Carl T Bergstrom

University of Washington Seattle, Seattle, Washington, United States

Are you Carl T Bergstrom?

Claim your profile

Publications (102)481.35 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Two categories of evolutionary challenges result from escalating human impacts on the planet. The first arises from cancers, pathogens, and pests that evolve too quickly and the second, from the inability of many valued species to adapt quickly enough. Applied evolutionary biology provides a suite of strategies to address these global challenges that threaten human health, food security, and biodiversity. This Review highlights both progress and gaps in genetic, developmental, and environmental manipulations across the life sciences that either target the rate and direction of evolution or reduce the mismatch between organisms and human-altered environments. Increased development and application of these underused tools will be vital in meeting current and future targets for sustainable development.
    Science 10/2014; 346. · 31.03 Impact Factor
  • Source
  • Jevin D. West, Theodore Bergstrom, Carl T. Bergstrom
    [Show abstract] [Hide abstract]
    ABSTRACT: Open access publishing has been proposed as one possible solution to the serials crisis—the rapidly growing subscription prices in scholarly journal publishing. However, open access publishing can present economic pitfalls as well, such as excessive article processing charges. We discuss the decision that an author faces when choosing to submit to an open access journal. We develop an interactive tool to help authors compare among alternative open access venues and thereby get the most for their article processing charges. (JEL I2, C1, A1)
    Economic Inquiry 06/2014; · 0.98 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Abstract In many species, nongenetic phenotypic variation helps mitigate risk associated with an uncertain environment. In some cases, developmental cues can be used to match phenotype to environment-a strategy known as predictive plasticity. When environmental conditions are entirely unpredictable, generating random phenotypic diversity may improve the long-term success of a lineage-a strategy known as diversified bet hedging. When partially reliable information is available, a well-adapted developmental strategy may strike a balance between the two strategies. We use information theory to analyze a model of development in an uncertain environment, where cue reliability is affected by variation both within and between generations. We show that within-generation variation in cues decreases the reliability of cues without affecting their fitness value. This transpires because the optimal balance of predictive plasticity and diversified bet hedging is unchanged. However, within-generation variation in cues does change the developmental mechanisms used to create that balance: developmental sensitivity to such cues not only helps match phenotype to environment but also creates phenotypic diversity that may be useful for hedging bets against environmental change. Understanding the adaptive role of developmental sensitivity thus depends on a proper assessment of both the predictive power and the structure of variation in environmental cues.
    The American Naturalist 09/2013; 182(3):313-27. · 4.55 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Biogeographic patterns of survival help constrain the causal factors responsible for mass extinction. To test whether biogeography influenced end-Cretaceous (K-Pg) extinction patterns, we used a network approach to delimit biogeographic units (BUs) above the species level in a global Maastrichtian database of 329 bivalve genera. Geographic range is thought to buffer taxa from extinction, but the number of BUs a taxon occurred in superseded geographic range as an extinction predictor. Geographically, we found a latitudinal selectivity gradient for geographic range in the K-Pg, such that higher latitude BUs had lower extinction than expected given the geographic ranges of the genera, implying that (i) high latitude BUs were more resistant to extinction, (ii) the intensity of the K-Pg kill mechanism declined with distance from the tropics, or (iii) both. Our results highlight the importance of macroecological structure in constraining causal mechanisms of extinction and estimating extinction risk of taxa.
    Scientific Reports 05/2013; 3:1790. · 5.08 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Gender disparities appear to be decreasing in academia according to a number of metrics, such as grant funding, hiring, acceptance at scholarly journals, and productivity, and it might be tempting to think that gender inequity will soon be a problem of the past. However, a large-scale analysis based on over eight million papers across the natural sciences, social sciences, and humanities reveals a number of understated and persistent ways in which gender inequities remain. For instance, even where raw publication counts seem to be equal between genders, close inspection reveals that, in certain fields, men predominate in the prestigious first and last author positions. Moreover, women are significantly underrepresented as authors of single-authored papers. Academics should be aware of the subtle ways that gender disparities can occur in scholarly authorship.
