![Batesplate ArM](https://upload.wikimedia.org/wikipedia/commons/9/95/Batesplate_ArM.jpg)
In
evolutionary biology
Evolutionary biology is the subfield of biology that studies the evolutionary processes (natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life fo ...
, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. Often, mimicry functions to protect a species from predators, making it an
anti-predator adaptation. Mimicry evolves if a receiver (such as a predator) perceives the similarity between a mimic (the organism that has a resemblance) and a model (the organism it resembles) and as a result changes its behaviour in a way that provides a selective advantage to the mimic.
The resemblances that evolve in mimicry can be visual, acoustic, chemical, tactile, or electric, or combinations of these sensory modalities.
Mimicry may be to the advantage of both organisms that share a resemblance, in which case it is a form of
mutualism; or mimicry can be to the detriment of one, making it
parasitic or
competitive. The evolutionary convergence between groups is driven by the
selective action of a signal-receiver or dupe.
Birds, for example, use sight to identify palatable insects and butterflies,
whilst avoiding the noxious ones. Over time, palatable insects may evolve to resemble noxious ones, making them mimics and the noxious ones models. In the case of mutualism, sometimes both groups are referred to as "co-mimics". It is often thought that models must be more abundant than mimics, but this is not so.
Mimicry may involve numerous species; many harmless species such as hoverflies are
Batesian mimics
Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, after his work on Bu ...
of strongly defended species such as wasps, while many such well-defended species form
Müllerian mimicry rings, all resembling each other. Mimicry between prey species and their predators often involves three or more species.
In its broadest definition, mimicry can include non-living models. The specific terms masquerade and
mimesis
Mimesis (; grc, μίμησις, ''mīmēsis'') is a term used in literary criticism and philosophy that carries a wide range of meanings, including ''imitatio'', imitation, nonsensuous similarity, receptivity, representation, mimicry, the act ...
are sometimes used when the models are inanimate.
For example,
animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...
s such as
flower mantis
Flower mantises are praying mantis species that use a special form of camouflage referred to as aggressive mimicry, which they not only use to attract prey, but avoid predators as well. These insects have specific colorations and behaviors that ...
es,
planthoppers
A planthopper is any insect in the infraorder Fulgoromorpha, in the suborder Auchenorrhyncha, a group exceeding 12,500 described species worldwide. The name comes from their remarkable resemblance to leaves and other plants of their environment ...
,
comma
The comma is a punctuation mark that appears in several variants in different languages. It has the same shape as an apostrophe or single closing quotation mark () in many typefaces, but it differs from them in being placed on the baseline ...
and
geometer moth caterpillars resemble twigs, bark, leaves, bird droppings or flowers.
Many animals bear
eyespots, which are hypothesized to resemble the eyes of larger animals. They may not resemble any specific organism's eyes, and whether or not animals respond to them as eyes is also unclear. Nonetheless, eyespots are the subject of a rich contemporary literature. The model is usually another species, except in
automimicry, where members of the species mimic other members, or other parts of their own bodies, and in
inter-sexual mimicry, where members of one sex mimic members of the other.
![Ctenomorpha chronus02](https://upload.wikimedia.org/wikipedia/commons/6/64/Ctenomorpha_chronus02.jpg)
Mimicry can result in an
evolutionary arms race if mimicry negatively affects the model, and the model can evolve a different appearance from the mimic.
p161 Mimicry should not be confused with other forms of
convergent evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...
that occurs when species come to resemble each other by
adapting to similar lifestyles that have nothing to do with a common signal receiver. Mimics may have different models for different
life cycle stages, or they may be
polymorphic, with different individuals imitating different models, such as in
Heliconius butterflies. Models themselves may have more than one mimic, though
frequency dependent selection favours mimicry where models outnumber mimics. Models tend to be relatively closely
related
''Related'' is an American comedy-drama television series that aired on The WB from October 5, 2005, to March 20, 2006. It revolves around the lives of four close-knit sisters of Italian descent, raised in Brooklyn and living in Manhattan.
The ...
organisms,
but mimicry of vastly different species is also known. Most known mimics are
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
s,
though many other examples including
vertebrates
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...
are also known.
Plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...
s and
fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...
may also be mimics, though less research has been carried out in this area.
[ Wickler, Wolfgang, 1998. "Mimicry". '']Encyclopædia Britannica
The (Latin for "British Encyclopædia") is a general knowledge English-language encyclopaedia. It is published by Encyclopædia Britannica, Inc.; the company has existed since the 18th century, although it has changed ownership various time ...
