1
|
Tomizuka H, Tachiki Y. The eco-evolutionary dynamics of Batesian mimicry. J Theor Biol 2024; 577:111683. [PMID: 38008158 DOI: 10.1016/j.jtbi.2023.111683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 11/12/2023] [Accepted: 11/21/2023] [Indexed: 11/28/2023]
Abstract
Batesian mimicry is a strategy in which palatable prey species (mimic-species) resemble unpalatable prey species with aposematism (model-species). Theoretical studies on Batesian mimicry have been conducted in terms of their evolutionary significance and ecological consequences. However, despite the importance of eco-evolutionary feedback, the evolution and population dynamics of mimicry complex have long been explored separately. Previous studies on the dynamics of mimicry complex have proposed the possibility of the extinction of unpalatable species due to high predation by predators confusing palatable and unpalatable species. If the abundance of palatable species was large in comparison with unpalatable species, predation pressure on both unpalatable and palatable species became severe, resulting in the extinction of the unpalatable species. We hypothesized that palatable species evolved not to be similar to unpalatable species when unpalatable species became rare, because this situation is no longer advantageous for palatable species to mimic unpalatable species. Here, we constructed the eco-evolutionary dynamics of unpalatable and palatable species, and demonstrated that the evolutionary process of palatable species, which has been overlooked in previous theoretical studies, could rescue the unpalatable species from extinction. We modeled predators' foraging decisions based on signal detection theory. We assumed that palatable species evolve in a trait space, in which there are separate adaptive peaks on either side of an adaptive valley for mimicry and cryptic phenotypes. Then, we derived the stability conditions of the equilibria. As a result, the evolution of a cryptic phenotype in palatable species was driven when unpalatable species was rare, which mitigated predation pressure on unpalatable species through the reduction in the probability to be attacked. This could work to rescue unpalatable species from extinction.
Collapse
Affiliation(s)
- Haruto Tomizuka
- Department of Biological Sciences, Tokyo Metropolitan University, Tokyo 192-0397, Japan.
| | - Yuuya Tachiki
- Department of Biological Sciences, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| |
Collapse
|
2
|
Michel A, Johnson JR, Szeligowski R, Ritchie EG, Sih A. Integrating sensory ecology and predator-prey theory to understand animal responses to fire. Ecol Lett 2023; 26:1050-1070. [PMID: 37349260 DOI: 10.1111/ele.14231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 01/11/2023] [Accepted: 02/10/2023] [Indexed: 06/24/2023]
Abstract
Fire regimes are changing dramatically worldwide due to climate change, habitat conversion, and the suppression of Indigenous landscape management. Although there has been extensive work on plant responses to fire, including their adaptations to withstand fire and long-term effects of fire on plant communities, less is known about animal responses to fire. Ecologists lack a conceptual framework for understanding behavioural responses to fire, which can hinder wildlife conservation and management. Here, we integrate cue-response sensory ecology and predator-prey theory to predict and explain variation in if, when and how animals react to approaching fire. Inspired by the literature on prey responses to predation risk, this framework considers both fire-naïve and fire-adapted animals and follows three key steps: vigilance, cue detection and response. We draw from theory on vigilance tradeoffs, signal detection, speed-accuracy tradeoffs, fear generalization, neophobia and adaptive dispersal. We discuss how evolutionary history with fire, but also other selective pressures, such as predation risk, should influence animal behavioural responses to fire. We conclude by providing guidance for empiricists and outlining potential conservation applications.
Collapse
Affiliation(s)
- Alice Michel
- Animal Behavior Graduate Group, University of California, Davis, California, USA
| | - Jacob R Johnson
- Animal Behavior Graduate Group, University of California, Davis, California, USA
| | - Richard Szeligowski
- Department of Environmental Science & Policy, University of California, Davis, California, USA
| | - Euan G Ritchie
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Burwood, Victoria, Australia
| | - Andrew Sih
- Department of Environmental Science & Policy, University of California, Davis, California, USA
| |
Collapse
|
3
|
Turner CR, Spike M, Magrath RD. The evolution of eavesdropping on heterospecific alarm calls: Relevance, reliability, and personal information. Ecol Evol 2023; 13:e10272. [PMID: 37449019 PMCID: PMC10337016 DOI: 10.1002/ece3.10272] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/21/2023] [Indexed: 07/18/2023] Open
Abstract
Interceptive eavesdropping on the alarm calls of heterospecifics provides crucial information about predators. Previous research suggests predator discrimination, call relevance, reliability, and reception explain when eavesdropping will evolve. However, there has been no quantitative analysis to scrutinize these principles, or how they interact. We develop a mathematical framework that formalizes the study of the key principles thought to select for eavesdropping. Interceptive eavesdropping appears to be greatly affected by the threat faced by caller and eavesdropper, as well as presence of informational noise affecting the detection of calls and predators. Accordingly, our model uses signal detection theory to examine when selection will favor alarm calling by a sender species and fleeing by an eavesdropping receiver species. We find eavesdropping is most strongly selected when (1) the receiver faces substantial threats, (2) species are ecologically similar, (3) senders often correctly discriminate threats, (4) receivers often correctly perceive calls, and (5) the receiver's personal discrimination of threats is poor. Furthermore, we find (6) that very high predation levels can select against eavesdropping because prey cannot continuously flee and must conserve energy. Reliability of heterospecific calls for identifying threats is thought to be important in selecting for eavesdropping. Consequently, we formally define reliability, showing its connection to specificity and sensitivity, clarifying how these quantities can be measured. We find that high call relevance, due to similar vulnerability to predators between species, strongly favors eavesdropping. This is because senders trade-off false alarms and missed predator detections in a way that is also favorable for the eavesdropper, by producing less of the costlier error. Unexpectedly, highly relevant calls increase the total number of combined errors and so have lower reliability. Expectedly, when noise greatly affects personally gathered cues to threats, but not heterospecific calls or detection of predators, eavesdropping is favored.
