1
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van den Berg CP, Santon M, Endler JA, Drummond L, Dawson BR, Santiago C, Weber N, Cheney KL. Chemical defences indicate bold colour patterns with reduced variability in aposematic nudibranchs. Proc Biol Sci 2024; 291:20240953. [PMID: 39013421 PMCID: PMC11251778 DOI: 10.1098/rspb.2024.0953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 05/31/2024] [Accepted: 05/31/2024] [Indexed: 07/18/2024] Open
Abstract
The selective factors that shape phenotypic diversity in prey communities with aposematic animals are diverse and coincide with similar diversity in the strength of underlying secondary defences. However, quantitative assessments of colour pattern variation and the strength of chemical defences in assemblages of aposematic species are lacking. We quantified colour pattern diversity using quantitative colour pattern analysis (QCPA) in 13 dorid nudibranch species (Infraorder: Doridoidei) that varied in the strength of their chemical defences. We accounted for the physiological properties of a potential predator's visual system (a triggerfish, Rhinecanthus aculeatus) and modelled the appearance of nudibranchs from multiple viewing distances (2 and 10 cm). We identified distinct colour pattern properties associated with the presence and strength of chemical defences. Specifically, increases in chemical defences indicated increases in colour pattern boldness (i.e. visual contrast elicited via either or potentially coinciding chromatic, achromatic and/or spatial contrast). Colour patterns were also less variable among species with chemical defences when compared to undefended species. Our results indicate correlations between secondary defences and diverse, bold colouration while showing that chemical defences coincide with decreased colour pattern variability among species. Our study suggests that complex spatiochromatic properties of colour patterns perceived by potential predators can be used to make inferences on the presence and strength of chemical defences.
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Affiliation(s)
- Cedric P. van den Berg
- Marine Sensory Ecology Group, School of the Environment, The University of Queensland, Brisbane4072, Australia
- Ecology of Vision Laboratory, School of Biological Sciences, University of Bristol, BristolBS8 1TQ, UK
| | - Matteo Santon
- Ecology of Vision Laboratory, School of Biological Sciences, University of Bristol, BristolBS8 1TQ, UK
| | - John A. Endler
- Zoology and Ecology, Tropical Environments Sciences, College of Science & Engineering, James Cook University, Cairns, QLD4878, Australia
| | - Leon Drummond
- Marine Sensory Ecology Group, School of the Environment, The University of Queensland, Brisbane4072, Australia
| | - Bethany R. Dawson
- Marine Sensory Ecology Group, School of the Environment, The University of Queensland, Brisbane4072, Australia
| | - Carl Santiago
- Marine Sensory Ecology Group, School of the Environment, The University of Queensland, Brisbane4072, Australia
| | - Nathalie Weber
- Faculty of Biology and Medicine, School of Biological Sciences, The University of Lausanne, Lausanne1015, Switzerland
| | - Karen L. Cheney
- Marine Sensory Ecology Group, School of the Environment, The University of Queensland, Brisbane4072, Australia
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2
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Heerwig OT, Jain-Schlaepfer SMR, Sherratt TN, Kikuchi DW. Effects of predator associative learning and innate aversion on mimicry complexes. Evol Ecol 2023. [DOI: 10.1007/s10682-023-10238-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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3
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Scaramangas A, Broom M. Aposematic signalling in prey-predator systems: determining evolutionary stability when prey populations consist of a single species. J Math Biol 2022; 85:13. [PMID: 35870017 PMCID: PMC9308619 DOI: 10.1007/s00285-022-01762-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 05/11/2022] [Accepted: 05/21/2022] [Indexed: 11/25/2022]
Abstract
Aposematism is the signalling of a defence for the deterrence of predators. We presently focus on aposematic organisms that exhibit chemical defences, which are usually signalled by some type of brightly coloured skin pigmentation (as is the case with poison frog species of the Dendrobatidae family), although our treatment is likely transferable to other forms of secondary defence. This setup is not only a natural one to consider but also opens up the possibility for rich mathematical modelling: the strength of aposematic traits (signalling and defence) can be unambiguously realised using variables that are continuously quantifiable, independent from one another and which together define a two-dimensional strategy space wherein the aposematic behaviour of any one organism can be represented by a single point. We presently develop an extensive mathematical model in which we explore the joint co-evolution of aposematic traits within the context of evolutionary stability. Even though empirical and model-based studies are conflicting regarding how aposematic traits are related to one another in nature, the majority of works allude to a positive correlation. We presently suggest that both positively and negatively correlated combinations of traits can achieve evolutionarily stable outcomes and further, that for a given level of signal strength there can be more than one optimal level of defence. Our findings are novel and pertinent to a sizeable body of physical evidence, which we discuss.