'', 15th edition. Macropædia 24, 144–151. https://www.britannica.com/eb/article-11910
Etymology
Use of the word
mimicry
In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. Often, mimicry f ...
dates to 1637. It
derives from the
Greek term ''mimetikos'', "imitative", in turn from ''mimetos'', the verbal adjective of ''mimeisthai'', "to imitate". Originally used to describe people, "mimetic" was used in zoology from 1851, "mimicry" from 1861.
Classification
Many types of mimicry have been described. An overview of each follows, highlighting the similarities and differences between the various forms. Classification is often based on
function with respect to the mimic (e.g., avoiding harm). Some cases may belong to more than one class, e.g., automimicry and aggressive mimicry are not mutually exclusive, as one describes the species relationship between model and mimic, while the other describes the function for the mimic (obtaining food). The terminology used is not without debate and attempts to clarify have led to new terms being included. The term "masquerade" is sometimes used when the model is inanimate but it is differentiated from "crypsis" in its strict sense by the potential response of the signal receiver. In crypsis the receiver is assumed to not respond while a masquerader confuses the recognition system of the receiver that would otherwise seek the signaller. In the other forms of mimicry, the signal is not filtered out by the sensory system of the receiver. These are not mutually exclusive and in the evolution of wasp-like appearance, it has been argued that insects evolve to masquerade wasps since predatory wasps do not attack each other but this mimetic resemblance also deters vertebrate predators.
Defensive
![Macroxiphus sp cricket](https://upload.wikimedia.org/wikipedia/commons/d/d0/Macroxiphus_sp_cricket.jpg)
Defensive or protective mimicry takes place when organisms are able to avoid harmful encounters by deceiving enemies into treating them as something else.
The first three such cases discussed here entail mimicry of animals protected by
warning coloration
Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defences which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or ...
:
*
Batesian mimicry
Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, after his work on bu ...
, where a harmless mimic poses as harmful.
*
Müllerian mimicry, where two or more harmful species mutually
advertise themselves as harmful.
*
Mertensian mimicry
Emsleyan mimicry, also called Mertensian mimicry, describes an unusual type of mimicry where a deadly prey mimics a less dangerous species.
History
Emsleyan mimicry was first proposed by M. G. Emsley as a possible explanation for how a predat ...
, where a deadly mimic resembles a less harmful but lesson-teaching model.
The fourth case,
Vavilovian mimicry
In plant biology, Vavilovian mimicry (also crop mimicry or weed mimicry) is a form of mimicry in plants where a weed evolves to share one or more characteristics with a domesticated plant through generations of artificial selection. It is name ...
, where weeds resemble crops, involves humans as the agent of selection.
Batesian
![FinnBirdMimic](https://upload.wikimedia.org/wikipedia/commons/6/61/FinnBirdMimic.jpg)
In Batesian mimicry the mimic shares signals similar to the model, but does not have the attribute that makes it unprofitable to predators (e.g., unpalatability). In other words, a Batesian mimic is a
sheep in wolf's clothing. It is named after
Henry Walter Bates, an English naturalist whose work on
butterflies
Butterflies are insects in the macrolepidopteran clade Rhopalocera from the Order (biology), order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The ...
in the
Amazon rainforest
The Amazon rainforest, Amazon jungle or ; es, Selva amazónica, , or usually ; french: Forêt amazonienne; nl, Amazoneregenwoud. In English, the names are sometimes capitalized further, as Amazon Rainforest, Amazon Forest, or Amazon Jungle. ...
(described in ''
The Naturalist on the River Amazons'') was pioneering in this field of study. Mimics are less likely to be found out (for example by predators) when in low proportion to their model. This phenomenon is called
negative frequency dependent selection Frequency-dependent selection is an evolutionary process by which the fitness of a phenotype or genotype depends on the phenotype or genotype composition of a given population.
* In positive frequency-dependent selection, the fitness of a phenotyp ...
, and it applies in most forms of mimicry. Batesian mimicry can only be maintained if the harm caused to the predator by eating a model outweighs the benefit of eating a mimic. The nature of learning is weighted in favor of the mimics, for a predator that has a bad first experience with a model tends to avoid anything that looks like it for a long time, and does not re-sample soon to see whether the initial experience was a false negative. However, if mimics become more abundant than models, then the probability of a young predator having a first experience with a mimic increases. Such systems are therefore most likely to be stable where both the model and the mimic occur, and where the model is more abundant than the mimic. This is not the case in Müllerian mimicry, which is described next.
