scholarly journals Maintaining mimicry diversity: optimal warning colour patterns differ among microhabitats in Amazonian clearwing butterflies

2017 ◽  
Vol 284 (1855) ◽  
pp. 20170744 ◽  
Author(s):  
Keith R. Willmott ◽  
Julia C. Robinson Willmott ◽  
Marianne Elias ◽  
Chris D. Jiggins
Keyword(s):  
Bird Species ◽  
Warning Signal ◽  
Colour Pattern ◽  
Butterfly Species ◽  
Insectivorous Birds ◽  
Selection For ◽  
Colour Patterns ◽  
Measured Distribution ◽  
Predator Defence

Mimicry is one of the best-studied examples of adaptation, and recent studies have provided new insights into the role of mimicry in speciation and diversification. Classical Müllerian mimicry theory predicts convergence in warning signal among protected species, yet tropical butterflies are exuberantly diverse in warning colour patterns, even within communities. We tested the hypothesis that microhabitat partitioning in aposematic butterflies and insectivorous birds can lead to selection for different colour patterns in different microhabitats and thus help maintain mimicry diversity. We measured distribution across flight height and topography for 64 species of clearwing butterflies (Ithomiini) and their co-mimics, and 127 species of insectivorous birds, in an Amazon rainforest community. For the majority of bird species, estimated encounter rates were non-random for the two most abundant mimicry rings. Furthermore, most butterfly species in these two mimicry rings displayed the warning colour pattern predicted to be optimal for anti-predator defence in their preferred microhabitats. These conclusions were supported by a field trial using butterfly specimens, which showed significantly different predation rates on colour patterns in two microhabitats. We therefore provide the first direct evidence to support the hypothesis that different mimicry patterns can represent stable, community-level adaptations to differing biotic environments.

scholarly journals Dog colour patterns explained by modular promoters of ancient canid origin

2021 ◽  
Author(s):  
Danika L. Bannasch ◽  
Christopher B. Kaelin ◽  
Anna Letko ◽  
Robert Loechel ◽  
Petra Hug ◽  
...  
Keyword(s):  
Colour Pattern ◽  
Hair Cycle ◽  
Temporal And Spatial Distribution ◽  
Multiple Alleles ◽  
Haplotype Combination ◽  
Regulatory Modules ◽  
Regulatory Module ◽  
Temporal And Spatial ◽  
Selection For ◽  
Colour Patterns

AbstractDistinctive colour patterns in dogs are an integral component of canine diversity. Colour pattern differences are thought to have arisen from mutation and artificial selection during and after domestication from wolves but important gaps remain in understanding how these patterns evolved and are genetically controlled. In other mammals, variation at the ASIP gene controls both the temporal and spatial distribution of yellow and black pigments. Here, we identify independent regulatory modules for ventral and hair cycle ASIP expression, and we characterize their action and evolutionary origin. Structural variants define multiple alleles for each regulatory module and are combined in different ways to explain five distinctive dog colour patterns. Phylogenetic analysis reveals that the haplotype combination for one of these patterns is shared with Arctic white wolves and that its hair cycle-specific module probably originated from an extinct canid that diverged from grey wolves more than 2 million years ago. Natural selection for a lighter coat during the Pleistocene provided the genetic framework for widespread colour variation in dogs and wolves.

scholarly journals Evolution of the wave: aerodynamic and aposematic functions of butterfly wing motion

2007 ◽  
Vol 274 (1612) ◽  
pp. 913-917 ◽  
Author(s):  
Robert B Srygley
Keyword(s):  
Beat Frequency ◽  
Warning Signal ◽  
Colour Pattern ◽  
Butterfly Species ◽  
Wing Beat ◽  
Butterfly Wing ◽  
Motion Cues ◽  
Wing Beat Frequency ◽  
Wing Motion ◽  
Heliconius Cydno

Many unpalatable butterfly species use coloration to signal their distastefulness to birds, but motion cues may also be crucial to ward off predatory attacks. In previous research, captive passion-vine butterflies Heliconius mimetic in colour pattern were also mimetic in motion. Here, I investigate whether wing motion changes with the flight demands of different behaviours. If birds select for wing motion as a warning signal, aposematic butterflies should maintain wing motion independently of behavioural context. Members of one mimicry group ( Heliconius cydno and Heliconius sapho ) beat their wings more slowly and their wing strokes were more asymmetric than their sister-species ( Heliconius melpomene and Heliconius erato , respectively), which were members of another mimicry group having a quick and steady wing motion. Within mimicry groups, wing beat frequency declined as its role in generating lift also declined in different behavioural contexts. In contrast, asymmetry of the stroke was not associated with wing beat frequency or behavioural context—strong indication that birds process and store the Fourier motion energy of butterfly wings. Although direct evidence that birds respond to subtle differences in butterfly wing motion is lacking, birds appear to generalize a motion pattern as much as they encounter members of a mimicry group in different behavioural contexts.

