21 Works

Unique genetic signatures of local adaptation over space and time for diapause, an ecologically relevant complex trait, in Drosophila melanogaster

Priscilla A Erickson, Cory A Weller, Daniel Y Song, Paul Schmidt, Alan O Bergland & Alyssa Bangerter
Organisms living in seasonally variable environments utilize cues such as light and temperature to induce plastic responses, enabling them to exploit favorable seasons and avoid unfavorable ones. Local adapation can result in variation in seasonal responses, but the genetic basis and evolutionary history of this variation remains elusive. Many insects, including Drosophila melanogaster, are able to undergo an arrest of reproductive development (diapause) in response to unfavorable conditions. In D. melanogaster, the ability to diapause...

The effects of age on the demography of a perennial plant depend on interactions with size and environment

Heide Maria Baden, Johan P. Dahlgren, Deborah Ann Roach, Fritz Hans Schweingruber, Kasper Reitzel & Kim Lundgreen
Age-dependence of the demographic rates survival, fecundity and individual growth is a fundamental aspect of population biological theory. Knowledge about plant ageing can also be important for conservation and agriculture as it will improve the accuracy of population viability assessments and long-term performance assessments in perennial crops. Recent studies show age effects on demographic rates for several plant species, yet much remains to be learned about the patterns and mechanisms of plant ageing, particularly about...

Sex linkage of the skeletal muscle sodium channel gene (SCN4A) explains apparent deviations from Hardy–Weinberg equilibrium of tetrodotoxin-resistance alleles in garter snakes (Thamnophis sirtalis)

Kerry Gendreau, Michael Hague, Chris Feldman, , & Joel McGlothlin
The arms race between tetrodotoxin-bearing Pacific newts (Taricha) and their garter snake predators (Thamnophis) in western North America has become a classic example of coevolution, shedding light on predator-prey dynamics, the molecular basis of adaptation, and patterns of convergent evolution. Newts are defended by tetrodotoxin (TTX), a neurotoxin that binds to voltage-gated sodium channels (Nav proteins), arresting electrical activity in nerves and muscles and paralyzing would-be predators. However, populations of the common garter snake (T....

Data from: A threat to loyalty: Fear of missing out (FOMO) leads to reluctance to repeat current experiences

Ceren Hayran, Lalin Anik & Zeynep Gürhan-Canli
We investigate a popular but underresearched concept, the fear of missing out (FOMO), on desirable experiences of which an individual is aware, but in which they do not partake. Through laboratory and field studies, we establish FOMO’s pervasiveness as a psychological phenomenon, present real-life contexts wherein FOMO may be experienced, and explore its behavioral consequences. Specifically, we show that FOMO poses a threat to loyalty by decreasing one’s intentions to repeat a current experience and...

Ambulatory physicians’ electronic health record self-efficacy

Martha Hellems
Objective: To assess ambulatory providers’ confidence in learning about and using the electronic health record (EHR). Materials and Methods: Providers were administered an EHR skills self-assessment survey. Results: 71 providers participated. Only 35% of respondents felt that they had strong EHR skills, 92% felt confident that they could learn new skills, and 90% felt they could improve with practice. 45% of faculty physicians felt confident that they could use the EHR in a time-efficient manner...

Data from: Validation of serum neurofilaments as prognostic & potential pharmacodynamic biomarkers for ALS

Michael Benatar, Lanyu Zhang, Lily Wang, Volkan Granit, Jeffrey Statland, Richard Barohn, Andrea Swenson, John Ravitz, Carlayne Jackson, Ted Burns, Jaya Trivedi, Erik Pioro, James Caress, Jonathan Katz, Jacob McCauley, Rosa Rademakers, Andrea Malaspina, Lyle Ostrow & Joanne Wuu
Objective. Identify preferred neurofilament assays, and clinically validate serum NfL and pNfH as prognostic and potential pharmacodynamic biomarkers relevant to ALS therapy development. Methods. Prospective, multi-center, longitudinal observational study of patients with ALS (n=229), primary lateral sclerosis (PLS, n=20) and progressive muscular atrophy (PMA, n=11). Biological specimens were collected, processed and stored according to strict standard operating procedures (SOPs) 1. Neurofilament assays were performed in a blinded manner by independent contract research organizations (CROs). Results....