![Wasp mimicry](https://upload.wikimedia.org/wikipedia/commons/b/b5/Wasp_mimicry.jpg)
There are many Batesian mimics in the order
Lepidoptera
Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...
. ''
Consul fabius
''Consul fabius'', the tiger leafwing, is the most common and well known species of the genus ''Consul'' of subfamily Charaxinae in the brush-footed butterfly family (Nymphalidae). It is found all over the Neotropics.
Description
The length of ...
'' and ''
Eresia eunice
Eresia may refer to:
*''Eresia'', a journal edited by Enrico Arrigoni
Enrico Arrigoni (pseudonym: Frank Brand) (February 20, 1894 Pozzuolo Martesana, Province of Milan – December 7, 1986 New York City) was an Italian American individualist anar ...
'' imitate unpalatable ''
Heliconius'' butterflies such as ''
H. ismenius''.
''
Limenitis arthemis
''Limenitis arthemis,'' the red-spotted purple or white admiral, is a North American butterfly species in the cosmopolitan genus ''Limenitis''. It has been studied for its evolution of mimicry, and for the several stable hybrid wing patterns wi ...
'' imitate the poisonous pipevine swallowtail (''
Battus philenor
''Battus philenor'', the pipevine swallowtail or blue swallowtail, Retrieved April 19, 2018. is a swallowtail butterfly found in North America and Central America. This butterfly is black with iridescent-blue hindwings. They are found in many d ...
''). Several palatable moths produce ultrasonic click calls to mimic unpalatable tiger moths.
Octopuses
An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish ...
of the genus ''Thaumoctopus'' (the
mimic octopus
The mimic octopus (''Thaumoctopus mimicus'') is a species of octopus from the Indo-Pacific region. Like other octopuses, it uses its chromatophores to disguise itself with its background. However, it is noteworthy for being able to impersonate a ...
) are able to intentionally alter their body shape and coloration to resemble dangerous
sea snakes
Sea snakes, or coral reef snakes, are elapid snakes that inhabit marine environments for most or all of their lives. They belong to two subfamilies, Hydrophiinae and Laticaudinae. Hydrophiinae also includes Australasian terrestrial snakes, where ...
or
lionfish
''Pterois'' is a genus of venomous marine fish, commonly known as lionfish, native to the Indo-Pacific. Also called firefish, turkeyfish, tastyfish, or butterfly-cod, it is characterized by conspicuous warning coloration with red, white, crea ...
. In the Amazon, the
helmeted woodpecker
The helmeted woodpecker (''Celeus galeatus'') is a species of bird in the family Picidae. It has been recorded from far northeastern Argentina, southeastern Brazil, and eastern Paraguay. Its habitat is subtropical or tropical moist lowland forest ...
(''
Dryocopus galeatus''), a rare species which lives in the Atlantic Forest of Brazil, Paraguay, and Argentina, has a similar red crest, black back, and barred underside to two larger woodpeckers:
''Dryocopus lineatus'' and ''
Campephilus robustus''. This mimicry reduces attacks on ''Dryocopus galeatus'' from other animals. Scientists had falsely believed that ''D. galeatus'' was a close cousin of the other two species, because of the visual similarity, and because the three species live in the same habitat and eat similar food. Batesian mimicry also occurs in the plant kingdom, such as the
chameleon vine, which adapts its leaf shape and colour to match that of the plant it is climbing, such that its edible leaves appear to be the less desirable leaves of its host.
Müllerian
![Heliconius mimicry](https://upload.wikimedia.org/wikipedia/commons/0/0a/Heliconius_mimicry.png)
Müllerian mimicry, named for the German naturalist
Fritz Müller
Johann Friedrich Theodor Müller (31 March 1822 – 21 May 1897), better known as Fritz Müller, and also as Müller-Desterro, was a German biologist who emigrated to southern Brazil, where he lived in and near the German community of Blumenau, ...
, describes a situation where two or more species have similar warning or
aposematic signals and both share genuine
anti-predation
Anti-predator adaptations are mechanisms developed through evolution that assist prey organisms in their constant struggle against predators. Throughout the animal kingdom, adaptations have evolved for every stage of this struggle, namely by avo ...