scholarly journals Stabilizing selection on individual pattern elements of aposematic signals

2017 ◽  
Vol 284 (1861) ◽  
pp. 20170926 ◽  
Author(s):  
Anne E. Winters ◽  
Naomi F. Green ◽  
Nerida G. Wilson ◽  
Martin J. How ◽  
Mary J. Garson ◽  
...  
Keyword(s):  
Pattern Analysis ◽  
Marine Organism ◽  
Warning Signal ◽  
Colour Pattern ◽  
Stabilizing Selection ◽  
Warning Signals ◽  
Fish Predator ◽  
Selection For ◽  
Aposematic Signals ◽  
Behavioural Experiments

Warning signal variation is ubiquitous but paradoxical: low variability should aid recognition and learning by predators. However, spatial variability in the direction and strength of selection for individual elements of the warning signal may allow phenotypic variation for some components, but not others. Variation in selection may occur if predators only learn particular colour pattern components rather than the entire signal. Here, we used a nudibranch mollusc, Goniobranchus splendidus , which exhibits a conspicuous red spot/white body/yellow rim colour pattern, to test this hypothesis. We first demonstrated that secondary metabolites stored within the nudibranch were unpalatable to a marine organism. Using pattern analysis, we demonstrated that the yellow rim remained invariable within and between populations; however, red spots varied significantly in both colour and pattern. In behavioural experiments, a potential fish predator, Rhinecanthus aculeatus , used the presence of the yellow rims to recognize and avoid warning signals. Yellow rims remained stable in the presence of high genetic divergence among populations. We therefore suggest that how predators learn warning signals may cause stabilizing selection on individual colour pattern elements, and will thus have important implications on the evolution of warning signals.

scholarly journals Heritable variation in colour patterns mediating individual recognition

2017 ◽  
Vol 4 (2) ◽  
pp. 161008 ◽  
Author(s):  
Michael J. Sheehan ◽  
Juanita Choo ◽  
Elizabeth A. Tibbetts
Keyword(s):  
Genetic Diversity ◽  
Balancing Selection ◽  
Phenotypic Diversity ◽  
Individual Recognition ◽  
Genetic Correlations ◽  
Colour Pattern ◽  
Heritable Variation ◽  
Pattern Diversity ◽  
Selection For ◽  
Colour Patterns

Understanding the developmental and evolutionary processes that generate and maintain variation in natural populations remains a major challenge for modern biology. Populations of Polistes fuscatus paper wasps have highly variable colour patterns that mediate individual recognition. Previous experimental and comparative studies have provided evidence that colour pattern diversity is the result of selection for individuals to advertise their identity. Distinctive identity-signalling phenotypes facilitate recognition, which reduces aggression between familiar individuals in P. fuscatus wasps. Selection for identity signals may increase phenotypic diversity via two distinct modes of selection that have different effects on genetic diversity. Directional selection for increased plasticity would greatly increase phenotypic diversity but decrease genetic diversity at associated loci. Alternatively, heritable identity signals under balancing selection would maintain genetic diversity at associated loci. Here, we assess whether there is heritable variation underlying colour pattern diversity used for facial recognition in a wild population of P. fuscatus wasps. We find that colour patterns are heritable and not Mendelian, suggesting that multiple loci are involved. Additionally, patterns of genetic correlations among traits indicated that many of the loci underlying colour pattern variation are unlinked and independently segregating. Our results support a model where the benefits of being recognizable maintain genetic variation at multiple unlinked loci that code for phenotypic diversity used for recognition.

scholarly journals Evolution of the potassium channel gene Kcnj13 underlies colour pattern diversification in Danio fish

2020 ◽  
Author(s):  
Marco Podobnik ◽  
Hans Georg Frohnhöfer ◽  
Christopher M. Dooley ◽  
Anastasia Eskova ◽  
Christiane Nüsslein-Volhard ◽  
...  
Keyword(s):  
Potassium Channel ◽  
Evolutionary Biology ◽  
Morphological Evolution ◽  
Colour Pattern ◽  
Minor Role ◽  
Cell Contact ◽  
Leading Role ◽  
Vertical Bars ◽  
Colour Patterns

