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In evolutionary ecology, 'mimicry' describes a situation where one organism, the 'mimic', has evolved to share common outward characteristics with another organism, the 'model', through the selective action of a 'signal-receiver' or "'dupe'". Collectively this known as a 'mimicry complex'. The model is usually another species, or less commonly, the mimic's own species, including automimicry, where one part of the body bears superficial similarity to another. The signal-receiver is typically another intermediate organism, e.g the common predator of two species, but may actually be the model itself (such as an orchid resembling a female wasp). As an interaction, mimicry is in most cases advantageous to the mimic and harmful to the receiver, but may increase, reduce or have no effect on the fitness of the model depending on the situation. Models themselves are difficult to define in some cases, for example eye spots may not bear resemblance to any specific organism's eyes, and camouflage often cannot be attributed to any particular model.
Camouflage, in which a species appears similar to its surroundings, is essentially a form of visual mimicry, but usually is restricted to cases where the model is not another organism. The lack of a true distinction between the two phenomena can be seen in animals that resemble twigs, bark, leaves or flowers, in that they are often classified as camouflaged (a plant constitutes its "surroundings"), but are sometimes classified as mimics (a plant is also an organism). Crypsis is a broader concept that encompasses all forms of detection evasion, such as mimicry, camouflage, hiding etc.
Though mimicry is most obvious to humans in visual mimics, others senses such as olfaction (smell) or hearing may be involved, and more than one type of signal may be employed.^[1] Mimicry may involve morphology, behavior, and other properties. In any case, the signal always functions to deceive the receiver by providing misleading information. In evolutionary biology terms, this phenomenon is a form of co-evolution usually involving an evolutionary arms race, and should not be confused with convergent evolution, which occurs when species come to resemble on another ''independently'' due to similar lifestyles.
Mimics may have multiple models during different stages of their life cycle, or they may be polymorphic, with different individuals imitating different models. Models themselves may have more than one mimic, though frequency dependent selection favors mimicry where models outnumber mimics. Models tend to be relatively closely related organisms,^[2] but mimicry of vastly different species is also known. Most known mimics are insects¹, though many other animal mimics including mammals are known. Plants themselves may also be mimics, though less research has been carried out on this subject.^[3] Fungi may also be involved both as models,^[4] in the induction of mimicry,^[5][6] or as mimics themselves.Wickler, Wolfgang (1998). “Mimicry”. ''Encyclopædia Britannica'', 15th edition. Macropædia 24, 144–151. http://www.britannica.com/eb/article-11910

Contents

Classification

Defensive

Batesian

Vavilovian

Müllerian

Mertensian

Aggressive

Automimicry

Bakerian

Other

Mimicry and convergent evolution

See also

Similar terms

Further reading

References

External links

Classification

Many types of mimicry have been described. An overview of each follows, highlighting the similarities and differences between the various forms. Some cases may belong to more than one class, for example there are forms of automimicry that are also aggressive.

Defensive

Batesian

'Batesian mimicry' is named after Henry Walter Bates, an English naturalist whose work on butterflies in the Amazon rainforest (including ''The Naturalist on the River Amazons'') was pioneering in this field of study.^[7][8] In this type of mimicry the mimic sends signals similar to the model, but does not share the attribute that makes it unprofitable to predators (e.g. unpalatability).
Examples:

★ Lepidoptera

★
★ The Ash Borer (''Podosesia syringae''), a moth of the Clearwing family (Sesiidae), is a Batesian mimic of the Common wasp because it resembles the wasp, but is not capable of stinging. A predator that has learned to avoid the wasp would similarly avoid the Ash Borer.

★
★ Plain Tiger (''Danaus chrysippus'') - an unpalatable model with a number of mimics.

★
★ Common Crow (''Euploea core'') - an unpalatable model with a number of mimics. See also under ''Müllerian mimicry'' below.

★
★ ''Consul fabius'' and ''Eresia eunice'' imitate unpalatable ''Heliconius'' butterflies such as ''H. ismenius''.¹⁴

★
★ Several palatable butterflies resemble different species from the highly noxious papilionine genus ''Battus''.¹⁴

★
★ Several palatable moths produce ultrasonic click calls to mimic the unpalatable tiger moths.Barber, J. R. and W. E. Conner. (2007) Acoustic mimicry in a predator–prey interaction. Proc. Nat. Acad. Sci. 104(22):9331-9334
[2]

★ The False Cobra (''Malpolon moilensis'') is a mildly venomous but harmless colubrid snake which mimics the characteristic "hood" of an Indian cobra's threat display. The Eastern Hognose Snake (''Heterodon platirhinos'') similarly mimics the threat display of poisonous snakes.