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? Müller put forward the first explanation and mathematical model for this phenomenon: if a common predator confuses two species, individuals in both those species are more likely to survive. 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. The signal receiver also benefits by this system, despite being deceived about species identity, as it is able to generalize the pattern to potentially harmful encounters. The distinction between mimic and model that is clear in
Batesian mimicry
Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, after his work on bu ...
is also blurred. 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 makes more sense to speak of each as a ''co-mimic'' than of distinct 'mimic' and 'model' species, as their warning signals tend to converge. Also, the mimetic species may exist on a continuum from harmless to highly noxious, so Batesian mimicry grades smoothly into Müllerian convergence.
![Batesian vs Müllerian Mimicry](https://upload.wikimedia.org/wikipedia/commons/9/93/Batesian_vs_M%C3%BCllerian_Mimicry.svg)
The
monarch butterfly
The monarch butterfly or simply monarch (''Danaus plexippus'') is a milkweed butterfly (subfamily Danainae) in the family Nymphalidae. Other common names, depending on region, include milkweed, common tiger, wanderer, and black-veined brown. It ...
(''Danaus plexippus'') is a member of a Müllerian complex with the
viceroy butterfly (''Limenitis archippus''), sharing coloration patterns and display behaviour. The viceroy has
subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
with somewhat different coloration, each closely matching the local ''
Danaus
In Greek mythology, Danaus (, ; grc, Δαναός ''Danaós'') was the king of Libya. His myth is a foundation legend of Argos, one of the foremost Mycenaean cities of the Peloponnesus. In Homer's ''Iliad'', "Danaans" ("tribe of Danaus") and " ...
'' species. For example, in
Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
, the pairing is of the viceroy and the
queen butterfly
The queen butterfly (''Danaus gilippus'') is a North and South American butterfly in the family Nymphalidae with a wingspan of . It is orange or brown with black wing borders and small white forewing spots on its dorsal wing surface, and reddish ...
, whereas in
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
the viceroy resembles the
soldier butterfly. The viceroy is thus involved in three different Müllerian pairs.
This example was long believed to be Batesian, with the viceroy mimicking the monarch, but the viceroy is actually ''more'' unpalatable than the Queen.
The genus ''
Morpho
The morpho butterflies comprise many species of Neotropical butterfly under the genus ''Morpho''. This genus includes more than 29 accepted species and 147 accepted subspecies, found mostly in South America, Mexico, and Central America. ''Morph ...
'' is palatable, but some species (such as ''
M. amathonte'') are strong fliers; birds – even species that specialize in catching butterflies on the wing – find it hard to catch them. The conspicuous blue coloration shared by most ''Morpho'' species may be Müllerian,
or may be "pursuit aposematism". Since ''Morpho'' butterflies are
sexually dimorphic, the males' iridescent coloration may also relate to sexual selection. The "orange complex" of distasteful butterfly species includes the
heliconiine
The Heliconiinae, commonly called heliconians or longwings, are a subfamily of the brush-footed butterflies (family Nymphalidae). They can be divided into 45–50 genera and were sometimes treated as a separate family Heliconiidae within the Pa ...
s ''
Agraulis vanillae
The Gulf fritillary or passion butterfly (''Dione vanillae'') is a bright orange butterfly in the subfamily Heliconiinae of the family Nymphalidae. That subfamily was formerly set apart as a separate family, the Heliconiidae. The Heliconiinae a ...
'', ''
Dryadula phaetusa'', and ''
Dryas iulia
''Dryas iulia'' (often incorrectly spelled ''julia''),Lamas, G. (editor) (2004). Atlas of Neotropical Lepidoptera. Checklist: Part 4A. Hesperioidea – Papilionoidea. commonly called the Julia butterfly, Julia heliconian, the flame, or flambeau ...
''.
At least seven species of
millipedes in the genera ''
Apheloria
''Apheloria'' is a genus of flat-backed millipedes in the family Xystodesmidae, occurring in the central and southeastern United States, and ranging as far north as southern Quebec, Canada.Hoffman, Richard L. 1999. Checklist of the millipeds of ...
'' and ''
Brachoria
''Brachoria'' is a genus of polydesmidan millipedes in the family Xystodesmidae inhabiting the Eastern United States. Also known as the Appalachian mimic millipedes, at least 30 species are known, with highest diversity in the Appalachian Moun ...
'' (
Xystodesmidae
Xystodesmidae is a family of millipedes. Its members often have very small distributional areas, with many species only known from a single locality. They are found across the northern hemisphere, with peak diversity in the Appalachian Mountains, ...