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Affiliation(s)
| | - Mark Broom
- City University of London, London, EC1V 0HB, UK
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4
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Sculfort O, Maisonneuve L, Elias M, Aubier TG, Llaurens V. Uncovering the effects of Müllerian mimicry on the evolution of conspicuousness in colour patterns. OIKOS 2022. [DOI: 10.1111/oik.08680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ombeline Sculfort
- Inst. de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne‐Univ., EPHE, Univ. des Antilles Paris France
- Molécules de Communication et Adaptations des Micro‐organismes (MCAM), Muséum National d'Histoire Naturelle, CNRS Paris France
- Laboratoire Écologie, Évolution, Interactions des Systèmes Amazoniens (LEEISA), Univ. de Guyane, CNRS, IFREMER Cayenne France
| | - Ludovic Maisonneuve
- Inst. de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne‐Univ., EPHE, Univ. des Antilles Paris France
| | - Marianne Elias
- Inst. de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne‐Univ., EPHE, Univ. des Antilles Paris France
| | | | - Violaine Llaurens
- Inst. de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne‐Univ., EPHE, Univ. des Antilles Paris France
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5
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Kikuchi DW, Barfield M, Herberstein ME, Mappes J, Holt RD. The Effect of Predator Population Dynamics on Batesian Mimicry Complexes. Am Nat 2022; 199:406-419. [DOI: 10.1086/718162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- David W. Kikuchi
- Wissenschaftskolleg zu Berlin, Wallotstraße 19, Berlin, Germany
- Evolutionary Biology, Universität Bielefeld, Konsequez 45, 33615 Bielefeld, Germany
| | - Michael Barfield
- Department of Biology, University of Florida, Gainesville, Florida 32611
| | - Marie E. Herberstein
- Wissenschaftskolleg zu Berlin, Wallotstraße 19, Berlin, Germany
- Department of Biological Sciences, Macquarie University, North Ryde, New South Wales 2109, Australia
| | - Johanna Mappes
- Wissenschaftskolleg zu Berlin, Wallotstraße 19, Berlin, Germany
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, Helsinki University, Helsinki, Finland; and Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä FI-40014, Finland
| | - Robert D. Holt
- Wissenschaftskolleg zu Berlin, Wallotstraße 19, Berlin, Germany
- Department of Biology, University of Florida, Gainesville, Florida 32611
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6
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Kikuchi DW, Herberstein ME, Barfield M, Holt RD, Mappes J. Why aren't warning signals everywhere? On the prevalence of aposematism and mimicry in communities. Biol Rev Camb Philos Soc 2021; 96:2446-2460. [PMID: 34128583 DOI: 10.1111/brv.12760] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 05/27/2021] [Accepted: 06/01/2021] [Indexed: 11/29/2022]
Abstract
Warning signals are a striking example of natural selection present in almost every ecological community - from Nordic meadows to tropical rainforests, defended prey species and their mimics ward off potential predators before they attack. Yet despite the wide distribution of warning signals, they are relatively scarce as a proportion of the total prey available, and more so in some biomes than others. Classically, warning signals are thought to be governed by positive density-dependent selection, i.e. they succeed better when they are more common. Therefore, after surmounting this initial barrier to their evolution, it is puzzling that they remain uncommon on the scale of the community. Here, we explore factors likely to determine the prevalence of warning signals in prey assemblages. These factors include the nature of prey defences and any constraints upon them, the behavioural interactions of predators with different prey defences, the numerical responses of predators governed by movement and reproduction, the diversity and abundance of undefended alternative prey and Batesian mimics in the community, and variability in other ecological circumstances. We also discuss the macroevolution of warning signals. Our review finds that we have a basic understanding of how many species in some taxonomic groups have warning signals, but very little information on the interrelationships among population abundances across prey communities, the diversity of signal phenotypes, and prey defences. We also have detailed knowledge of how a few generalist predator species forage in artificial laboratory environments, but we know much less about how predators forage in complex natural communities with variable prey defences. We describe how empirical work to address each of these knowledge gaps can test specific hypotheses for why warning signals exhibit their particular patterns of distribution. This will help us to understand how behavioural interactions shape ecological communities.
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Affiliation(s)
- David W Kikuchi
- Wissenschaftskolleg zu Berlin, Wallotstraße 19, Berlin, Germany.,Evolutionary Biology, Universität Bielefeld, Konsequez 45, Bielefeld, 33615, Germany
| | - Marie E Herberstein
- Wissenschaftskolleg zu Berlin, Wallotstraße 19, Berlin, Germany.,Department of Biological Sciences, Macquarie University, North Ryde, New South Wales, 2109, Australia
| | - Michael Barfield
- Department of Biology, University of Florida, Gainesville, FL, 32611-8525, U.S.A
| | - Robert D Holt
- Department of Biology, University of Florida, Gainesville, FL, 32611-8525, U.S.A
| | - Johanna Mappes
- Wissenschaftskolleg zu Berlin, Wallotstraße 19, Berlin, Germany.,Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, Helsinki University, Helsinki, Finland.,Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, FI-40014, Finland
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7
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Brejcha J, Tureček P, Kleisner K. Perception-driven dynamics of mimicry based on attractor field model. Interface Focus 2021; 11:20200052. [PMID: 34055303 PMCID: PMC8086919 DOI: 10.1098/rsfs.2020.0052] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2021] [Indexed: 01/02/2023] Open
Abstract
We provide a formal account of an interface that bridges two different levels of dynamic processes manifested by mimicry: prey-prey interactions and predators' perception. Mimicry is a coevolutionary process between an animate selective agent and at least two similar organisms selected by agent's perception-driven actions. Attractor field model explains perceived similarity of forms by noting that in both human and animal cognition, morphologically intermediate forms are more likely to be perceived as belonging to rare rather than abundant forms. We formalize this model in terms of predators' perception space deformation using numerical simulations and argue that the probability of confusion between similar species creates pressure on the perception space, which in turn leads to inflation of regions of perception space with high density of species representations. Such inflation causes increased discrimination between species by a predator, which implies that adaptive mimicry could initially emerge more easily among atypical species because they do not need the same level of similarity to the model. We provide a theoretical instrument to conceptualize interdependence between objective measurable matrices and perceived matrices of the same external reality. We believe that our framework leads to a more precise understanding of the evolution of mimicry.