★ Octopuses of the genus ''Thaumoctopus'' (the Mimic Octopus and the "wunderpus") are able to intentionally alter their body shape and color so that they resemble dangerous sea snakes or lionfish.[3]

Vavilovian

'Vavilovian mimicry' or 'weed mimicry' is named after Nikolai Ivanovich Vavilov, a prominent Russian botanist and geneticist who identified the centres of origin of cultivated plants.^[9] In this form of mimicry, the mimic comes to resemble a domesticated plant through generations of artificial selection, and may eventually be domesticated itself. This type of mimicry does not occur in ecosystems unaltered by humans.
Examples:

★ ''Echinochloa oryzoides'' is a species of grass which is found as a weed in rice (''Oryza sativa'') fields. The plant looks similar to rice and its seeds are often mixed in rice and difficult to separate. This close similarity was enhanced by the weeding process which is a selective force that increases the similarity of the weed in each subsequent generation.

Müllerian

'Müllerian mimicry' describes a situation where two or more species have very similar warning or aposematic signals and both share genuine anti-predation attributes (e.g. being unpalatable). At first Bates could not explain why this should be so; if both were harmful why did one need to mimic another? The German naturalist Fritz Müller put forward the first explanation for this phenomenon: If two species were confused with one another by a common predator, individuals in both would be more likely to survive.^[11] This type of mimicry is unique in several respects. Firstly, both the mimic and the model benefit from the interaction, which could thus be classified as mutualism in this respect. The signal receiver is also advantaged by this system, despite being deceived regarding species identity, as it avoids potentially harmful encounters. The usually clear identity of mimic and model are also blurred. In cases where one species is scarce and another abundant, the rare species can be said to be the mimic. When both are present in similar numbers however it is more realistic to speak of each as ''comimics'' than of a distinct 'mimic' and 'model' species, as their warning signals tend to converge toward something intermediate between the two.^[12]
Examples:

★ Lepidoptera

★
★ The Monarch Butterfly (''Danaus plexippus'') is a member of a Müllerian complex with the Viceroy butterfly (''Limenitis archippus'') in shared coloration patterns and display behavior. The Viceroy has subspecies with somewhat different coloration, each one very closely matching the local ''Danaus'' species. E.g., in Florida, the pairing is of the Viceroy and the Queen Butterfly, and in Mexico, the Viceroy resembles the Soldier Butterfly. Therefore, the Viceroy is a single species involved in three different Müllerian pairs.Ritland, D.B. 1995. Comparative unpalatability of mimetic viceroy butterflies (''Limenitis archippus'') from four south-eastern United States populations. ''Oecologia'' 103: 327-336 This example was long believed to be a case of Batesian mimicry, with the Viceroy being the mimic and the Monarch the model, but it was more recently determined that the Viceroy is actually the ''more'' unpalatable species, though there is considerable individual variation.^[13] While ''L. archippus'' is really bad-tasting, ''Danaus'' species tend to be toxic rather than just repugnant, due to their different food plants.

★
★ Unpalatable ''Euploea'' species look very similar. See also under ''Batesian mimicry'' above.

★
★ The genus ''Morpho'' is palatable but are very strong fliers; birds - even species which are specialized for catching butterflies on the wing - find it very hard to catch them. The conspicuous blue coloration shared by most ''Morpho'' species seems to be a case of Müllerian mimicry.¹⁴

★
★ The "orange complex" of species, including the heliconiines ''Agraulis vanillae'', ''Dryadula phaetusa'', and ''Dryas iulia'' which all taste bad.^[14]

★
★ Many different tiger moths make ultrasonic clicking calls to warn bats that they are unpalatable. Presumably a bat may learn to avoid ''any'' signalling moths, which would make this an example of Müllerian mimicry.

★ Various bees and numerous vespid and sphecoid wasps: These animals are examples of Müllerian mimics because they have the aposematic yellow and black stripes (sometimes black and red, or black and white). All are potentially harmful to predators, fulfilling the second requirement of Müllerian mimicry.

