Life-History Strategies and the Effectiveness of Sexual Selection
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Predators As Agents of Selection and Diversification
diversity Review Predators as Agents of Selection and Diversification Jerald B. Johnson * and Mark C. Belk Evolutionary Ecology Laboratories, Department of Biology, Brigham Young University, Provo, UT 84602, USA; [email protected] * Correspondence: [email protected]; Tel.: +1-801-422-4502 Received: 6 October 2020; Accepted: 29 October 2020; Published: 31 October 2020 Abstract: 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 upon common prey, in certain taxonomic groups where we still know very little, and in an overall effort to actually quantify mortality rates and the strength of natural selection in the wild. Keywords: adaptation; mortality rates; natural selection; predation; prey 1. Introduction In the history of life, a key evolutionary innovation was the ability of some organisms to acquire energy and nutrients by killing and consuming other organisms [1–3]. This phenomenon of predation has evolved independently, multiple times across all known major lineages of life, both extinct and extant [1,2,4]. Quite simply, predators are ubiquitous agents of natural selection. Not surprisingly, prey species have evolved a variety of traits to avoid predation, including traits to avoid detection [4–6], to escape from predators [4,7], to withstand harm from attack [4], to deter predators [4,8], and to confuse or deceive predators [4,8]. -
Effects of Human Disturbance on Terrestrial Apex Predators
diversity Review Effects of Human Disturbance on Terrestrial Apex Predators Andrés Ordiz 1,2,* , Malin Aronsson 1,3, Jens Persson 1 , Ole-Gunnar Støen 4, Jon E. Swenson 2 and Jonas Kindberg 4,5 1 Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, SE-730 91 Riddarhyttan, Sweden; [email protected] (M.A.); [email protected] (J.P.) 2 Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Postbox 5003, NO-1432 Ås, Norway; [email protected] 3 Department of Zoology, Stockholm University, SE-10691 Stockholm, Sweden 4 Norwegian Institute for Nature Research, NO-7485 Trondheim, Norway; [email protected] (O.-G.S.); [email protected] (J.K.) 5 Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden * Correspondence: [email protected] Abstract: The effects of human disturbance spread over virtually all ecosystems and ecological communities on Earth. In this review, we focus on the effects of human disturbance on terrestrial apex predators. We summarize their ecological role in nature and how they respond to different sources of human disturbance. Apex predators control their prey and smaller predators numerically and via behavioral changes to avoid predation risk, which in turn can affect lower trophic levels. Crucially, reducing population numbers and triggering behavioral responses are also the effects that human disturbance causes to apex predators, which may in turn influence their ecological role. Some populations continue to be at the brink of extinction, but others are partially recovering former ranges, via natural recolonization and through reintroductions. -
Energy Flow Through Marine Ecosystems: Confronting Transfer Efficiency
TREE 2756 No. of Pages 11 Trends in Ecology & Evolution Review Energy Flow Through Marine Ecosystems: Confronting Transfer Efficiency Tyler D. Eddy ,1,2,*,@ Joey R. Bernhardt ,3,4,5,@ Julia L. Blanchard,6,7 William W.L. Cheung,3 Mathieu Colléter,8 Hubert du Pontavice ,3,9 Elizabeth A. Fulton,6,10 Didier Gascuel ,9,@ Kelly A. Kearney ,11 Colleen M. Petrik ,12 Tilla Roy,13,14 Ryan R. Rykaczewski ,1,15 Rebecca Selden,16 Charles A. Stock ,17 Colette C.C. Wabnitz ,3,18,19 and Reg A. Watson 6,7 Transfer efficiency is the proportion of energy passed between nodes in food webs. Highlights It is an emergent, unitless property that is difficult to measure, and responds Transfer efficiency is a key parameter de- dynamically to environmental and ecosystem changes. Because the consequences scribing ecosystem structure and func- of changes in transfer efficiency compound through ecosystems, slight variations tion and is used to estimate fisheries production; however, it is also one of can have large effects on food availability for top predators. Here, we review the the most uncertain parameters. processes controlling transfer efficiency, approaches to estimate it, and known variations across ocean biomes. Both process-level analysis and observed macro- Questions remain about how habitats, fi scale variations suggest that ecosystem-scale transfer efficiency is highly variable, food resources, shing pressure, spatio- fi temporal scales, as well as temperature, impacted by shing, and will decline with climate change. It is important that we primary production, and other climate more fully resolve the processes controlling transfer efficiency in models to drivers impact transfer efficiency. -
A Review of Planktivorous Fishes: Their Evolution, Feeding Behaviours, Selectivities, and Impacts