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Affiliation(s)
- Jindřich Brejcha
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, Praha 2 128 00, Czech Republic
| | - Petr Tureček
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, Praha 2 128 00, Czech Republic
- Center for Theoretical Study, Charles University and Czech Academy of Sciences, Jilská 1, Prague 1 110 00, Czech Republic
| | - Karel Kleisner
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, Praha 2 128 00, Czech Republic
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8
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White TE, Umbers KDL. Meta-analytic evidence for quantitative honesty in aposematic signals. Proc Biol Sci 2021; 288:20210679. [PMID: 33906408 PMCID: PMC8080005 DOI: 10.1098/rspb.2021.0679] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 04/08/2021] [Indexed: 12/30/2022] Open
Abstract
The combined use of noxious chemical defences and conspicuous warning colours is a ubiquitous anti-predator strategy. That such signals advertise the presence of defences is inherent to their function, but their predicted potential for quantitative honesty-the positive scaling of signal salience with the strength of protection-is the subject of enduring debate. Here, we systematically synthesized the available evidence to test this prediction using meta-analysis. We found evidence for a positive correlation between warning colour expression and the extent of chemical defences across taxa. Notably, this relationship held at all scales; among individuals, populations and species, though substantial between-study heterogeneity remains unexplained. Consideration of the design of signals revealed that all visual features, from colour to contrast, were equally informative of the extent of prey defence. Our results affirm a central prediction of honesty-based models of signal function and narrow the scope of possible mechanisms shaping the evolution of aposematism. They suggest diverse pathways to the encoding and exchange of information, while highlighting the need for deeper knowledge of the ecology of chemical defences to enrich our understanding of this widespread anti-predator adaptation.
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Affiliation(s)
- Thomas E. White
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2106, Australia
| | - Kate D. L. Umbers
- School of Science, Western Sydney University, Penrith, New South Wales 2751, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia
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9
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Aubier TG, Sherratt TN. State-Dependent Decision-Making by Predators and Its Consequences for Mimicry. Am Nat 2020; 196:E127-E144. [PMID: 33064589 DOI: 10.1086/710568] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractThe mimicry of one species by another provides one of the most celebrated examples of evolution by natural selection. Edible Batesian mimics deceive predators into believing they may be defended, whereas defended Müllerian mimics have evolved a shared warning signal, more rapidly educating predators to avoid them. However, it may benefit hungry predators to attack defended prey, while the benefits of learning about unfamiliar prey depends on the future value of this information. Previous energetic state-dependent models of predator foraging behavior have assumed complete knowledge, while informational state-dependent models have assumed fixed levels of hunger. Here, we identify the optimal decision rules of predators accounting for both energetic and informational states. We show that the nature of mimicry is qualitatively and quantitatively affected by both sources of state dependence. Associative learning weakens the extent of parasitic mimicry by edible prey because naive predators often attack defended models. More importantly, mimicry among equally highly defended prey may be parasitic or mutualistic depending on the ecological context (e.g., the source of mimics and the abundance of alternative prey). Finally, mimicry by prey with intermediate defenses corresponds to Batesian or Müllerian mimicry depending on whether the mimic is profitable to attack by hungry predators, but it is not a special case of mimicry.
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10
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Wilkins L, Osorio D. Object colours, material properties and animal signals. ACTA ACUST UNITED AC 2019; 222:jeb.204487. [PMID: 31570511 DOI: 10.1242/jeb.204487] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Accepted: 09/26/2019] [Indexed: 11/20/2022]
Abstract
Humans and other animals often use colour to recognise objects regardless of their context - as a measure of material properties rather than of their contrast with a background. Most work on visual communication signals is, however, concerned with colour differences, typically scaled by just noticeable differences (JNDs). Here, we move from the prevailing physiological framework to understand what a given colour or type of colour might tell an animal about an object. To this end, we consider the properties of object colour solids, which represent the colour gamut of reflective materials for a given type of animal eye. The geometry of colour solids reveals general relationships between colours and object properties, which can explain why certain colours are significant to animals, and hence evolve as signals. We define a measure of colour vividness, such that points on the surface are maximally vivid and the 'grey' centre is minimally vivid. We show that a vivid colour for one animal is likely to be vivid for others, and highly vivid colours are less easily mimicked than less vivid colours. Furthermore, vivid colours such as black, white, red and blue, as well as pale colours and certain unsaturated shades, are produced by pure or orderly materials. Such materials are created and maintained against entropic processes. Vivid colours are therefore indicative of ecological affordance or biological function, so it is valuable to have low-level psychological biases towards these colours regardless of any specific significance they might have to the receiver.