) form a Müllerian mimicry ring in the eastern United States, in which unrelated polymorphic species converge on similar colour patterns where their range overlaps.
Emsleyan/Mertensian
![Lampropeltis triangulum annulata](https://upload.wikimedia.org/wikipedia/commons/2/20/Lampropeltis_triangulum_annulata.jpg)
Emsleyan
or Mertensian mimicry describes the unusual case where a deadly prey mimics a less dangerous species. It was first proposed by M. G. Emsley
as a possible explanation for how a predator can learn to avoid a very dangerous aposematic animal, such as a
coral snake
Coral snakes are a large group of elapid snakes that can be divided into two distinct groups, the Old World coral snakes and New World coral snakes. There are 16 species of Old World coral snakes, in three genera (''Calliophis'', '' Hemibungarus' ...
, when the predator is very likely to die, making learning unlikely. The theory was developed by the German biologist
Wolfgang Wickler
Wolfgang Wickler is a German zoologist, behavioral researcher and author. He led the ethology, ethological department of the Max Planck Institute for Behavioral Physiology from 1974, and he took over as director of the institute in 1975. Even aft ...
who named it after the
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ger ...
herpetologist Robert Mertens
Robert Friedrich Wilhelm Mertens (1 December 1894 – 23 August 1975) was a German herpetologist. Several taxa of reptiles are named after him.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore ...
.
The scenario is unusual, as it is usually the most harmful species that is the model. But if a predator dies on its first encounter with a deadly snake, it has no occasion to
learn
Learning is the process of acquiring new understanding, knowledge, behaviors, skills, values, attitudes, and preferences. The ability to learn is possessed by humans, animals, and some machines; there is also evidence for some kind of learnin ...
to recognize the snake's warning signals. There would then be no advantage for an extremely deadly snake in being aposematic: any predator that attacked it would be killed before it could learn to avoid the deadly prey, so the snake would be better off being camouflaged, to avoid attacks altogether. But if the predator first learnt to avoid a less deadly snake that had warning colours, the deadly species could then profit (be attacked less often) by mimicking the less dangerous snake.
[
Some harmless milk snake (''Lampropeltis triangulum'') subspecies, the moderately toxic ]false coral snakes
False coral may refer to many species of snakes, including:
*several species of the genus ''Erythrolamprus'':
** ''Erythrolamprus aesculapii'', a mildly venomous colubrid snake species found in South America.
** ''Erythrolamprus bizona'', a harmle ...
(genus ''Erythrolamprus''), and the deadly coral snakes (genus '' Micrurus'') all have a red background color with black and white / yellow rings. In this system, both the milk snakes and the deadly coral snakes are mimics, whereas the false coral snakes are the model.[
]
Wasmannian
In Wasmannian mimicry, the mimic resembles a model that it lives along with in a nest or colony. Most of the models here are social
Social organisms, including human(s), live collectively in interacting populations. This interaction is considered social whether they are aware of it or not, and whether the exchange is voluntary or not.
Etymology
The word "social" derives from ...
insects such as ants, termites, bees and wasps.
Vavilovian
Vavilovian mimicry is found in weeds that come to share characteristics with a domesticated plant
Domestication is a sustained multi-generational relationship in which humans assume a significant degree of control over the reproduction and care of another group of organisms to secure a more predictable supply of resources from that group. A ...
through artificial selection
Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant m ...
. It is named after Russian botanist
Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek wo ...
and geneticist Nikolai Vavilov. Selection against the weed may occur either by manually killing the weed, or by separating its seeds from those of the crop by winnowing.
Vavilovian mimicry presents an illustration of unintentional (or rather 'anti-intentional') selection by man. Weeders do not want to select weeds and their seeds that look increasingly like cultivated plants, yet there is no other option. For example, early barnyard grass, ''Echinochloa oryzoides
''Echinochloa oryzoides'' is a species of grass known by the common name early barnyard grass. Its origin is not certain but it may be Eurasia. The grass has been identified as a major weed of rice paddies and has been known to mimic
MIMIC, kno ...
'', is a weed in rice
Rice is the seed of the grass species ''Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima
''Oryza glaberrima'', commonly known as African rice, is one of the two domesticated rice species. It was first domesticated and grown i ...
fields and looks similar to rice; its seeds are often mixed in rice and have become difficult to separate through Vavilovian mimicry. Vavilovian mimics may eventually be domesticated themselves, as in the case of rye in wheat; Vavilov called these weed-crops ''secondary crops''.[
Vavilovian mimicry can be classified as ]defensive mimicry
In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. Often, mimicry f ...
