptation In Feral And Domesticated Animals, Eben Gering, Darren Incorvaia, R. Henriksen, Dominic Wright

Biology Faculty Articles

Selection regimes and population structures can be powerfully changed by domestication and feralization, and these changes can modulate animal fitness in both captive and natural environments. In this review, we synthesize recent studies of these two processes and consider their impacts on organismal and population fitness. Domestication and feralization offer multiple windows into the forms and mechanisms of maladaptation. Firstly, domestic and feral organisms that exhibit suboptimal traits or fitness allow us to identify their underlying causes within tractable research systems. This has facilitated significant progress in our general understandings of genotype–phenotype relationships, fitness trade‐offs, and the roles of population …

Life Ascending: Mechanism And Process In Physiological Adaptation To High-Altitude Hypoxia, Jay F. Storz, Graham R. Scott

School of Biological Sciences: Faculty Publications

To cope with the reduced availability of O2 at high altitude, air-breathing vertebrates have evolved myriad adjustments in the cardiorespiratory system to match tissue O2 delivery with metabolic O2 demand. We explain how changes at interacting steps of the O2 transport pathway contribute to plastic and evolved changes in whole-animal aerobic performance under hypoxia. In vertebrates native to high altitude, enhancements of aerobic performance under hypoxia are attributable to a combination of environ- mentally induced and evolved changes in multiple steps of the pathway. Additionally, evidence suggests that many high-altitude natives have evolved mechanisms for attenuating maladaptive acclimatization responses to …

Effect Of Temperature Change On Synaptic Transmission At Crayfish Neuromuscular Junctions, Yuechen Zhu, Leo De Castro, Robin L. Cooper

Biology Faculty Publications

Ectothermic animals in areas characterised by seasonal changes are susceptible to extreme fluctuations in temperature. To survive through varied temperatures, ectotherms have developed unique strategies. This study focuses on synaptic transmission function at cold temperatures, as it is a vital component of ectothermic animals' survival. For determining how synaptic transmission is influenced by an acute change in temperature (20°C to 10°C within a minute) and chronic cold (10°C), the crayfish (Procambarus clarkii) neuromuscular junction (NMJ) was used as a model. To simulate chronic cold conditions, crayfish were acclimated to 15°C for 1 week and then to 10°C for …

Environmental Selection During The Last Ice Age On The Mother-To-Infant Transmission Of Vitamin D And Fatty Acids Through Breast Milk, Leslea J. Hlusko, Joshua P. Carlson, George Chaplin, Scott A. Elias, John F. Hoffecker, Michaela Huffman, Nina G. Jablonski, Tesla A. Monson, Dennis H. O'Rourke, Marin A. Pilloud, G. Richard Scott

Anthropology Faculty and Staff Publications

Because of the ubiquitous adaptability of our material culture, some human populations have occupied extreme environments that intensified selection on existing genomic variation. By 32,000 years ago, people were living in Arctic Beringia, and during the Last Glacial Maximum (LGM; 28,000–18,000 y ago), they likely persisted in the Beringian refugium. Such high latitudes provide only very low levels of UV radiation, and can thereby lead to dangerously low levels of biosynthesized vitamin D. The physiological effects of vitamin D deficiency range from reduced dietary absorption of calcium to a compromised immune system and modified adipose tissue function. The ectodysplasin A …

The Evolutionary History Of Nebraska Deer Mice: Local Adaptation In The Face Of Strong Gene Flow, Susanne P Pfeifer, Stefan Laurent, Vitor C. Sousa, Catherine R. Linnen, Matthieu Foll, Laurent Excoffier, Hopi E. Hoekstra, Jeffrey D. Jensen

Biology Faculty Publications

The interplay of gene flow, genetic drift, and local selective pressure is a dynamic process that has been well studied from a theoretical perspective over the last century. Wright and Haldane laid the foundation for expectations under an island-continent model, demonstrating that an island-specific beneficial allele may be maintained locally if the selection coefficient is larger than the rate of migration of the ancestral allele from the continent. Subsequent extensions of this model have provided considerably more insight. Yet, connecting theoretical results with empirical data has proven challenging, owing to a lack of information on the relationship between genotype, phenotype, …

Female Mate Choice Of Male Signals Is Unlikely To Promote Ecological Adaptation In Enchenopa Treehoppers (Hemiptera: Membracidae), Kasey Fowler-Finn, Joseph T. Kilmer, Daniel C. Cruz, Rafael Rodriguez

Biological Sciences Faculty Articles

A key question in speciation research is how ecological and sexual divergence arise and interact. We tested the hypothesis that mate choice causes local adaptation and ecological divergence using the rationale that the performance~signal trait relationship should parallel the attractiveness~signal trait relationship. We used female fecundity as a measure of ecological performance. We used a species in the Enchenopa binotata treehopper complex, wherein speciation involves adaptation to novel environments and divergence in sexual communication. We used a full-sibling, split-family rearing design to estimate genetic correlations (r_G) between fecundity and signal traits, and compared those relationships against population-level …