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Affiliation(s)
- Lucas Wilkins
- Department of Zoology, University of Oxford, Oxford OX1 3SZ, UK .,School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Daniel Osorio
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
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11
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Anderson B, de Jager ML. Natural selection in mimicry. Biol Rev Camb Philos Soc 2019; 95:291-304. [PMID: 31663254 DOI: 10.1111/brv.12564] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/27/2019] [Accepted: 10/02/2019] [Indexed: 11/29/2022]
Abstract
Biological mimicry has served as a salient example of natural selection for over a century, providing us with a dazzling array of very different examples across many unrelated taxa. We provide a conceptual framework that brings together apparently disparate examples of mimicry in a single model for the purpose of comparing how natural selection affects models, mimics and signal receivers across different interactions. We first analyse how model-mimic resemblance likely affects the fitness of models, mimics and receivers across diverse examples. These include classic Batesian and Müllerian butterfly systems, nectarless orchids that mimic Hymenoptera or nectar-producing plants, caterpillars that mimic inert objects unlikely to be perceived as food, plants that mimic abiotic objects like carrion or dung and aggressive mimicry where predators mimic food items of their own prey. From this, we construct a conceptual framework of the selective forces that form the basis of all mimetic interactions. These interactions between models, mimics and receivers may follow four possible evolutionary pathways in terms of the direction of selection resulting from model-mimic resemblance. Two of these pathways correspond to the selective pressures associated with what is widely regarded as Batesian and Müllerian mimicry. The other two pathways suggest mimetic interactions underpinned by distinct selective pressures that have largely remained unrecognized. Each pathway is characterized by theoretical differences in how model-mimic resemblance influences the direction of selection acting on mimics, models and signal receivers, and the potential for consequent (co)evolutionary relationships between these three protagonists. The final part of this review describes how selective forces generated through model-mimic resemblance can be opposed by the basic ecology of interacting organisms and how those forces may affect the symmetry, strength and likelihood of (co)evolution between the three protagonists within the confines of the four broad evolutionary possibilities. We provide a clear and pragmatic visualization of selection pressures that portrays how different mimicry types may evolve. This conceptual framework provides clarity on how different selective forces acting on mimics, models and receivers are likely to interact and ultimately shape the evolutionary pathways taken by mimetic interactions, as well as the constraints inherent within these interactions.
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Affiliation(s)
- Bruce Anderson
- Botany and Zoology Department, Stellenbosch University, Matieland, 7602, South Africa
| | - Marinus L de Jager
- Botany and Zoology Department, Stellenbosch University, Matieland, 7602, South Africa
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12
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Briolat ES, Zagrobelny M, Olsen CE, Blount JD, Stevens M. No evidence of quantitative signal honesty across species of aposematic burnet moths (Lepidoptera: Zygaenidae). J Evol Biol 2018; 32:31-48. [PMID: 30317689 PMCID: PMC6378400 DOI: 10.1111/jeb.13389] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 10/03/2018] [Accepted: 10/09/2018] [Indexed: 11/30/2022]
Abstract
Many defended species use conspicuous visual warning signals to deter potential predators from attacking. Traditional theory holds that these signals should converge on similar forms, yet variation in visual traits and the levels of defensive chemicals is common, both within and between species. It is currently unclear how the strength of signals and potency of defences might be related: conflicting theories suggest that aposematic signals should be quantitatively honest, or, in contrast, that investment in one component should be prioritized over the other, while empirical tests have yielded contrasting results. Here, we advance this debate by examining the relationship between defensive chemicals and signal properties in a family of aposematic Lepidoptera, accounting for phylogenetic relationships and quantifying coloration from the perspective of relevant predators. We test for correlations between toxin levels and measures of wing colour across 14 species of day‐flying burnet and forester moths (Lepidoptera: Zygaenidae), protected by highly aversive cyanogenic glucosides, and find no clear evidence of quantitative signal honesty. Significant relationships between toxin levels and coloration vary between sexes and sampling years, and several trends run contrary to expectations for signal honesty. Although toxin concentration is positively correlated with increasing luminance contrast in forewing pattern in 1 year, higher toxin levels are also associated with paler and less chromatically salient markings, at least in females, in another year. Our study also serves to highlight important factors, including sex‐specific trends and seasonal variation, that should be accounted for in future work on signal honesty in aposematic species.
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Affiliation(s)
- Emmanuelle S Briolat
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn, UK
| | - Mika Zagrobelny
- Plant Biochemistry Laboratory and Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Carl E Olsen
- Plant Biochemistry Laboratory and Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jonathan D Blount
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn, UK
| | - Martin Stevens
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn, UK
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13
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Holen ØH, Johnstone RA. Reciprocal mimicry: kin selection can drive defended prey to resemble their Batesian mimics. Proc Biol Sci 2018; 285:rspb.2018.1149. [PMID: 30381376 DOI: 10.1098/rspb.2018.1149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 10/09/2018] [Indexed: 11/12/2022] Open
Abstract
Established mimicry theory predicts that Batesian mimics are selected to resemble their defended models, while models are selected to become dissimilar from their mimics. However, this theory has mainly considered individual selection acting on solitary organisms such as adult butterflies. Although Batesian mimicry of social insects is common, the few existing applications of kin selection theory to mimicry have emphasized relatedness among mimics rather than among models. Here, we present a signal detection model of Batesian mimicry in which the population of defended model prey is kin structured. Our analysis shows for most of parameter space that increased average dissimilarity from mimics has a twofold group-level cost for the model prey: it attracts more predators and these adopt more aggressive attack strategies. When mimetic resemblance and local relatedness are sufficiently high, such costs acting in the local neighbourhood may outweigh the individual benefits of dissimilarity, causing kin selection to drive the models to resemble their mimics. This requires model prey to be more common than mimics and/or well-defended, the conditions under which Batesian mimicry is thought most successful. Local relatedness makes defended prey easier targets for Batesian mimicry and is likely to stabilize the mimetic relationship over time.