Mertensian

Texas Coral Snake, ''Micrurus tener''

'Mertensian mimicry' is named after the late German herpetologist Robert Mertens,^[15] and is often considered a subtype of Müllerian mimicry. In this case both harmless and deadly mimics resemble a dangerous but not usually deadly species (if the predator dies, it cannot learn to recognize a trait, e.g. a warning coloration).
Examples:

★ Some Milk Snake (''Lampropeltis triangulum'') subspecies (harmless), the moderately toxic False Coral Snakes (genus ''Erythrolamprus''), and the deadly Coral Snakes all have a red background color with black and white/yellow stripes. In this system, both the milk snakes and the deadly coral snakes are mimics, whereas the false coral snakes are the model.

Aggressive

The Alligator Snapping Turtle uses its tongue to lure fish.

'Aggressive mimicry' (less often known as 'Peckhamian mimicry' after Elizabeth Maria Gifford Peckham) describes predators and parasites which share the same characteristics as a harmless species, allowing them to avoid detection by their prey or host. The mimic may resemble the prey or host itself, or another organism which is either neutral or beneficial to the signal receiver. In this class of mimicry the model may be affected negatively, positively or not at all. Just as parasites can be treated as a form of predator,Begon, M., Townsend, C., Harper, J. (1996) ''Ecology'' (Third edition) Blackwell Science, London 'host-parasite mimicry' is treated here as a subclass of aggressive mimicry.
The mimic may have a particular significance for duped prey. One such case is where the signal receiver is lured toward the mimic, for instance it may resemble the signal receiver's own prey. The Alligator Snapping Turtle (''Macrochelys temminckii'') is a well-camouflaged ambush predator. Its tongue bears a conspicuous pink extension that resembles a worm and can be wriggled around;^[16] fish that try to eat the "worm" are themselves eaten by the turtle. Another case is where males are lured towards what would seem to be a sexually receptive female; the model in this situation being the same species as the dupe. Beginning in the 1960s, James E. Lloyd's investigation of female fireflies of the genus ''Photuris'' revealed they emit the same light signals that females of the genus ''Photinus'' use as a mating signal.^[17] Further research showed male fireflies from several different genera are attracted to these mimics, and are subsequently captured and eaten. Female signals are based on that received from the male, each female having a repertoire of signals matching the delay and duration of the female of the corresponding species. This mimicry may have evolved from non-mating signals that have become modified for predation.^[18]
Luring is not a necessary condition however, as the predator will still have a significant advantage by simply not being identified as such. They may resemble a mutualistic symbiont or a species of little relevance to the prey. A case of the latter situation is the Zone-tailed Hawk, which resembles the Turkey Vulture. It flies amongst them, suddenly breaking from the formation and ambushing its prey.^[19] Here the hawk's presence is of no evident significance to the vultures, affecting them neither negatively or positively.

Two Bluestreak cleaner wrasse cleaning a Potato grouper, ''Epinephelus tukula''

Another interesting example that does not involve any luring is a species of cleaner fish and its mimic, though in this example the model is greatly disadvantaged by the presence of the mimic. Cleaner fish are the allies of many other species, which allow them to eat their parasites and dead skin. Some allow the cleaner to venture inside their body to hunt these parasites. However, one species of cleaner, the Bluestreak cleaner wrasse (''Labroides dimidiatus''), is the unknowing model of a mimetic species, the Sabre-toothed blenny (''Aspidontus taeniatus''). This wrasse, shown to the left cleaning a grouper of the genus ''Epinephelus'', resides in coral reefs in the Indian and the Pacific Oceans, and is recognized by other fishes who then allow it to clean them. Its imposter, a species of blenny, lives in the Indian Ocean and not only looks like it in terms of size and coloration, but even mimics the cleaner's 'dance'. Having fooled its prey into letting its guard down, it then bites it, tearing off a piece of its fin before fleeing the scene. Fish grazed upon in this fashion soon learn to distinguish mimic from model, but because the similarity is close between the two they become much more cautious of the model as well, such that both are affected. Due to victim's ability to discriminate between foe and helper, the blennies have evolved close similarity, right down to the regional level.
Host-parasite mimicry is a situation where a parasite mimics its own host. Cuckoos are a canonical example of brood parasitism, a form of kleptoparasitism where the mother has its offspring raised by another unwitting organism, cutting down its own parental investment in the process. There is also the case of ''interspecific'' brood parasitism where a female lays in another's nest, as illustrated by the Goldeneye (''Bucephala clangula''), a species of duck.^[20] These do not represent a case of mimicry though, as offspring naturally look like those of other females.