Host heterogeneity mitigates virulence evolution

P. Signe White, Angela Choi, Rishika Pandey, Arthur Menezes, McKenna Penley, Amanda Gibson, Jacobus De Roode, Levi Morran & Amanda K. Gibson
Parasites often infect genetically diverse host populations, and the evolutionary trajectories of parasite populations may be shaped by levels of host heterogeneity. Mixed genotype host populations, compared to homogeneous host populations, can reduce parasite prevalence and potentially reduce rates of parasite adaptation due to tradeoffs associated with adapting to specific host genotypes. Here, we used experimental evolution to select for increased virulence in populations of the bacterial parasite Serratia marcescens exposed to either heterogenous or...

Data from: The evolution of parasite host range in heterogeneous host populations

Amanda Gibson, Helena Baffoe-Bonnie, McKenna Penley, Julie Lin, Raythe Owens, Arooj Khalid & Levi Morran
Theory on the evolution of niche width argues that resource heterogeneity selects for niche breadth. For parasites, this theory predicts that parasite populations will evolve, or maintain, broader host ranges when selected in genetically diverse host populations relative to homogeneous host populations. To test this prediction, we selected the bacterial parasite Serratia marcescens to kill Caenorhabditis elegans in populations that were genetically heterogeneous (50% mix of two experimental genotypes) or homogeneous (100% of either genotype)....

Pollen color morphs take different paths to fitness

Matthew Koski, Andrea Berardi & Laura Galloway
Color phenotypes are often involved in communication and are thus under selection by species interactions. However, selection may also act on color through correlated traits or alternative functions of biochemical pigments. Such forms of selection are instrumental in maintaining petal color diversity in plants. Pollen color also varies markedly, but the maintenance of this variation is little understood. In Campanula americana, pollen ranges from white to dark purple, with darker morphs garnering more pollinator visits...

Data from: Nonlinearities between inhibition and T-type calcium channel activity bidirectionally regulate thalamic oscillations

Adam Lu, Christine Lee, Max Kleiman-Weiner, Brian Truong, Megan Wang, John Huguenard & Mark Beenhakker
Absence seizures result from 3-5 Hz generalized thalamocortical oscillations that depend on highly regulated inhibitory neurotransmission in the thalamus. Efficient reuptake of the inhibitory neurotransmitter GABA is essential, and reuptake failure worsens seizures. Here, we show that blocking GABA transporters (GATs) in acute brain slices containing key parts of the thalamocortical seizure network modulates epileptiform activity. As expected, we found that blocking either GAT1 or GAT3 prolonged oscillations. However, blocking both GATs unexpectedly suppressed oscillations....

Strength in numbers? Cytotype frequency mediates effect of reproductive barriers in mixed-ploidy arrays.

Brittany Sutherland, Tomas Miranda-Katz & Laura Galloway
When differentiated lineages come into contact, their fates depend on demographic and reproductive factors. These factors have been well-studied in taxa of the same ploidy, but less is known about sympatric lineages that differ in ploidy, particularly with respect to demographic factors. We assessed prezygotic, postzygotic, and total reproductive isolation in naturally-pollinated arrays of diploid-tetraploid and tetraploid-hexaploid population mixes of Campanula rotundifolia by measuring pollinator transitions, seed yield, germination rate, and proportion of hybrid offspring....

Data from: The geographic mosaic of arms race coevolution is closely matched to prey population structure

Michael Hague, Amber Stokes, Chris Feldman, Edmund Brodie &
Reciprocal adaptation is the hallmark of arms race coevolution. Local coadaptation between natural enemies should generate a geographic mosaic pattern where both species have roughly matched abilities across their shared range. However, mosaic variation in ecologically relevant traits can also arise from processes unrelated to reciprocal selection, such as population structure or local environmental conditions. We tested whether these alternative processes can account for trait variation in the geographic mosaic of arms race coevolution between...

Data from: Exploring density and frequency dependent interactions experimentally: an R program for generating hexagonal fan designs.

Carly Rozins, Janis Antonovics, Michael Hood & Jae Hoon Cho
Species interactions and diversity are strongly impacted by local processes, with both the density of a focal species and its frequency in the community having an impact on its growth, survival, and fecundity. Yet, studies that attempt to control for variation in both frequency and density have traditionally required a large number of replicates. Hexagonal fan designs can include a range of both densities and frequencies in a single plot, providing large economies in space...

Westward range expansion from middle latitudes explains the Mississippi River discontinuity in a forest herb of eastern North America

Carly Prior, Nate Layman, Matthew Koski, Laura Galloway & Jeremiah Busch
It is often expected that temperate plants have expanded their geographic ranges northward from primarily southern refugia. Evidence for this hypothesis is mixed in eastern North American species, and there is increasing support for colonization from middle latitudes. We studied genome-wide patterns of variation in RADseq loci to test hypotheses concerning range expansion in a North American forest herb (Campanula americana). First, spatial patterns of genetic differentiation were determined. Then phylogenetic relationships and divergence times...