, in that the weed mimics a protected species. This bears strong similarity to Batesian mimicry in that the weed does not share the properties that give the model its protection, and both the model and the dupe (in this case people) are harmed by its presence. There are some key differences, though; in Batesian mimicry
Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, after his work on bu ...
, the model and signal receiver are enemies (the predator would eat the protected species if it could), whereas here the crop and its human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
growers are in a mutualistic relationship: the crop benefits from being dispersed and protected by people, despite being eaten by them. In fact, the crop's only "protection" relevant here is its usefulness to humans. Secondly, the weed is not eaten, but simply destroyed. The only motivation for killing the weed is its effect on crop yields. Finally, this type of mimicry does not occur in ecosystems unaltered by humans.
Gilbertian
Gilbertian mimicry involves only two species. The potential host (or prey) drives away its parasite (or predator) by mimicking it, the reverse of host-parasite aggressive mimicry. It was coined by Pasteur as a phrase for such rare mimicry systems, and is named after the American ecologist
Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...
.
Gilbertian mimicry occurs in the genus ''Passiflora
''Passiflora'', known also as the passion flowers or passion vines, is a genus of about 550 species of flowering plants, the type genus of the family Passifloraceae.
They are mostly tendril-bearing vines, with some being shrubs or trees. They ...
''. The leaves of this plant contain toxins that deter herbivorous animals. However, some '' Heliconius'' butterfly larvae have evolved enzymes that break down these toxins, allowing them to specialize on this genus. This has created further selection pressure on the host plants, which have evolved stipules
In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...
that mimic mature ''Heliconius'' eggs near the point of hatching. These butterflies tend to avoid laying eggs near existing ones, which helps avoid exploitative intraspecific competition between caterpillars — those that lay on vacant leaves provide their offspring with a greater chance of survival. Most ''Heliconius'' larvae are cannibalistic, meaning that on leaves older eggs hatch first and eat the new arrivals. Thus, it seems that such plants have evolved egg dummies under selection pressure from these grazing herbivore enemies. In addition, the decoy eggs are also nectaries, attracting predators of the caterpillars such as ants and wasps as a further defence.
Browerian
Browerian mimicry, named after Lincoln P. Brower
Lincoln Pierson Brower (September 10, 1931 – July 17, 2018) was an American entomologist and ecologist, known for his work on monarch butterflies through six decades, including on their automimicry, chemical ecology and conservation. G. Pasteu ...
and Jane Van Zandt Brower, is a postulated form of ''automimicry''; where the model belongs to the same species as the mimic. This is the analogue of Batesian mimicry within a single species, and occurs when there is a palatability spectrum within a population. Examples include the monarch
A monarch is a head of stateWebster's II New College DictionarMonarch Houghton Mifflin. Boston. 2001. p. 707. Life tenure, for life or until abdication, and therefore the head of state of a monarchy. A monarch may exercise the highest authority ...
and the queen
Queen or QUEEN may refer to:
Monarchy
* Queen regnant, a female monarch of a Kingdom
** List of queens regnant
* Queen consort, the wife of a reigning king
* Queen dowager, the widow of a king
* Queen mother, a queen dowager who is the mother ...
from the subfamily Danainae, which feed on milkweed
''Asclepias'' is a genus of herbaceous, perennial, flowering plants known as milkweeds, named for their latex, a milky substance containing cardiac glycosides termed cardenolides, exuded where cells are damaged. Most species are toxic to humans ...
species of varying toxicity. These species store toxins from its host plant, which are maintained even in the adult (imago
In biology, the imago (Latin for "image") is the last stage an insect attains during its metamorphosis, its process of growth and development; it is also called the imaginal stage, the stage in which the insect attains maturity. It follows the f ...
) form. As levels of toxin vary depending on diet during the larval stage, some individuals are more toxic than others. Less palatable organisms, therefore, mimic more dangerous individuals, with their likeness already perfected.
This is not always the case, however. In sexually dimorphic species, one sex may be more of a threat than the other, which could mimic the protected sex. Evidence for this possibility is provided by the behaviour of a monkey from Gabon
Gabon (; ; snq, Ngabu), officially the Gabonese Republic (french: République gabonaise), is a country on the west coast of Central Africa. Located on the equator, it is bordered by Equatorial Guinea to the northwest, Cameroon to the north ...
, which regularly ate male moths of the genus ''Anaphe'', but promptly stopped after it tasted a noxious female.