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Affiliation(s)
- Øistein Haugsten Holen
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, PO Box 1050 Blindern, 0316 Oslo, Norway
| | - Rufus A Johnstone
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
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14
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Akcali CK, Kikuchi DW, Pfennig DW. Coevolutionary arms races in Batesian mimicry? A test of the chase-away hypothesis. Biol J Linn Soc Lond 2018. [DOI: 10.1093/biolinnean/bly075] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Christopher K Akcali
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
- North Carolina Museum of Natural Sciences, Raleigh, NC, USA
| | - David W Kikuchi
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, USA
| | - David W Pfennig
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
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15
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Aubier TG, Elias M, Llaurens V, Chazot N. Mutualistic mimicry enhances species diversification through spatial segregation and extension of the ecological niche space. Evolution 2017; 71:826-844. [DOI: 10.1111/evo.13182] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 01/06/2017] [Indexed: 11/28/2022]
Affiliation(s)
- Thomas G. Aubier
- Centre d'Ecologie Fonctionnelle et Evolutive; CEFE - UMR 5175 - CNRS, Université de Montpellier, EPHE, Université Paul Valéry; 1919 route de Mende, F-34293 Montpellier 5 France
- Institut de Systématique, Evolution, Biodiversité, ISYEB - UMR 7205 - CNRS, MNHN, UPMC, EPHE, Muséum National d'Histoire Naturelle; Sorbonne Universités; 57 rue Cuvier, CP50 F-75005 Paris France
| | - Marianne Elias
- Institut de Systématique, Evolution, Biodiversité, ISYEB - UMR 7205 - CNRS, MNHN, UPMC, EPHE, Muséum National d'Histoire Naturelle; Sorbonne Universités; 57 rue Cuvier, CP50 F-75005 Paris France
| | - Violaine Llaurens
- Institut de Systématique, Evolution, Biodiversité, ISYEB - UMR 7205 - CNRS, MNHN, UPMC, EPHE, Muséum National d'Histoire Naturelle; Sorbonne Universités; 57 rue Cuvier, CP50 F-75005 Paris France
| | - Nicolas Chazot
- Institut de Systématique, Evolution, Biodiversité, ISYEB - UMR 7205 - CNRS, MNHN, UPMC, EPHE, Muséum National d'Histoire Naturelle; Sorbonne Universités; 57 rue Cuvier, CP50 F-75005 Paris France
- Department of Biology; Lund University; Lund Sweden
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16
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Arias M, Meichanetzoglou A, Elias M, Rosser N, de-Silva DL, Nay B, Llaurens V. Variation in cyanogenic compounds concentration within a Heliconius butterfly community: does mimicry explain everything? BMC Evol Biol 2016; 16:272. [PMID: 27978820 PMCID: PMC5160018 DOI: 10.1186/s12862-016-0843-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 11/26/2016] [Indexed: 11/10/2022] Open
Abstract
Background Aposematic species advertise their unpalatability using warning signals such as striking coloration. Given that predators need to sample aposematic prey to learn that they are unprofitable, prey with similar warning signals share the cost of predator learning. This reduction in predation risk drives evolutionary convergence of warning signals among chemically defended prey (Müllerian mimicry). Whether such warning signal convergence is associated to similar defence levels among co-mimics is still an open question that has rarely been tested in wild populations. We quantified variation in cyanide-based (CN) chemical protection in wild caught individuals of eight aposematic Heliconius butterfly species belonging to four sympatric mimicry rings. We then tested for correlations between chemical protection and ecological species-specific traits. Results We report significant differences in CN concentrations both within and between sympatric species, even when accounting for the phylogeny, and within and between mimicry rings, even after considering inter-specific variation. We found significant correlations between CN concentration and both hostplant specialization and gregarious behaviour in adults and larvae. However, differences in CN concentrations were not significantly linked to mimicry ring abundance, although the two most toxic species did belong to the rarest mimicry ring. Conclusions Our results suggest that mimicry can explain the variation in the levels of chemical defence to a certain extent, although other ecological factors are also relevant to the evolution of such variability. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0843-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mónica Arias
- Institut Systématique, Evolution, Biodiversité, UMR 7205 MNHN-CNRS-EPHE-UPMC- Sorbonne Universités, Muséum National d'Histoire Naturelle, Bâtiment d'entomologie, CP050, 57 rue Cuvier, 75005, Paris, France.