Automimicry

'Automimicry' involves the mimic having some part of its body resembling some other part. Examples include snakes in which the tail resembles the head and show behavior such as moving backwards to confuse predators and insects and fishes with eyespots on their hind ends to resemble the head. The term is also used when the mimic imitates other morphs within the same species such as some males looking like females or ''vice versa''.
Examples:

★ Many insects have filamentous "tails" at the ends of their wings which are combined with patterns of markings on the wings themselves to create a "false head" which misdirects predators (e.g., hairstreak butterflies).

★ Several pygmy owls bear "false eyes" on the back of their head to fool predators into believing the owl is alert to their presence.

★ The yellow throated males of the Common Side-blotched Lizard use a 'sneaking' strategy in mating. They look and behave like unreceptive females. This strategy is effective against 'usurper' males with orange throats, but ineffective against blue throated 'guarder' males, which will chase them away. ^[21]

★ Female hyenas have pseudo-penises which make them look like males.^[22]

Bakerian

''Lobelia cardinalis'' is believed to be a Bakerian mimic, attracting humming birds without producing nectar.^[23]

'Bakerian mimicry', named after Herbert G. Baker, occurs where the mimic resembles members of its own or other species, luring pollinators or reaping other benefits, although the mimicry may not be readily apparent due to the fact that the members of the same species may still exhibit sexual dimorphism.
Examples:

★ Common in many species of Caricaceae. Their flowers have little or no nectar but resemble nectar-producing flowers. Pollinators will be fooled into visiting them and thus fertilization is ensured without having to produce a reward for the pollinator.

Other

Some hawk-cuckoos resemble sparrow-hawks.

★ Owl butterflies (genus ''Caligo'') bear eye-spots on the underside of their wings; if turned upside-down, their undersides resemble [4] the face of an owl (such as the Short-eared Owl or the Tropical Screech Owl) for which in turn the butterfly predators - small lizards and birds - would be food. Thus it has been supposed that the eye-spots are a form of Batesian mimicry. However, the pose in which the butterfly resembles an owl's head is not normally adopted in life. While the eye-spots indeed seem to have an anti-predation function, their actual role remains elusive; they are most probably some sort of automimicry.

Mimicry and convergent evolution

It was sometimes assumed that mimicry evolves as a positive adaptation; that is, the mimic gains fitness ''via'' convergent evolution which results in resemblance to another species. However, there are others who suggest that evolution is non-adaptive or merely a result of structural similarities, e.g., the lepidopterist (and sometime author) Vladimir Nabokov argued that much of insect mimicry, including the Viceroy/Monarch mimicry, resulted from the fact that coloration patterns in both species simply had a common structural basis, and thus the tendency for convergence by chance was high.^[24] However, this very example provides evidence precisely to the contrary, as the viceroy's color pattern is completely unlike any of the species to which it is closely related, and the viceroy itself has three color forms, each adapted to resemble a different species of ''Danaus''. Likewise, this example is based on two organisms that are indeed fairly similar in structure (both butterflies), while a great many cases of mimicry (especially in large Batesian/Mũllerian complexes) involve insects from multiple orders that share virtually no structural similarities whatsoever (e.g., beetles, true bugs, moths, wasps, bees, and flies may all belong to a single mimetic complex, despite profound differences¹).

See also

★ Ant mimicry

★ Biomimicry

★ Code-breaking

★ Molecular mimicry

Similar terms

★ 'Mimetic' is an adjective used to describe cases of mimicry, but is also used in mathematics (see mimetic). This should not be confused with memetics, the scientific study of memes.

★ Mimesis refers to imitation, especially relating to the arts.

Further reading

★ Cott, H.B. (1940) ''Adaptive Coloration in Animals''. Methuen and Co, Ltd., London ISBN 0416300502

★ Wickler, W. (1968) ''Mimicry in Plants and Animals'' (Translated from the German) McGraw-Hill, New York. ISBN 0070701008

★ Owen, D. (1980) ''Camouflage and Mimicry''. Oxford University Press ISBN 0192176838

★ Pasteur, Georges (1982). “A classificatory review of mimicry systems”. ''Annual Review of Ecology and Systematics'' '13': 169–199.