Aggressive
Predators
Aggressive mimicry is found in predators or parasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...
s that share some of the characteristics of a harmless species, allowing them to avoid detection by their prey or host
A host is a person responsible for guests at an event or for providing hospitality during it.
Host may also refer to:
Places
* Host, Pennsylvania, a village in Berks County
People
*Jim Host (born 1937), American businessman
* Michel Host ...
; this can be compared with the story of the wolf in sheep's clothing
A wolf in sheep's clothing is an idiom of Biblical origin used to describe those playing a role contrary to their real character with whom contact is dangerous, particularly false teachers. Much later, the idiom has been applied by zoologists to v ...
as long as it is understood that no conscious deceptive intent is involved. The mimic may resemble the prey or host itself, or another organism that 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: Individuals, populations and communities'' (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 spider
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...
s, amongst which aggressive mimicry is quite common both in luring prey and disguising stealthily approaching predators. One case is the golden orb weaver
''Nephila'' is a genus of araneomorph spiders noted for the impressive webs they weave. ''Nephila'' consists of numerous species found in warmer regions around the world. They are commonly called golden silk orb-weavers, golden orb-weavers, gian ...
(''Nephila clavipes''), which spins a conspicuous golden colored web in well-lit areas. Experiments show that bees are able to associate the webs with danger when the yellow pigment is not present, as occurs in less well-lit areas where the web is much harder to see. Other colours were also learned and avoided, but bees seemed least able to effectively associate yellow-pigmented webs with danger. Yellow is the colour of many nectar-bearing flowers, however, so perhaps avoiding yellow is not worthwhile. Another form of mimicry is based not on colour but pattern. Species such as the silver argiope (''Argiope argentata
''Argiope argentata'', commonly known as the silver argiope due to the silvery color of its cephalothorax, is a member of the orb-weaver spider family Araneidae. This species resides in arid and warm environments in North America, Central America ...
'') employ prominent patterns in the middle of their webs, such as zigzags. These may reflect ultraviolet light, and mimic the pattern seen in many flowers known as nectar guides. Spiders change their web day to day, which can be explained by the ability of bees to remember web patterns. Bees are able to associate a certain pattern with a spatial location, meaning the spider must spin a new pattern regularly or suffer diminishing prey capture.
Another case is where males are lured towards what seems to be a sexually receptive
Animal sexual behaviour takes many different forms, including within the same species. Common mating or reproductively motivated systems include monogamy, polygyny, polyandry, polygamy and promiscuity. Other sexual behaviour may be reproduc ...
female. The model in this situation is the same species as the dupe. Beginning in the 1960s, James E. Lloyd's investigation of female fireflies of the genus ''Photuris
''Photuris'' is a genus of fireflies (beetles of the family Lampyridae). These are the ''femme fatale'' lightning bugs of North America. This common name refers to a behavior of the adult females of these predatory beetles; they engage in aggr ...
'' revealed they emit the same light signals that females of the genus '' Photinus'' use as a mating signal. Further research showed male fireflies from several different genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
are attracted to these "femmes fatales
A ''femme fatale'' ( or ; ), sometimes called a maneater or vamp, is a stock character of a mysterious, beautiful, and seductive woman whose charms ensnare her lovers, often leading them into compromising, deadly traps. She is an archetype of ...
", 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.
The listrosceline katydid
Insects in the family Tettigoniidae are commonly called katydids (especially in North America), or bush crickets. They have previously been known as "long-horned grasshoppers". More than 8,000 species are known. Part of the suborder Ensifera, t ...
'' Chlorobalius leucoviridis'' of inland Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
is capable of attracting male cicadas of the tribe Cicadettini by imitating the species-specific reply clicks of sexually receptive female cicadas. This example of acoustic aggressive mimicry is similar to the ''Photuris'' firefly case in that the predator's mimicry is remarkably versatile – playback experiments show that ''C. leucoviridis'' is able to attract males of many cicada species, including cicadettine cicadas from other continents, even though cicada mating signals are species-specific.
Some carnivorous plant
Carnivorous plants are plants that derive some or most of their nutrients from trapping and consuming animals or protozoans
Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryot ...
s may also be able to increase their rate of capture through mimicry.
Luring is not a necessary condition however, as the predator still has a significant advantage simply by 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 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
The bluestreak cleaner wrasse, ''Labroides dimidiatus'', is one of several species of cleaner wrasses found on coral reefs from Eastern Africa and the Red Sea to French Polynesia. Like other cleaner wrasses, it eats parasites and dead tissue o ...