Family Living Sets The Stage For Cooperative Breeding And Ecological Resilience In Birds, Michael Griesser, Szymon M. Drobniak, Shinichi Nakagawa, Carlos A. Botero

Biology Faculty Publications & Presentations

Cooperative breeding is an extreme form of cooperation that evolved in a range of lineages, including arthropods, fish, birds, and mammals. Although cooperative breeding in birds is widespread and well-studied, the conditions that favored its evolution are still unclear. Based on phylogenetic comparative analyses on 3,005 bird species, we demonstrate here that family living acted as an essential stepping stone in the evolution of cooperative breeding in the vast majority of species. First, families formed by prolonging parent–offspring associations beyond nutritional independency, and second, retained offspring began helping at the nest. These findings suggest that assessment of the conditions that …

Earlier Nesting By Generalist Predatory Bird Is Associated With Human Responses To Climate Change, Shawn H. Smith, Karen Steenhof, Christopher J.W. Mcclure, Julie A. Heath

Biology Faculty Publications and Presentations

1. Warming temperatures cause temporal changes in growing seasons and prey abundance that drive earlier breeding by birds, especially dietary specialists within homogeneous habitat. Less is known about how generalists respond to climate-associated shifts in growing seasons or prey phenology, which may occur at different rates across land cover types.
2. We studied whether breeding phenology of a generalist predator, the American kestrel (Falco sparverius), was associated with shifts in growing seasons and, presumably, prey abundance, in a mosaic of non-irrigated shrub/grasslands and irrigated crops/pastures. We examined the relationship between remotely-sensed normalized difference vegetation index (NDVI) and abundance of small …

Can We Predict Ectotherm Responses To Climate Change Using Thermal Performance Curves And Body Temperatures?, Brent J Sinclair, Katie E Marshall, Mary A Sewell, Danielle L Levesque, Christopher S Willett, Stine Slotsbo, Yunwei Dong, Christopher D G Harley, David J Marshall, Brian S Helmuth, Raymond B Huey

Biology Publications

Thermal performance curves (TPCs), which quantify how an ectotherm's body temperature (Tb ) affects its performance or fitness, are often used in an attempt to predict organismal responses to climate change. Here, we examine the key - but often biologically unreasonable - assumptions underlying this approach; for example, that physiology and thermal regimes are invariant over ontogeny, space and time, and also that TPCs are independent of previously experienced Tb. We show how a critical consideration of these assumptions can lead to biologically useful hypotheses and experimental designs. For example, rather than assuming that TPCs are fixed during ontogeny, one …

Drought Responsive Gene Expression Regulatory Divergence Between Upland And Lowland Ecotypes Of A Perennial C4 Grass, John T. Lovell, Scott Schwartz, David B. Lowry, Eugene V. Shakirov, Jason E. Bonnette, Xiaoyu Weng, Mei Wang, Jenifer Johnson, Avinash Sreedasyam, Christopher Plott, Jerry Jenkins, Jeremy Schmutz, Thomas E. Juenger

Biological Sciences Faculty Research

Climatic adaptation is an example of a genotype-by-environment interaction (G×E) of fitness. Selection upon gene expression regulatory variation can contribute to adaptive phenotypic diversity; however, surprisingly few studies have examined how genome-wide patterns of gene expression G×E are manifested in response to environmental stress and other selective agents that cause climatic adaptation. Here, we characterize drought-responsive expression divergence between upland (drought-adapted) and lowland (mesic) ecotypes of the perennial C₄ grass, Panicum hallii, in natural field conditions. Overall, we find that cis-regulatory elements contributed to gene expression divergence across 47% of genes, 7.2% of which exhibit drought-responsive G×E. …

Beyond The Adaptationist Legacy: Updating Our Teaching To Include A Diversity Of Evolutionary Mechanisms, Rebecca M. Price, Kathryn E. Perez

Biology Faculty Publications and Presentations

A paradigm shift away from viewing evolution primarily in terms of adaptation - the "adaptationist programme" of Gould and Lewontin - began in evolutionary research more than 35 years ago, but that shift has yet to occur within evolutionary education research or within teaching standards. We review three instruments that can help education researchers and educators undertake this paradigm shift. The instruments assess how biology undergraduates understand three evolutionary processes other than natural selection: genetic drift, dominance relationships among allelic pairs, and evolutionary developmental biology (evo-devo). Testing with these instruments reveals that students often explain a diversity of evolutionary mechanisms …