Male competition reverses female preference for male chemical cues

Lisa Mitchem
Females must choose among potential mates with different phenotypes in a variety of social contexts. Many male traits are inherent and unchanging, but others are labile to social context. Competition, for example, can cause physiological changes that reflect recent wins and losses which fluctuate throughout time. We may expect females to respond differently to males depending on the outcome of their most recent fight. In Bolitotherus cornutus (forked fungus beetles), males compete for access to...

An experimental test of parasite adaptation to common vs. rare host genotypes

Amanda Gibson, P. Signe White, McKenna Penley, Jacobus De Roode & Levi Morran
A core hypothesis in coevolutionary theory proposes that parasites adapt to specifically infect common host genotypes. Under this hypothesis, parasites function as agents of negative frequency-dependent selection, favoring rare host genotypes. This parasite-mediated advantage of rarity is key to the idea that parasites maintain genetic variation and select for outcrossing in host populations. Here, we report the results of an experimental test of parasite adaptation to common vs. rare host genotypes. We selected the bacterial...

Dead litter of resident species first facilitates and then inhibits sequential life stages of range-expanding species

Rachel Smith, Julie Blaze & James Byers
1. Resident species can facilitate invading species (biotic assistance) or inhibit their expansion (biotic resistance). Species interactions are often context-dependent and the relative importance of biotic assistance versus resistance could vary with abiotic conditions or the life stage of the invading species, as invader stress tolerances and resource requirements change with ontogeny. In northeast Florida salt marshes, the abundant dead litter (wrack) of the native marsh cordgrass, Spartina alterniflora, could influence the expansion success of...

Does genetic diversity protect host populations from parasites? A meta-analysis across natural and agricultural systems

Amanda Gibson & Anna Nguyen
If parasites transmit more readily between closely related hosts, then parasite burdens should decrease with increased genetic diversity of host populations. This important hypothesis is often accepted at face value - notorious epidemics of crop monocultures testify to the vulnerability of host populations that have been purged of diversity. Yet the relationship between genetic diversity and parasitism likely varies across contexts, differing between crop and non-crop hosts and between experimental and natural host populations. Here,...

Additional references for: Brain arteriovenous malformations: a review of natural history, pathobiology, and interventions

Jason Sheehan & Ching-Jen Chen
Brain arteriovenous malformations (AVMs) are anomalous direct shunts between cerebral arteries and veins that convalesce into a vascular nidus. The treatment strategies for AVMs are challenging and variable. Intracranial hemorrhage and seizures comprise the most common presentations of AVMs. However, incidental AVMs are being diagnosed with increasing frequency due to widespread use of noninvasive neuroimaging. The balance between the estimated cumulative lifetime hemorrhage risk versus the risk of intervention is often the major determinant for...

Self-organising cicada choruses respond to the local sound and light environment

Lawrence Sheppard, Brandon Mechtley, Jonathan Walter & Daniel Reuman
1. Periodical cicadas exhibit an extraordinary capacity for self-organising spatially synchronous breeding behavior. The regular emergence of periodical cicada broods across the US is a phenomenon of longstanding public and scientific interest, as the cicadas of each brood emerge in huge numbers and briefly dominate their ecosystem. During the emergence, the 17-year periodical cicada species Magicicada cassini is found to form synchronised choruses, and we investigated their chorusing behavior from the standpoint of spatial synchrony....

Data from: Synchronous effects produce cycles in deer populations and deer-vehicle collisions

Thomas Anderson, Lawrence Sheppard, Jon Walter, Robert Rolley & Dan Reuman
Population cycles are fundamentally linked with spatial synchrony, the prevailing paradigm being that populations with cyclic dynamics are easily synchronized. That is, population cycles help give rise to spatial synchrony. Here we demonstrate this process can work in reverse, with synchrony causing population cycles. We show that timescale-specific environmental effects, by synchronizing local population dynamics on certain timescales only, cause major population cycles over large areas in white-tailed deer. An important aspect of the new...

Registration Year

  • 2020

Resource Types

  • Dataset


  • University of Virginia
  • University of Kansas
  • University of Montana
  • Utah State University
  • University of Georgia
  • University of Nevada Reno
  • Clemson University
  • Massachusetts General Hospital
  • University of Pennsylvania
  • Stanford University