★ Brower, L. (ed.) (1988). ''Mimicry and the Evolutionary Process''. Chicago: The University of Chicago Press. ISBN 0226076083

★ An introductory book for a younger audience: Hoff, M. K. (2003) ''Mimicry and Camouflage''. Creative Education. Mankato, Minn. Great Britain. ISBN 1583412379

References

1. Wickler, W. 1968. Mimicry in plants and animals. McGraw-Hill, New York
2. Campbell, N. A. (1996) Biology (4th edition), Chapter 50. Benjamin Cummings, New York ISBN 0-8053-1957-3
3. Boyden, T. C. (1980) Floral Mimicry by Epidendrum ibaguense (Orchidaceae) in Panama ''Evolution'' '34':135-136.
4. Wallace, A. R. (1889) [1] p.207-208. London.
5. Batra L. R.; Batra, S. (1985) Floral Mimicry Induced by Mummy-Berry Fungus Exploits Host's Pollinators as Vectors ''Science'' '228':1011-1013.
6. Roy, B. A. (1994) The Effects of Pathogen-Induced Pseudoflowers and Buttercups on Each Other's Insect Visitation ''Ecology'' '75':352-358.
7. Bates H. W. 1863. ''The naturalist on the river Amazons''. Murray, London.
8. Bates, H. W. (1961) Contributions to an insect fauna of the Amazon valley. Lepidoptera: Heliconidae. ''Transactions of the Linnean Society''. '23':495-566.
9. Vavilov, N. I. (1951) The origin, variation, immunity and breeding of cultivated plants. (Translation by K. S. Chester) ''Chronica Botanica'' 13:1-366.
10. Meyer A (2006) Repeating Patterns of Mimicry. PLoS Biol 4(10): e341 doi:10.1371/journal.pbio.0040341
11. Müller, F. (1879) ''Ituna'' and ''Thyridia''; a remarkable case of mimicry in butterflies. (R. Meldola translation) ''Proclamations of the Entomological Society of London'' 1879:20-29.
12. Flannery, T. F. (2007) "Community ecology: Mimicry complexes". ''Encyclopædia Britannica Online''. http://www.britannica.com/eb/article-9117280/community-ecology
13. Ritland, D.B., & Brower, L.P. 1991. The viceroy butterfly is not a Batesian mimic. Nature 350:497–498.
14. Pinheiro, Carlos E. G. (1996) Palatablility and escaping ability in Neotropical butterflies: tests with wild kingbirds (''Tyrannus melancholicus'', Tyrannidae). ''Biol. J. Linn. Soc.'' '59'(4): 351–365. HTML abstract
15. But Sheppard points out that Hecht and Marien put forward a similar hypothesis ten years earlier (''J. Morph.'' '98':335-365), see Sheppard, P. M. (1969) Review of Mimicry in Plants and Animals by Wolfgang Wickler ''The Journal of Animal Ecology'' '38': 243.
16. Spindel, E. L.; J. L. Dobie,; D. F. Buxton (2005) Functional mechanisms and histologic composition of the lingual appendage in the alligator snapping turtle, Macroclemys temmincki (Troost) (Testudines: Chelydridae). ''Journal of Morphology''. '194':287 - 301.
17. Lloyd, J. E. (1965) Aggressive Mimicry in Photuris: Firefly Femmes Fatales Science 149:653-654.
18. Lloyd, J. E. (1975) Aggressive Mimicry in Photuris Fireflies: Signal Repertoires by Femmes Fatales. ''Science''. '187':452-453.
19. Willis, E. O. (1963) Is the Zone-Tailed Hawk a Mimic of the Turkey Vulture? ''The Condor'' '65':313-317.
20. Andersson, M. & Eriksson, M.O.G. 1982 Nest parasitism in goldeneyes ''Bucephala clangula'': some evolutionary aspects. American Naturalist 120, 1-16 (1982)
21. Sinervo B.; Miles D.B.; Frankino W.A.; Klukowski M.; DeNardo D.F. (2000) Testosterone, Endurance, and Darwinian Fitness: Natural and Sexual Selection on the Physiological Bases of Alternative Male Behaviors in Side-Blotched Lizards. ''Hormones and Behavior''. '38':222-233.
22. Muller, M. N.; Wrangham, R. (2002) Sexual Mimicry in Hyenas ''The Quarterly Review of Biology'' '77':3-16.
23. Williamson, G. B.; E. M. Black (1981) Mimicry in Hummingbird-Pollinated Plants? ''Ecology'' '62':494-496
24. Alexander, Victoria N. Nabokov and Insect mimicry. ''Nabokov Studies''

External links

★ Warning Colour and Mimicry Lecture outline from University College London

★ Camouflage and Mimicry in Fossils

★ Chemical Mimicry in Pollination

★ Telling the difference between Wunderpus and The Mimic Octopus