AbstractThe genetic basis of morphological variation provides a major topic in evolutionary biology1-6. Colour patterns in fish are among the most diverse of all vertebrates. Species of the genus Danio display strikingly different colour patterns ranging from horizontal stripes, to vertical bars or spots7-10. Stripe formation in zebrafish, Danio rerio, oriented by the horizontal myoseptum, is a self-organizing process based on cell-contact-mediated interactions between three types of chromatophores with a leading role of iridophores11-14. We investigated genes known to regulate chromatophore interactions in zebrafish as candidates that might have evolved to produce a pattern of vertical bars in its sibling species, Danio aesculapii8,10. Using gene editing15-17 we generated several mutants in D. aesculapii that demonstrate a lower complexity in the interactions between chromatophores in this species, as well as a minor role of iridophores in patterning. Complementation tests in interspecific hybrids18,19 identified obelix/Kcnj13, which encodes an inwardly rectifying potassium channel (Kir7.1)20, as a gene evolved between D. rerio and D. aesculapii as well as in two of seven more Danio species tested. Our results demonstrate that the CRISPR/Cas9-system allows straightforward genetic tests also in non-model vertebrates to identify genes that underlie morphological evolution.

scholarly journals Locomotor mimicry in Heliconius butterflies: contrast analyses of flight morphology and kinematics

1999 ◽  
Vol 354 (1380) ◽  
pp. 203-214 ◽  
Author(s):  
Robert B. Srygley
Keyword(s):  
Wing Length ◽  
Beat Frequency ◽  
Warning Signal ◽  
Wing Shape ◽  
The Body ◽  
Colour Pattern ◽  
Müllerian Mimicry ◽  
Flight Morphology ◽  
Mullerian Mimicry ◽  
Colour Patterns

Müllerian mimicry is a mutualism involving the evolutionary convergence of colour patterns of prey on a warning signal to predators. Behavioural mimicry presumably adds complexity to the signal and makes it more difficult for Batesian mimics to parasitize it. To date, no one has quantified behavioural mimicry in Müllerian mimicry groups. However, morphological similarities among members of mimicry groups suggested that pitching oscillations of the body and wing–beat frequency (WBF) might converge with colour pattern. I compared the morphology and kinematics of four Heliconius species, which comprised two mimicry pairs. Because the mimics arose from two distinct lineages, the relative contributions of mimicry and phylogeny to variation in the species' morphologies and kinematics were examined. The positions of the centre of body mass and centre of wing mass and wing shape diverged among species within lineages, and converged among species within mimicry groups. WBF converged within mimicry groups, and it was coupled with body pitching frequency. However, body–pitching frequency was too variable to distinguish mimicry groups. Convergence in WBF may be due, at least in part, to biomechanical consequences of similarities in wing length, wing shape or the centre of wing mass among co–mimics. Nevertheless, convergence in WBF among passion–vine butterflies serves as the first evidence of behavioural mimicry in a mutualistic context.

scholarly journals Paradox lost: variable colour-pattern geometry is associated with differences in movement in aposematic frogs

2014 ◽  
Vol 10 (6) ◽  
pp. 20140193 ◽  
Author(s):  
Bibiana Rojas ◽  
Jennifer Devillechabrolle ◽  
John A. Endler
Keyword(s):  
Morphological Traits ◽  
Movement Patterns ◽  
Colour Pattern ◽  
Warning Signals ◽  
Signal Variation ◽  
Random Movement ◽  
Tracking Ability ◽  
Colour Patterns ◽  
Predator Defence

Aposematic signal variation is a paradox: predators are better at learning and retaining the association between conspicuousness and unprofitability when signal variation is low. Movement patterns and variable colour patterns are linked in non-aposematic species: striped patterns generate illusions of altered speed and direction when moving linearly, affecting predators' tracking ability; blotched patterns benefit instead from unpredictable pauses and random movement. We tested whether the extensive colour-pattern variation in an aposematic frog is linked to movement, and found that individuals moving directionally and faster have more elongated patterns than individuals moving randomly and slowly. This may help explain the paradox of polymorphic aposematism: variable warning signals may reduce protection, but predator defence might still be effective if specific behaviours are tuned to specific signals. The interacting effects of behavioural and morphological traits may be a key to the evolution of warning signals.