| | - Aimilia Meichanetzoglou
- Institut Systématique, Evolution, Biodiversité, UMR 7205 MNHN-CNRS-EPHE-UPMC- Sorbonne Universités, Muséum National d'Histoire Naturelle, Bâtiment d'entomologie, CP050, 57 rue Cuvier, 75005, Paris, France.,Unité Molécules de Communication et Adaptation des Micro-organismes, UMR 7245 MNHN-CNRS, Sorbonne Universités, Muséum National d'Histoire Naturelle and CNRS, 57 rue Cuvier, CP 54, 75005, Paris, France
| | - Marianne Elias
- Institut Systématique, Evolution, Biodiversité, UMR 7205 MNHN-CNRS-EPHE-UPMC- Sorbonne Universités, Muséum National d'Histoire Naturelle, Bâtiment d'entomologie, CP050, 57 rue Cuvier, 75005, Paris, France
| | - Neil Rosser
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK
| | - Donna Lisa de-Silva
- Institut Systématique, Evolution, Biodiversité, UMR 7205 MNHN-CNRS-EPHE-UPMC- Sorbonne Universités, Muséum National d'Histoire Naturelle, Bâtiment d'entomologie, CP050, 57 rue Cuvier, 75005, Paris, France
| | - Bastien Nay
- Unité Molécules de Communication et Adaptation des Micro-organismes, UMR 7245 MNHN-CNRS, Sorbonne Universités, Muséum National d'Histoire Naturelle and CNRS, 57 rue Cuvier, CP 54, 75005, Paris, France
| | - Violaine Llaurens
- Institut Systématique, Evolution, Biodiversité, UMR 7205 MNHN-CNRS-EPHE-UPMC- Sorbonne Universités, Muséum National d'Histoire Naturelle, Bâtiment d'entomologie, CP050, 57 rue Cuvier, 75005, Paris, France
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Kikuchi DW, Sherratt TN. Costs of Learning and the Evolution of Mimetic Signals. Am Nat 2015; 186:321-32. [DOI: 10.1086/682371] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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18
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Summers K, Speed MP, Blount JD, Stuckert AMM. Are aposematic signals honest? A review. J Evol Biol 2015; 28:1583-99. [DOI: 10.1111/jeb.12676] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 06/08/2015] [Accepted: 06/11/2015] [Indexed: 01/22/2023]
Affiliation(s)
- K. Summers
- Department of Biology; East Carolina University; Greenville NC USA
| | - M. P. Speed
- Department of Evolution, Ecology, and Behaviour; University of Liverpool; Liverpool UK
| | - J. D. Blount
- Centre for Ecology and Conservation, Biosciences; University of Exeter; Penryn UK
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19
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Weldon PJ, Burghardt GM. Evolving détente: the origin of warning signals via concurrent reciprocal selection. Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12565] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Paul J. Weldon
- Smithsonian Conservation Biology Institute; National Zoological Park; 1500 Remount Road Front Royal VA 22630 USA
| | - Gordon M. Burghardt
- Departments of Psychology and Ecology & Evolutionary Biology; University of Tennessee; 1404 Circle Drive Knoxville TN 37996-0900 USA
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20
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Model toxin level does not directly influence the evolution of mimicry in the salamander Plethodon cinereus. Evol Ecol 2015. [DOI: 10.1007/s10682-015-9765-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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21
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Kraemer AC, Serb JM, Adams DC. Batesian mimics influence the evolution of conspicuousness in an aposematic salamander. J Evol Biol 2015; 28:1016-23. [PMID: 25786622 DOI: 10.1111/jeb.12622] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 03/02/2015] [Indexed: 11/28/2022]
Abstract
Conspicuousness, or having high contrast relative to the surrounding background, is a common feature of unpalatable species. Several hypotheses have been proposed to explain the occurrence of conspicuousness, and while most involve the role of conspicuousness as a direct signal of unpalatability to potential predators, one hypothesis suggests that exaggerated conspicuousness may evolve in unpalatable species to reduce predator confusion with palatable species (potential Batesian mimics). This hypothesis of antagonistic coevolution between palatable and unpalatable species hinges on the 'cost of conspicuousness', in which conspicuousness increases the likelihood of predation more in palatable species than in unpalatable species. Under this mimicry scenario, four patterns are expected: (i) mimics will more closely resemble local models than models from other localities, (ii) there will be a positive relationship between mimic and model conspicuousness, (iii) models will be more conspicuous in the presence of mimics, and (iv) when models and mimics differ in conspicuousness, mimics will be less conspicuous than models. We tested these predictions in the salamander mimicry system involving Notophthalmus viridescens (model) and one colour morph of Plethodon cinereus (mimic). All predictions were supported, indicating that selection for Batesian mimicry not only influences the evolution of mimics, but also the evolution of the models they resemble. These findings indicate that mimicry plays a large role in the evolution of model warning signals, particularly influencing the evolution of conspicuousness.