Linking Energetics And Overwintering In Temperate Insects., Brent J Sinclair

Biology Publications

Overwintering insects cannot feed, and energy they take into winter must therefore fuel energy demands during autumn, overwintering, warm periods prior to resumption of development in spring, and subsequent activity. Insects primarily consume lipids during winter, but may also use carbohydrate and proteins as fuel. Because they are ectotherms, the metabolic rate of insects is temperature-dependent, and the curvilinear nature of the metabolic rate-temperature relationship means that warm temperatures are disproportionately important to overwinter energy use. This energy use may be reduced physiologically, by reducing the slope or elevation of the metabolic rate-temperature relationship, or because of threshold changes, such …

Fighting Microbial Drug Resistance: A Primer On The Role Of Evolutionary Biology In Public Health, Gabriel Perron, R. Inglis, Pleuni Pennings, Sarah Cobey

Biology Department Faculty Works

Although microbes have been evolving resistance to antimicrobials for millennia, the spread of resistance in pathogen populations calls for the development of new drugs and treatment strategies. We propose that successful, long-term resistance management requires a better understanding of how resistance evolves in the first place. This is an opportunity for evolutionary biologists to engage in public health, a collaboration that has substantial precedent. Resistance evolution has been an important tool for developing and testing evolutionary theory, especially theory related to the genetic basis of new traits and constraints on adaptation. The present era is no exception. The articles in …

Intraspecific Polymorphism, Interspecific Divergence, And The Origins Of Function-Altering Mutations In Deer Mouse Hemoglobin, Chandrasekhar Natarajan, Federico G. Hoffmann, Hayley C. Lanier, Cole J. Wolf, Zachary A. Cheviron, Matthew L. Spangler, Roy E. Weber, Angela Fago, Jay F. Storz

School of Biological Sciences: Faculty Publications

Major challenges for illuminating the genetic basis of phenotypic evolution are to identify causative mutations, to quantify their functional effects, to trace their origins as new or preexisting variants, and to assess the manner in which segregating variation is transduced into species differences. Here, we report an experimental analysis of genetic variation in hemoglobin (Hb) function within and among species of Peromyscus mice that are native to different elevations. A multilocus survey of sequence variation in the duplicated HBA and HBB genes in Peromyscus maniculatus revealed that function-altering amino acid variants are widely shared among geographically disparate populations

from different …

Epistasis Constrains Mutational Pathways Of Hemoglobin Adaptation In High-Altitude Pikas, Danielle M. Tufts, Chandrasekhar Natarajan, Inge G. Revsbech, Joana Projecto- Garcia, Federico G. Hoffmann, Roy E. Weber, Angela Fago, Hideaki Moriyama, Jay F. Storz

School of Biological Sciences: Faculty Publications

A fundamental question in evolutionary genetics concerns the roles of mutational pleiotropy and epistasis in shaping trajectories of protein evolution. This question can be addressed most directly by using site-directed mutagenesis to explore the mutational landscape of protein function in experimentally defined regions of sequence space. Here, we evaluate how pleiotropic trade-offs and epistatic interactions influence the accessibility of alternative mutational pathways during the adaptive evolution of hemoglobin (Hb) function in high-altitude pikas (Mammalia: Lagomorpha). By combining ancestral protein resurrection with a combinatorial protein-engineering approach, we examined the functional effects of sequential mutational steps in all possible pathways that produced …

Characterizing The Evolutionary Path(S) To Early Homo, Lauren Schroeder, Charles C. Roseman, James M. Cheverud, Rebecca R. Ackermann

Biology: Faculty Publications and Other Works

Numerous studies suggest that the transition from Australopithecus to Homo was characterized by evolutionary innovation, resulting in the emergence and coexistence of a diversity of forms. However, the evolutionary processes necessary to drive such a transition have not been examined. Here, we apply statistical tests developed from quantitative evolutionary theory to assess whether morphological differences among late australopith and early Homo species in Africa have been shaped by natural selection. Where selection is demonstrated, we identify aspects of morphology that were most likely under selective pressure, and determine the nature (type, rate) of that selection. Results demonstrate that selection must …

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 …

Herbivory In The Northern Curly-Tailed Lizard (Leiocephalus Carinatus), Bonnie K. Kircher, Christopher D. Robinson, Michele A. Johnson

Biology Faculty Research

No abstract provided.

Fruiting Bodies Of The Social Amoeba Dictyostelium Discoideum Increase Spore Transport By Drosophila, Jeff Smith, David C. Queller, Joan E. Strassmann

Biology Faculty Publications & Presentations

Background: Many microbial phenotypes are the product of cooperative interactions among cells, but their putative fitness benefits are often not well understood. In the cellular slime mold Dictyostelium discoideum , unicellular amoebae aggregate when starved and form multicellular fruiting bodies in which stress-resistant spores are held aloft by dead stalk cells. Fruiting bodies are thought to be adaptations for dispersing spores to new feeding sites, but this has not been directly tested. Here we experimentally test whether fruiting bodies increase the rate at which spores are acquired by passing invertebrates.
Results: Drosophila melanogaster accumulate spores on their surfaces more quickly …