The genetics of warning colour in Peruvian hybrid zones of Heliconius erato and H. melpomene

1989 ◽  
Vol 236 (1283) ◽  
pp. 163-185 ◽  
Keyword(s):  
Genetic Control ◽  
Genetic System ◽  
Colour Pattern ◽  
Stabilizing Selection ◽  
Hybrid Zones ◽  
Warning Signals ◽  
Gradual Evolution ◽  
Selection For ◽  
Colour Patterns ◽  
Ray Patterns

Heliconius warning colour is a good example of a genetic system shaped by strong selection. The genetics of colour patterns in interracial hybrid zones within both H. erato and H. melpomene was investigated. Within each species, the loci controlling these pattern differences are mostly homologous to those known from other races, but have somewhat different phenotypic effects. The precise genetic control varies geographically, even for nearly identical colour patterns. Independent evolution of the same pattern is unlikely; instead evolution of the genetic system is hypothesized to have occurred while stabilizing selection preserved the pattern itself. Single genes often control more than one pattern element. This apparent pleiotropy is in part due to tightly linked loci within 'supergenes': rare recombinants (possibly mutants) in genes controlling 'dennis' and 'ray' patterns were found in both species. However, supergenes, which are likely in polymorphic Batesian mimicry, are not expected to accumulate in Müllerian mimics because polymorphisms, which would favour their evolution, are too transient. The existence of supergenes in Heliconius suggests that major switch genes are gradually built up within a locus rather than evolving wholly by macromutation or by selection for tighter linkage of mimetic genes. This gradual evolution at a single locus might be necessitated by a lack of other sites that can control warning patterns. These genes are strongly epistatic, and heterozygotes and hybrid homozygotes have 'fuzzier' (less sharply defined) and more variable patterns than the pure races. The genetic system controlling colour pattern in Heliconius is clearly canalized and coadapted to produce efficient warning signals.

scholarly journals Hard to catch: Experimental evidence supports evasive mimicry

2020 ◽  
Author(s):  
Erika Páez V ◽  
Janne K. Valkonen ◽  
Keith R. Willmott ◽  
Pável Matos-Maraví ◽  
Marianne Elias ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Empirical Evidence ◽  
Avoidance Learning ◽  
Colour Pattern ◽  
Alternative Scenario ◽  
Wing Patterns ◽  
Selection For ◽  
Colour Patterns ◽  
Blue Tits ◽  
Candidate Group

ABSTRACTMost research on aposematism has focused on chemically defended prey, but signalling difficulty of capture remains poorly explored. Similarly to classical Batesian and Müllerian mimicry related to distastefulness, such “evasive aposematism” may also lead to convergence in warning colours, known as evasive mimicry. A prime candidate group for evasive mimicry are Adelpha butterflies, which are agile insects and show remarkable colour pattern convergence. We tested the ability of naïve blue tits to learn to avoid and generalise Adelpha wing patterns associated with difficulty of capture, and compared their response to that of birds that learned to associate the same wing patterns with distastefulness. Birds learned to avoid all wing patterns tested, but learning was faster with evasive prey compared with distasteful prey. Birds generalised their learned avoidance from evasive models to imperfect mimics if the mimic shared colours with the model. Despite imperfect mimics gaining protection from bird’s generalisation, perfect mimics always had the best fitness, supporting selection for accurate mimicry. Faster avoidance learning and broader generalisation of evasive prey suggest that being hard to catch may deter predators at least as effectively as distastefulness. Our results provide empirical evidence for a potentially widespread alternative scenario, evasive mimicry, for the evolution of similar aposematic colour patterns.

scholarly journals Two-headed butterfly vs. mantis: do false antennae matter?

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3493 ◽  
Author(s):  
Tania G. López-Palafox ◽  
Carlos R. Cordero
Keyword(s):  
Experimental Evidence ◽  
Butterfly Species ◽  
Colour Patterns

The colour patterns and morphological peculiarities of the hindwings of several butterfly species result in the appearance of a head at the rear end of the insect’s body. Although some experimental evidence supports the hypothesis that the “false head” deflects predator attacks towards the rear end of the butterfly, more research is needed to determine the role of the different components of the “false head”. We explored the role of hindwing tails (presumably mimicking antennae) in predator deception in the “false head” butterfly Callophrys xami. We exposed butterflies with intact wings and with hindwing tails experimentally ablated to female mantises (Stagmomantis limbata). We found no differences in the number of butterflies being attacked and the number of butterflies escaping predation between both groups. However, our behavioural observations indicate that other aspects of the “false head” help C. xami survive some mantis attacks, supporting the notion that they are adaptations against predators.

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