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Affiliation(s)
- A C Kraemer
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, USA
| | - J M Serb
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, USA
| | - D C Adams
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, USA
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22
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Andersson M. Aposematism and crypsis in a rodent: antipredator defence of the Norwegian lemming. Behav Ecol Sociobiol 2015. [DOI: 10.1007/s00265-014-1868-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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23
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Wheeler CA, Millar JG, Cardé RT. Multimodal signal interactions in the ladybeetle, Hippodamia convergens, aposematic system. CHEMOECOLOGY 2014. [DOI: 10.1007/s00049-014-0181-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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24
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Speed MP, Franks DW. Antagonistic evolution in an aposematic predator-prey signaling system. Evolution 2014; 68:2996-3007. [PMID: 25132560 DOI: 10.1111/evo.12498] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 07/02/2014] [Indexed: 11/29/2022]
Abstract
Warning signals within species, such as the bright colors of chemically defended animals, are usually considered mutualistic, monomorphic traits. Such a view is however increasingly at odds with the growing empirical literature, showing nontrivial levels of signal variation within prey populations. Key to understanding this variation, we argue, could be a recognition that toxicity levels frequently vary within populations because of environmental heterogeneity. Inequalities in defense may undermine mutualistic monomorphic signaling, causing evolutionary antagonism between loci that determine appearance of less well-defended and better defended prey forms within species. In this article, we apply a stochastic model of evolved phenotypic plasticity to the evolution of prey signals. We show that when toxicity levels vary, then antagonistic interactions can lead to evolutionary conflict between alleles at different signaling loci, causing signal evolution, "red queen-like" evolutionary chase, and one or more forms of signaling equilibria. A key prediction is that variation in the way that predators use information about toxicity levels in their attack behaviors profoundly affects the evolutionary characteristics of the prey signaling systems. Environmental variation is known to cause variation in many qualities that organisms signal; our approach may therefore have application to other signaling systems.
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Affiliation(s)
- Michael P Speed
- Department of Evolution, Ecology and Behaviour, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, United Kingdom.
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25
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Kikuchi DW, Pfennig DW. Imperfect mimicry and the limits of natural selection. QUARTERLY REVIEW OF BIOLOGY 2014; 88:297-315. [PMID: 24552099 DOI: 10.1086/673758] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Mimicry--when one organism (the mimic) evolves a phenotypic resemblance to another (the model) due to selective benefits--is widely used to illustrate natural selection's power to generate adaptations. However, many putative mimics resemble their models imprecisely, and such imperfect mimicry represents a specific challenge to mimicry theory and a general one to evolutionary theory. Here, we discuss 11 nonmutually exclusive hypotheses for imperfect mimicry. We group these hypotheses according to whether imperfect mimicry reflects: an artifact of human perception, which is not shared by any naturally occurring predators and therefore is not truly an instance of imperfect mimicry; genetic, developmental or time-lag constraints, which (temporarily) prevent a response to selection for perfect mimicry; relaxed selection, where imperfect mimicry is as adaptive as perfect mimicry; or tradeoffs, where imperfect mimicry is (locally) more adaptive than perfect mimicry. We find that the relaxed selection hypothesis has garnered the most support. However, because only a few study systems have thus far been comprehensively evaluated, the relative contributions of the various hypotheses toward explaining the evolution of imperfect mimicry remain unclear. Ultimately, clarifying why imperfect mimicry exists should provide critical insights into the limits of natural selection in producing complex adaptations.
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Affiliation(s)
- David W Kikuchi
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA.
| | - David W Pfennig
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
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26
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Lehmann KDS, Goldman BW, Dworkin I, Bryson DM, Wagner AP. From cues to signals: evolution of interspecific communication via aposematism and mimicry in a predator-prey system. PLoS One 2014; 9:e91783. [PMID: 24614755 PMCID: PMC3948874 DOI: 10.1371/journal.pone.0091783] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 02/14/2014] [Indexed: 11/19/2022] Open
Abstract
Current theory suggests that many signaling systems evolved from preexisting cues. In aposematic systems, prey warning signals benefit both predator and prey. When the signal is highly beneficial, a third species often evolves to mimic the toxic species, exploiting the signaling system for its own protection. We investigated the evolutionary dynamics of predator cue utilization and prey signaling in a digital predator-prey system in which prey could evolve to alter their appearance to mimic poison-free or poisonous prey. In predators, we observed rapid evolution of cue recognition (i.e. active behavioral responses) when presented with sufficiently poisonous prey. In addition, active signaling (i.e. mimicry) evolved in prey under all conditions that led to cue utilization. Thus we show that despite imperfect and dishonest signaling, given a high cost of consuming poisonous prey, complex systems of interspecific communication can evolve via predator cue recognition and prey signal manipulation. This provides evidence supporting hypotheses that cues may serve as stepping-stones in the evolution of more advanced communication and signaling systems that incorporate information about the environment.
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Affiliation(s)
- Kenna D. S. Lehmann
- Department of Zoology, Michigan State University, East Lansing, Michigan, United States of America
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
- Program in Ecology, Evolutionary Biology, and Behavior, Michigan State University, East Lansing, Michigan, United States of America
| | - Brian W. Goldman
- Department of Computer Science and Engineering, Michigan State University, East Lansing, Michigan, United States of America
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
| | - Ian Dworkin
- Department of Zoology, Michigan State University, East Lansing, Michigan, United States of America
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
- Program in Ecology, Evolutionary Biology, and Behavior, Michigan State University, East Lansing, Michigan, United States of America
| | - David M. Bryson
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
| | - Aaron P. Wagner
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
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27
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Kraemer AC, Adams DC. Predator perception of Batesian mimicry and conspicuousness in a salamander. Evolution 2013; 68:1197-206. [PMID: 24274647 DOI: 10.1111/evo.12325] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 11/12/2013] [Indexed: 11/28/2022]
Abstract
In Batesian mimicry a palatable mimic deceives predators by resembling an unpalatable model. The evolution of Batesian mimicry relies on the visual capabilities of the potential predators, as prey detection provides the selective force driving evolutionary change. We compared the visual capabilities of several potential predators to test predictions stemming from the hypothesis of Batesian mimicry between two salamanders: the model species Notophthalmus viridescens, and polymorphic mimic, Plethodon cinereus. First, we found mimicry to be restricted to coloration, but not brightness. Second, only bird predators appeared able to discriminate between the colors of models and nonmimic P. cinereus. Third, estimates of salamander conspicuousness were background dependent, corresponding to predictions only for backgrounds against which salamanders are most active. These results support the hypothesis that birds influence the evolution of Batesian mimicry in P. cinereus, as they are the only group examined capable of differentiating N. viridescens and nonmimetic P. cinereus. Additionally, patterns of conspicuousness suggest that selection from predators may drive the evolution of conspicuousness in this system. This study confirms the expectation that the visual abilities of predators may influence the evolution of Batesian mimicry, but the role of conspicuousness may be more complex than previously thought.