Hydrobiologia 146: 97-167 (1987) 97 0 Dr W. Junk Publishers, Dordrecht - Printed in the Netherlands A review of planktivorous fishes: Their evolution, feeding behaviours, selectivities, and impacts I Xavier Lazzaro ORSTOM (Institut Français de Recherche Scientifique pour le Développement eri Coopération), 213, rue Lu Fayette, 75480 Paris Cedex IO, France Present address: Laboratorio de Limrzologia, Centro de Recursos Hidricob e Ecologia Aplicada, Departamento de Hidraulica e Sarzeamento, Universidade de São Paulo, AV,DI: Carlos Botelho, 1465, São Carlos, Sï? 13560, Brazil t’ Mail address: CI? 337, São Carlos, SI? 13560, Brazil Keywords: planktivorous fish, feeding behaviours, feeding selectivities, electivity indices, fish-plankton interactions, predator-prey models Mots clés: poissons planctophages, comportements alimentaires, sélectivités alimentaires, indices d’électivité, interactions poissons-pltpcton, modèles prédateurs-proies I Résumé La vision classique des limnologistes fut de considérer les interactions cntre les composants des écosystè- mes lacustres comme un flux d’influence unidirectionnel des sels nutritifs vers le phytoplancton, le zoo- plancton, et finalement les poissons, par l’intermédiaire de processus de contrôle successivement physiqucs, chimiques, puis biologiques (StraSkraba, 1967). L‘effet exercé par les poissons plaiictophages sur les commu- nautés zoo- et phytoplanctoniques ne fut reconnu qu’à partir des travaux de HrbáEek et al. (1961), HrbAEek (1962), Brooks & Dodson (1965), et StraSkraba (1965). Ces auteurs montrèrent (1) que dans les étangs et lacs en présence de poissons planctophages prédateurs visuels. les conimuiiautés‘zooplanctoniques étaient com- posées d’espèces de plus petites tailles que celles présentes dans les milieux dépourvus de planctophages et, (2) que les communautés zooplanctoniques résultantes, composées d’espèces de petites tailles, influençaient les communautés phytoplanctoniques. -
The New Talent Landscape: Recruiting Difficulty and Skills Shortages (SHRM, 2016)
THE NEW TALENT LANDSCAPE RECRUITING DIFFICULTY AND SKILLS SHORTAGES THE NEW TALENT LANDSCAPE Recruiting Difficulty and Skills Shortages A RESEARCH REPORT BY THE SOCIETY FOR HUMAN RESOURCE MANAGEMENT Media Contact USA Kate Kennedy SHRM Headquarters Phone: + 1.703.535.6260 Alexandria, VA 22314 The Society for Human Resource Management E-mail: [email protected] Phone +1.800.283.7476 (SHRM) is the world’s largest HR professional society, E-mail [email protected] representing 285,000 members in more than 165 Vanessa Hill countries. For nearly seven decades, the Society Phone: +1.703.535.6072 China has been the leading provider of resources serving E-mail: [email protected] Gateway Plaza the needs of HR professionals and advancing the Chaoyang District Online practice of human resource management. SHRM Beijing, 100027 SHRM Online: shrm.org has more than 575 affiliated chapters within the Phone +86.10.59231033 United States and subsidiary offices in China, India SHRM Research & Surveys: shrm.org/research E-mail [email protected] and United Arab Emirates. Visit us at shrm.org. SHRM Research on Twitter: @SHRM_Research India SHRM Research on LinkedIn: LinkedIn.com Gurgaon, Sector 26 SHRM Research on SHRM Connect: Haryana 122002 community.shrm.org Phone +91.12.44200243 E-mail [email protected] United Arab Emirates Dubai Knowledge Village Dubai, UAE Phone +971.050.104.6330 E-mail [email protected] 16-0156 To order printed copies of this report, visit shrmstore.shrm.org or call 1-800-444-5006. 2 About This Research Report 5 Executive Summary -
Life History Strategies, Population Regulation, and Implications for Fisheries Management1
872 PERSPECTIVE / PERSPECTIVE Life history strategies, population regulation, and implications for fisheries management1 Kirk O. Winemiller Abstract: Life history theories attempt to explain the evolution of organism traits as adaptations to environmental vari- ation. A model involving three primary life history strategies (endpoints on a triangular surface) describes general pat- terns of variation more comprehensively than schemes that examine single traits or merely contrast fast versus slow life histories. It provides a general means to predict a priori the types of populations with high or low demographic resil- ience, production potential, and conformity to density-dependent regulation. Periodic (long-lived, high fecundity, high recruitment variation) and opportunistic (small, short-lived, high reproductive effort, high demographic resilience) strat- egies should conform poorly to models that assume density-dependent recruitment. Periodic-type species reveal greatest recruitment variation and compensatory reserve, but with poor conformity to stock–recruitment models. Equilibrium- type populations (low fecundity, large egg size, parental care) should conform better to assumptions of density- dependent recruitment, but have lower demographic resilience. The model’s predictions are explored relative to sustain- able harvest, endangered species conservation, supplemental stocking, and transferability of ecological indices. When detailed information is lacking, species ordination according to the triangular model provides qualitative -
Can More K-Selected Species Be Better Invaders?