    PLoS ONE 01/2013; 8(7):e66212. · 3.53 Impact Factor
  • Frazer Meacham, Aaron Perlmutter, Carl T Bergstrom
    [Show abstract] [Hide abstract]
    ABSTRACT: Costly signalling theory is commonly invoked as an explanation for how honest communication can be stable when interests conflict. However, the signal costs predicted by costly signalling models often turn out to be unrealistically high. These models generally assume that signal cost is determinate. Here, we consider the case where signal cost is instead stochastic. We examine both discrete and continuous signalling games and show that, under reasonable assumptions, stochasticity in signal costs can decrease the average cost at equilibrium for all individuals. This effect of stochasticity for decreasing signal costs is a fundamental mechanism that probably acts in a wide variety of circumstances.
    Journal of The Royal Society Interface 01/2013; 10(87):20130469. · 4.91 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The authors describe a classroom experiment designed to present the idea of two-sided matching, the concept of a stable assignment, and the Gale-Shapley deferred-acceptance mechanism. Participants need no prior training in economics or game theory, but the exercise will also interest trained economists and game theorists.
    The Journal of Economic Education 01/2013; 44(1). · 0.25 Impact Factor
  • Source
    Erick Chastain, Rustom Antia, Carl T. Bergstrom
    [Show abstract] [Hide abstract]
    ABSTRACT: One strategy for winning a coevolutionary struggle is to evolve rapidly. Most of the literature on host-pathogen coevolution focuses on this phenomenon, and looks for consequent evidence of coevolutionary arms races. An alternative strategy, less often considered in the literature, is to deter rapid evolutionary change by the opponent. To study how this can be done, we construct an evolutionary game between a controller that must process information, and an adversary that can tamper with this information processing. In this game, a species can foil its antagonist by processing information in a way that is hard for the antagonist to manipulate. We show that the structure of the information processing system induces a fitness landscape on which the adversary population evolves. Complex processing logic can carve long, deep fitness valleys that slow adaptive evolution in the adversary population. We suggest that this type of defensive complexity on the part of the vertebrate adaptive immune system may be an important element of coevolutionary dynamics between pathogens and their vertebrate hosts. Furthermore, we cite evidence that the immune control logic is phylogenetically conserved in mammalian lineages. Thus our model of defensive complexity suggests a new hypothesis for the lower rates of evolution for immune control logic compared to other immune structures.
    11/2012;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Costly signalling theory has become a common explanation for honest communication when interests conflict. In this paper, we provide an alternative explanation for partially honest communication that does not require significant signal costs. We show that this alternative is at least as plausible as traditional costly signalling, and we suggest a number of experiments that might be used to distinguish the two theories.
    Proceedings of the Royal Society B: Biological Sciences 11/2012; · 5.68 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we show how the Eigenfactor(R) score, originally designed for ranking scholarly journals, can be adapted to rank the scholarly output of authors, institutions, and countries based on authorlevel citation data. Using the methods described herein, we provide Eigenfactor rankings for 84,808 disambiguated authors of 240,804 papers in the Social Science Research Network (SSRN) — a pre and post-print archive devoted to the rapid dissemination of scholarly research in the social sciences and humanities. As an additive metric, the Eigenfactor scores are readily computed for collectives such as departments or institutions as well. We show that a collective’s Eigenfactor score can be computed either by summing the Eigenfactor scores of its members, or by working directly with a collective-level cross-citation matrix. To illustrate, we provide Eigenfactor rankings for institutions and countries in the SSRN repository. With a network-wide comparison of Eigenfactor scores and download tallies, we demonstrate that Eigenfactor scores provide information that is both different from and complementary to that provided by download counts. We see author-level ranking as one filter for navigating the scholarly literature, and note that such rankings generate incentives for more open scholarship, as authors are rewarded for making their work available to the community as early as possible and prior to formal publication. NOTE: Because of the incompleteness of the SSRN CiteReader data at this time, please check back at this URL for updated versions of this paper for updated results over the next 2 years. In addition, when citing this paper please include the following: Data as of March 14, 2011.
    Journal of the American Society for Information Science and Technology 08/2012; · 2.01 Impact Factor
  • Source
    Erick Chastain, Rustom Antia, Carl T. Bergstrom