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Affiliation(s)
- Andrew C Kraemer
- Department of Ecology, Evolution, and Organismal Biology, 251 Bessey Hall, Iowa State University, Ames, Iowa, 50011.
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28
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Stevens M, Ruxton GD. Linking the evolution and form of warning coloration in nature. Proc Biol Sci 2011; 279:417-26. [PMID: 22113031 DOI: 10.1098/rspb.2011.1932] [Citation(s) in RCA: 173] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many animals are toxic or unpalatable and signal this to predators with warning signals (aposematism). Aposematic appearance has long been a classical system to study predator-prey interactions, communication and signalling, and animal behaviour and learning. The area has received considerable empirical and theoretical investigation. However, most research has centred on understanding the initial evolution of aposematism, despite the fact that these studies often tell us little about the form and diversity of real warning signals in nature. In contrast, less attention has been given to the mechanistic basis of aposematic markings; that is, 'what makes an effective warning signal?', and the efficacy of warning signals has been neglected. Furthermore, unlike other areas of adaptive coloration research (such as camouflage and mate choice), studies of warning coloration have often been slow to address predator vision and psychology. Here, we review the current understanding of warning signal form, with an aim to comprehend the diversity of warning signals in nature. We present hypotheses and suggestions for future work regarding our current understanding of several inter-related questions covering the form of warning signals and their relationship with predator vision, learning, and links to broader issues in evolutionary ecology such as mate choice and speciation.
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Affiliation(s)
- Martin Stevens
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
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29
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Lee TJ, Speed MP, Stephens PA. Honest Signaling and the Uses of Prey Coloration. Am Nat 2011; 178:E1-9. [DOI: 10.1086/660197] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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30
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Abstract
The mechanisms behind the evolution and maintenance of conspicuous visible polymorphisms comprising tens of morphs present a challenge to evolutionary theory. However, for cryptic forms Endler (Evol. Biol., 11, 1978, 319) conjectured that complex backgrounds facilitate polymorphism because in such habitats there are several ways to resemble the resting surface. We use computer simulation to explore the evolution of cryptic morphs on increasingly complex backgrounds under regimes that include selection for crypsis, apostatic predation and dietary wariness. We show that there is a monotonic increase in the number of morphs evolving in a population as the potential number of cryptic morphs increases. The relationship is very weak with selection for crypsis alone, but much stronger with the addition of apostatic selection. In contrast, when dietary wariness is added to the model the plot of number of morphs maintained, as a function of the potential number of cryptic forms available, is minimized at an intermediate number of cryptic forms, i.e. is V-shaped. These counter-intuitive patterns are robust to varying strengths of apostatic selection and different implementations of dietary wariness, and are more pronounced when predator and prey generation lengths are similar.
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Affiliation(s)
- Daniel W Franks
- Department of Biology, York Centre for Complex Systems Analysis, University of York, York YO10 5DD, UK.
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31
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Speed MP, Ruxton GD, Blount JD, Stephens PA. Diversification of honest signals in a predator-prey system. Ecol Lett 2010; 13:744-53. [PMID: 20597158 DOI: 10.1111/j.1461-0248.2010.01469.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many animals use bright colouration to advertise their toxicity to predators. It is now well established that both toxicity and colouration are often variable within prey populations, yet it is an open question whether or not brighter signals should be used by the more toxic members of the population. We therefore describe a model in which signal honesty can easily be explained. We assumed that prey toxicity is environmentally conferred and variable between individuals, and that signalling bears a cost through attracting the attention of predators. A key assumption is that predators know the mean toxicity associated with each signalling level, so that the probability of attack for each signal value declines as mean toxicity associated with that signal increases. The probability of death given attack for each individual, however, declines with the precise value of its own toxicity, and prey must evolve the optimal level of signal to match the toxicity level that they acquire from their environments. At the start of our simulations there is no signalling system, as neither prey nor predators have biases that favour signal diversification. Over evolutionary time, however, a positive correlation emerges between signal strength and the mean toxicity associated with each signal level. When stability is reached, predators change their behaviour so that they now tend to avoid prey that signal conspicuously. In addition to predicting within-species signal reliability, our model can explain the initial evolution of aposematic displays without the need to assume special biases in predators.
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LETTIERI L, STREELMAN JT. Colourful stripes send mixed messages to safe and risky partners in a diffuse cleaning mutualism. J Evol Biol 2010; 23:2289-99. [DOI: 10.1111/j.1420-9101.2010.02098.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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