Diversity and Distributions, (Diversity Distrib.) (2007) 13, 535–543 Blackwell Publishing Ltd BIODIVERSITY Can more K-selected species be better RESEARCH invaders? A case study of fruit flies in La Réunion Pierre-François Duyck1*, Patrice David2 and Serge Quilici1 1UMR 53 Ӷ Peuplements Végétaux et ABSTRACT Bio-agresseurs en Milieu Tropical ӷ CIRAD Invasive species are often said to be r-selected. However, invaders must sometimes Pôle de Protection des Plantes (3P), 7 chemin de l’IRAT, 97410 St Pierre, La Réunion, France, compete with related resident species. In this case invaders should present combina- 2UMR 5175, CNRS Centre d’Ecologie tions of life-history traits that give them higher competitive ability than residents, Fonctionnelle et Evolutive (CEFE), 1919 route de even at the expense of lower colonization ability. We test this prediction by compar- Mende, 34293 Montpellier Cedex, France ing life-history traits among four fruit fly species, one endemic and three successive invaders, in La Réunion Island. Recent invaders tend to produce fewer, but larger, juveniles, delay the onset but increase the duration of reproduction, survive longer, and senesce more slowly than earlier ones. These traits are associated with higher ranks in a competitive hierarchy established in a previous study. However, the endemic species, now nearly extinct in the island, is inferior to the other three with respect to both competition and colonization traits, violating the trade-off assumption. Our results overall suggest that the key traits for invasion in this system were those that *Correspondence: Pierre-François Duyck, favoured competition rather than colonization. CIRAD 3P, 7, chemin de l’IRAT, 97410, Keywords St Pierre, La Réunion Island, France. -
Recruitment, Dispersal, and Demographic Rescue in Spatially-Structured White-Tailed Ptarmigan Populations ’
The Condor 102:503-516 D The Cooper Ornithological Society Zoo0 RECRUITMENT, DISPERSAL, AND DEMOGRAPHIC RESCUE IN SPATIALLY-STRUCTURED WHITE-TAILED PTARMIGAN POPULATIONS ’ KATHY MARTIN Canadian Wildlife Service, 5421 Robertson Rd, RR I Delta, British Columbia, Canada, V4K 3N2, and Department of Forest Sciences, 2424 Main Mall, University of British Columbia, Vancouver, British Columbia, Canada, V6T 124, e-mail: [email protected] PETER B. STACEY Department of Biology, University of New Mexico, Albuquerque, NM 87131, e-mail: [email protected] CLAIT E. BRAUN* Colorado Division of Wildlife, 317 West Prospect Rd., Fort Collins, CO 80526, e-mail: [email protected] Abstract. We studiedrecruitment and dispersalof White-tailed Ptarmigan (Lagopus leu- curus) breeding in naturally fragmented alpine habitatsat four study sites in Colorado from 1987-1998. Almost all recruitment for both sexes, particularly females, was of birds pro- duced outside local populationsand also external to nearby studiedpopulations. Populations were more dependent on female recruitment than on male recruitment to sustainthem, and patterns of recruitment were not correlated with local survival of adults or production of young the previous year, except at one site for females. Over 95% of recruitswere yearlings. Breeding dispersal of adults, an infrequent but regular event, was also important to inter- population connectivity. Our data for multiple populationsallowed us to describemovement patterns among populations to assess consistency with conditions required for a -
Talent Acquisition Technology Ecosystem
Global Staffing and Recruitment Technology Talent Acquisition Technology Ecosystem February 15, 2018 | David Francis, Research Manager | [email protected] Talent Acquisition Technology Ecosystem | February 15, 2017 Contents Talent Acquisition Technology Ecosystem ........................................................................................................................................................... 2 Overview of an Ecosystem .................................................................................................................................................................................... 3 Systems of Record ................................................................................................................................................................................................ 8 Candidate Discovery ........................................................................................................................................................................................... 10 Candidate Assessment ........................................................................................................................................................................................ 14 Candidate Engagement ....................................................................................................................................................................................... 15 Candidate Verification ....................................................................................................................................................................................... -
Recruitment of Marine Invertebrates: the Role of Active Larval Choices and Early Mortality