    [Show abstract] [Hide abstract]
    ABSTRACT: One strategy for winning a coevolutionary struggle is to evolve rapidly. Most of the literature on host-pathogen coevolution focuses on this phenomenon, and looks for consequent evidence of coevolutionary arms races. An alternative strategy, less often considered in the literature, is to deter rapid evolutionary change by the opponent. To study how this can be done, we construct an evolutionary game between a controller that must process information, and an adversary that can tamper with this information processing. In this game, a species can foil its antagonist by processing information in a way that is hard for the antagonist to manipulate. We show that the structure of the information processing system induces a fitness landscape on which the adversary population evolves, and that complex processing logic is required to make that landscape rugged. Drawing on the rich literature concerning rates of evolution on rugged landscapes, we show how a species can slow adaptive evolution in the adversary population. We suggest that this type of defensive complexity on the part of the vertebrate adaptive immune system may be an important element of coevolutionary dynamics between pathogens and their vertebrate hosts.
    03/2012;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The interface between evolutionary biology and the biomedical sciences promises to advance understanding of the origins of genetic and infectious diseases in humans, potentially leading to improved medical diagnostics, therapies, and public health practices. The biomedical sciences also provide unparalleled examples for evolutionary biologists to explore. However, gaps persist between evolution and medicine, for historical reasons and because they are often perceived as having disparate goals. Evolutionary biologists have a role in building a bridge between the disciplines by presenting evolutionary biology in the context of human health and medical practice to undergraduates, including premedical and preprofessional students. We suggest that students will find medical examples of evolution engaging. By making the connections between evolution and medicine clear at the undergraduate level, the stage is set for future health providers and biomedical scientists to work productively in this synthetic area. Here, we frame key evolutionary concepts in terms of human health, so that biomedical examples may be more easily incorporated into evolution courses or more specialized courses on evolutionary medicine. Our goal is to aid in building the scientific foundation in evolutionary biology for all students, and to encourage evolutionary biologists to join in the integration of evolution and medicine.
    Evolution 02/2012; 66(6):1991 - 2006. · 4.86 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Structural controllability has been proposed as an analytical framework for making predictions regarding the control of complex networks across myriad disciplines in the physical and life sciences (Liu et al., Nature:473(7346):167-173, 2011). Although the integration of control theory and network analysis is important, we argue that the application of the structural controllability framework to most if not all real-world networks leads to the conclusion that a single control input, applied to the power dominating set, is all that is needed for structural controllability. This result is consistent with the well-known fact that controllability and its dual observability are generic properties of systems. We argue that more important than issues of structural controllability are the questions of whether a system is almost uncontrollable, whether it is almost unobservable, and whether it possesses almost pole-zero cancellations.
    PLoS ONE 01/2012; 7(6):e38398. · 3.53 Impact Factor
  • Source
    Jevin D West, Carl T Bergstrom
    Science 12/2011; 334(6062):1503-4. · 31.20 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We use an information-theoretic approach to describe changes in lending relationships between federal funds market participants around the time of the Lehman Brothers failure. Unlike previous work that conducts maximum-likelihood estimation on undirected networks, our analysis distinguishes between borrowers and lenders and looks for broader lending relationships (multibank lending cycles) that extend beyond the immediate counterparties. We find that significant changes in lending patterns emerge following implementation of the Interest on Reserves policy by the Federal Reserve on October 9, 2008.
    08/2011;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Evolutionary principles are now routinely incorporated into medicine and agriculture. Examples include the design of treatments that slow the evolution of resistance by weeds, pests, and pathogens, and the design of breeding programs that maximize crop yield or quality. Evolutionary principles are also increasingly incorporated into conservation biology, natural resource management, and environmental science. Examples include the protection of small and isolated populations from inbreeding depression, the identification of key traits involved in adaptation to climate change, the design of harvesting regimes that minimize unwanted life-history evolution, and the setting of conservation priorities based on populations, species, or communities that harbor the greatest evolutionary diversity and potential. The adoption of evolutionary principles has proceeded somewhat independently in these different fields, even though the underlying fundamental concepts are the same. We explore these fundamental concepts under four main themes: variation, selection, connectivity, and eco-evolutionary dynamics. Within each theme, we present several key evolutionary principles and illustrate their use in addressing applied problems. We hope that the resulting primer of evolutionary concepts and their practical utility helps to advance a unified multidisciplinary field of applied evolutionary biology.