Collapse
Affiliation(s)
- Cameron Rouse Turner
- Computational Cognitive Science Lab, Department of Computer SciencePrinceton UniversityPrincetonNew JerseyUSA
- Division of Ecology and Evolution, Research School of BiologyAustralian National UniversityCanberraAustralian Capital TerritoryAustralia
| | - Matt Spike
- Centre for Language Evolution, School of Philosophy, Psychology and Language SciencesThe University of EdinburghEdinburghUK
| | - Robert D. Magrath
- Division of Ecology and Evolution, Research School of BiologyAustralian National UniversityCanberraAustralian Capital TerritoryAustralia
| |
Collapse
|
4
|
Sherratt TN, O'Neill E. Signal detection models as contextual bandits. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230157. [PMID: 37351497 PMCID: PMC10282591 DOI: 10.1098/rsos.230157] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/30/2023] [Indexed: 06/24/2023]
Abstract
Signal detection theory (SDT) has been widely applied to identify the optimal discriminative decisions of receivers under uncertainty. However, the approach assumes that decision-makers immediately adopt the appropriate acceptance threshold, even though the optimal response must often be learned. Here we recast the classical normal-normal (and power-law) signal detection model as a contextual multi-armed bandit (CMAB). Thus, rather than starting with complete information, decision-makers must infer how the magnitude of a continuous cue is related to the probability that a signaller is desirable, while simultaneously seeking to exploit the information they acquire. We explain how various CMAB heuristics resolve the trade-off between better estimating the underlying relationship and exploiting it. Next, we determined how naive human volunteers resolve signal detection problems with a continuous cue. As anticipated, a model of choice (accept/reject) that assumed volunteers immediately adopted the SDT-predicted acceptance threshold did not predict volunteer behaviour well. The Softmax rule for solving CMABs, with choices based on a logistic function of the expected payoffs, best explained the decisions of our volunteers but a simple midpoint algorithm also predicted decisions well under some conditions. CMABs offer principled parametric solutions to solving many classical SDT problems when decision-makers start with incomplete information.
Collapse
Affiliation(s)
- Thomas N. Sherratt
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
| | - Erica O'Neill
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
| |
Collapse
|
5
|
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
| |
Collapse
|
6
|
|
7
|
Downie AE, Mayer A, Metcalf CJE, Graham AL. Optimal immune specificity at the intersection of host life history and parasite epidemiology. PLoS Comput Biol 2021; 17:e1009714. [PMID: 34932551 PMCID: PMC8730424 DOI: 10.1371/journal.pcbi.1009714] [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: 08/27/2021] [Revised: 01/05/2022] [Accepted: 12/02/2021] [Indexed: 11/30/2022] Open
Abstract
Hosts diverge widely in how, and how well, they defend themselves against infection and immunopathology. Why are hosts so heterogeneous? Both epidemiology and life history are commonly hypothesized to influence host immune strategy, but the relationship between immune strategy and each factor has commonly been investigated in isolation. Here, we show that interactions between life history and epidemiology are crucial for determining optimal immune specificity and sensitivity. We propose a demographically-structured population dynamics model, in which we explore sensitivity and specificity of immune responses when epidemiological risks vary with age. We find that variation in life history traits associated with both reproduction and longevity alters optimal immune strategies-but the magnitude and sometimes even direction of these effects depends on how epidemiological risks vary across life. An especially compelling example that explains previously-puzzling empirical observations is that depending on whether infection risk declines or rises at reproductive maturity, later reproductive maturity can select for either greater or lower immune specificity, potentially illustrating why studies of lifespan and immune variation across taxa have been inconclusive. Thus, the sign of selection on the life history-immune specificity relationship can be reversed in different epidemiological contexts. Drawing on published life history data from a variety of chordate taxa, we generate testable predictions for this facet of the optimal immune strategy. Our results shed light on the causes of the heterogeneity found in immune defenses both within and among species and the ultimate variability of the relationship between life history and immune specificity.
Collapse
Affiliation(s)
- Alexander E. Downie
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Andreas Mayer
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - C. Jessica E. Metcalf
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
- School of Public and International Affairs, Princeton University, Princeton, New Jersey, United States of America
| | - Andrea L. Graham
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|