Oecologia (Berl) (1982) 54:348-352 Oer Springer-Verlag 1982 Recruitment of Marine Invertebrates: the Role of Active Larval Choices and Early Mortality Michael J. Keough and Barbara J. Downes Department of Biological Sciences, University of California, Santa Barbara, Ca 93106, USA Summary. Spatial variation in the recruitment of sessile a reflection of the limitations of the observer. The number marine invertebrates with planktonic larvae may be derived of organisms passing through the fourth phase is termed from a number of sources: events within the plankton, recruitment, while the number passing to the third phase choices made by larvae at the time of settlement, and mor- is termed settlement. Recruitment is a composite of larval tality of juvenile organisms after settlement, but before a and juvenile stages, while settlement involves only larval census by an observer. These sources usually are not distin- stages. guished. It is important to distinguish between settlement and A study of the recruitment of four species of sessile recruitment. Non-random patterns of recruitment, such as invertebrates living on rock walls beneath a kelp canopy differences in the density of recruitment with height on the showed that both selection of microhabitats by settling shore (Underwood 1979) or differences in the density of larvae and predation by fish may be important. Two micro- recruitment with patch size (Jackson 1977; Keough 1982a), habitats were of interest; open, flat rock surfaces, and small or with microhabitat, may have two causes: (1) differential pits and crevices that act as refuges from fish predators. settlement, and (2), different probabilities of early mortality The polychaete Spirorbis eximus and the cyclostome in different parts of an organism's habitat. -
Herbivore Physiological Response to Predation Risk and Implications for Ecosystem Nutrient Dynamics
Herbivore physiological response to predation risk and implications for ecosystem nutrient dynamics Dror Hawlena and Oswald J. Schmitz1 School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511 Communicated by Thomas W. Schoener, University of California, Davis, CA, June 29, 2010 (received for review January 4, 2010) The process of nutrient transfer throughan ecosystem is an important lower the quantity of energy that can be allocated to production determinant of production, food-chain length, and species diversity. (20–23). Consequently, stress-induced constraints on herbivore The general view is that the rate and efficiency of nutrient transfer up production should lower the demand for N-rich proteins (24). the food chain is constrained by herbivore-specific capacity to secure Herbivores also have low capacity to store excess nutrients (24), N-rich compounds for survival and production. Using feeding trials and hence should seek plants with high digestible carbohydrate with artificial food, we show, however, that physiological stress- content to minimize the costs of ingesting and excreting excess N. response of grasshopper herbivores to spider predation risk alters the Such stress-induced shift in nutrient demand may be especially nature of the nutrient constraint. Grasshoppers facing predation risk important in terrestrial systems in which digestible carbohydrate had higher metabolic rates than control grasshoppers. Elevated represents a small fraction of total plant carbohydrate-C, and may metabolism accordingly increased requirements for dietary digestible be limiting even under risk-free conditions (25). Moreover, stress carbohydrate-C to fuel-heightened energy demands. Moreover, di- responses include break down of body proteins to produce glucose gestible carbohydrate-C comprises a small fraction of total plant (i.e., gluconeogenesis) (14), which requires excretion of N-rich tissue-C content, so nutrient transfer between plants and herbivores waste compounds (ammonia or primary amines) (26). -
Interspecific Killing Among Mammalian Carnivores
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Digital.CSIC vol. 153, no. 5 the american naturalist may 1999 Interspeci®c Killing among Mammalian Carnivores F. Palomares1,* and T. M. Caro2,² 1. Department of Applied Biology, EstacioÂn BioloÂgica de DonÄana, thought to act as keystone species in the top-down control CSIC, Avda. MarõÂa Luisa s/n, 41013 Sevilla, Spain; of terrestrial ecosystems (Terborgh and Winter 1980; Ter- 2. Department of Wildlife, Fish, and Conservation Biology and borgh 1992; McLaren and Peterson 1994). One factor af- Center for Population Biology, University of California, Davis, fecting carnivore populations is interspeci®c killing by California 95616 other carnivores (sometimes called intraguild predation; Submitted February 9, 1998; Accepted December 11, 1998 Polis et al. 1989), which has been hypothesized as having direct and indirect effects on population and community structure that may be more complex than the effects of either competition or predation alone (see, e.g., Latham 1952; Rosenzweig 1966; Mech 1970; Polis and Holt 1992; abstract: Interspeci®c killing among mammalian carnivores is Holt and Polis 1997). Currently, there is renewed interest common in nature and accounts for up to 68% of known mortalities in some species. Interactions may be symmetrical (both species kill in intraguild predation from a conservation standpoint each other) or asymmetrical (one species kills the other), and in since top predator removal is thought to release other some interactions adults of one species kill young but not adults of predator populations with consequences for lower trophic the other.