    Evolutionary Applications 02/2011; 4(2):159 - 183. · 4.15 Impact Factor
  • Source
    Martin Rosvall, Carl T Bergstrom
    [Show abstract] [Hide abstract]
    ABSTRACT: To comprehend the hierarchical organization of large integrated systems, we introduce the hierarchical map equation, which reveals multilevel structures in networks. In this information-theoretic approach, we exploit the duality between compression and pattern detection; by compressing a description of a random walker as a proxy for real flow on a network, we find regularities in the network that induce this system-wide flow. Finding the shortest multilevel description of the random walker therefore gives us the best hierarchical clustering of the network--the optimal number of levels and modular partition at each level--with respect to the dynamics on the network. With a novel search algorithm, we extract and illustrate the rich multilevel organization of several large social and biological networks. For example, from the global air traffic network we uncover countries and continents, and from the pattern of scientific communication we reveal more than 100 scientific fields organized in four major disciplines: life sciences, physical sciences, ecology and earth sciences, and social sciences. In general, we find shallow hierarchical structures in globally interconnected systems, such as neural networks, and rich multilevel organizations in systems with highly separated regions, such as road networks.
    PLoS ONE 01/2011; 6(4):e18209. · 3.53 Impact Factor
  • Source
    Carl T. Bergstrom, Martin Rosvall
    [Show abstract] [Hide abstract]
    ABSTRACT: Biologists rely heavily on the language of information, coding, and transmission that is commonplace in the field of information theory developed by Claude Shannon, but there is open debate about whether such language is anything more than facile metaphor. Philosophers of biology have argued that when biologists talk about information in genes and in evolution, they are not talking about the sort of information that Shannon’s theory addresses. First, philosophers have suggested that Shannon’s theory is only useful for developing a shallow notion of correlation, the so-called “causal sense” of information. Second, they typically argue that in genetics and evolutionary biology, information language is used in a “semantic sense,” whereas semantics are deliberately omitted from Shannon’s theory. Neither critique is well-founded. Here we propose an alternative to the causal and semantic senses of information: a transmission sense of information, in which an object X conveys information if the function of X is to reduce, by virtue of its sequence properties, uncertainty on the part of an agent who observes X. The transmission sense not only captures much of what biologists intend when they talk about information in genes, but also brings Shannon’s theory back to the fore. By taking the viewpoint of a communications engineer and focusing on the decision problem of how information is to be packaged for transport, this approach resolves several problems that have plagued the information concept in biology, and highlights a number of important features of the way that information is encoded, stored, and transmitted as genetic sequence. KeywordsInformation–Evolution–Shannon theory–Natural selection–Entropy–Mutual information
    Biology and Philosophy 01/2011; 26(2):159-176. · 1.10 Impact Factor

Publication Stats

3k Citations
481.35 Total Impact Points

Institutions

  • 2001–2014
    • University of Washington Seattle
      • Department of Biology
      Seattle, Washington, United States
  • 2013
    • The University of Arizona
      • Department of Ecology and Evolutionary Biology
      Tucson, AZ, United States
  • 2000–2013
    • Santa Fe Institute
      Santa Fe, New Mexico, United States
  • 2012
    • Johns Hopkins University
      • Department of Mechanical Engineering
      Baltimore, MD, United States
  • 2011
    • Umeå University
      • Department of Physics
      Umeå, Vaesterbotten, Sweden
    • University of Auckland
      • Liggins Institute
      Auckland, Auckland, New Zealand
  • 2003–2007
    • Harvard University
      • Department of Epidemiology
      Boston, MA, United States
  • 2004
    • Max Planck Institute for Mathematics in the Sciences
      Leipzig, Saxony, Germany
  • 1999–2004
    • Emory University
      • Department of Biology
      Atlanta, GA, United States
  • 1999–2001
    • University of California, Santa Barbara
      • Department of Economics
      Santa Barbara, CA, United States
  • 1998–1999
    • Stanford University
      Palo Alto, California, United States