(''Labroides dimidiatus''), is the unknowing model of a mimetic species, the sabre-toothed blenny ( ''Aspidontus taeniatus''). This wrasse
The wrasses are a family, Labridae, of marine fish, many of which are brightly colored. The family is large and diverse, with over 600 species in 81 genera, which are divided into 9 subgroups or tribes.
They are typically small, most of them le ...
resides in coral reef
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.
Co ...
s in the Indian
Indian or Indians may refer to:
Peoples South Asia
* Indian people, people of Indian nationality, or people who have an Indian ancestor
** Non-resident Indian, a citizen of India who has temporarily emigrated to another country
* South Asia ...
and the Pacific Oceans, and is recognized by other fishes that then let it clean them. Its imposter, a species of blenny
Blenny (from the Greek and , mucus, slime) is a common name for many types of fish, including several families of percomorph marine, brackish, and some freshwater fish sharing similar morphology and behaviour. Six families are considered "true ...
, lives in the Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...
—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. Fish grazed
In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to roam around and consume wild vegetations in order to convert the otherwise indigestible (by human gut) cellulose within grass and other f ...
on 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, so both are affected. Due to victims' ability to discriminate between foe and helper, the blennies have evolved close similarity, right down to the regional level.
Another interesting example that does not involve any luring is the zone-tailed hawk
The zone-tailed hawk (''Buteo albonotatus'') is a medium-sized buzzard, hawk of warm, dry parts of the Americas. It is somewhat similar in plumage and flight style to a common scavenger, the turkey vulture, and may benefit from being able to blen ...
, which resembles the turkey vulture
The turkey vulture (''Cathartes aura'') is the most widespread of the New World vultures. One of three species in the genus ''Cathartes'' of the family Cathartidae, the turkey vulture ranges from southern Canada to the southernmost tip of South ...
. It flies amongst the vultures, suddenly breaking from the formation and ambushing its prey. Here the hawk's presence is of no evident significance to the vultures, affecting them neither negatively or positively.
Parasites
Parasites can also be aggressive mimics, though the situation is somewhat different from those outlined previously. Some predators have a feature that draws prey; parasites can also mimic their hosts' natural prey, but are eaten themselves, a pathway into their host. '' Leucochloridium'', a genus of flatworm
The flatworms, flat worms, Platyhelminthes, or platyhelminths (from the Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") are a phylum of relatively simple bilaterian, unsegment ...
, matures in the digestive system of songbirds, their eggs then passing out of the bird in the faeces. They are then taken up by ''Succinea
''Succinea'', common name the amber snails, is a large genus of small, air-breathing land snails, terrestrial pulmonate gastropod molluscs in the family Succineidae. MolluscaBase eds. (2021). MolluscaBase. Succinea Draparnaud, 1801. Access ...
'', a terrestrial snail. The eggs develop in this intermediate host
In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' (symbiont). The guest is typically provided with nourishment and shelter. Examples include a ...
, and must then find a suitable bird to mature in. Since the host birds do not eat snails, the sporocyst has another strategy to reach its host's intestine. They are brightly coloured and move in a pulsating fashion. A sporocyst-sac pulsates in the snail's eye stalks, coming to resemble an irresistible meal for a songbird. In this way, it can bridge the gap between hosts, allowing it to complete its life cycle.[ A nematode ('']Myrmeconema neotropicum
''Myrmeconema neotropicum'' is a tetradonematid nematode parasite. It appears to induce fruit mimicry in the tropical ant. Presently the only known host species is ''Cephalotes atratus'', a South American ant with a black abdomen. Upon infection ...
'') changes the colour of the abdomen of workers of the canopy ant ''Cephalotes atratus'' to make it appear like the ripe fruits of ''Hyeronima alchorneoides''. It also changes the behaviour of the ant so that the gaster (rear part) is held raised. This presumably increases the chances of the ant being eaten by birds. The droppings of birds are collected by other ants and fed to their brood, thereby helping to spread the nematode.
In an unusual case, planidium larvae of some beetles of the genus ''Meloe
The blister beetle genus ''Meloe'' is a large, widespread group commonly referred to as oil beetles. They are known as "oil beetles" because they release oily droplets of hemolymph from their joints when disturbed; this contains cantharidin, a ...
'' form a group and produce a pheromone that mimics the sex attractant of its host bee
Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyly, monophyletic lineage within the ...
species. When a male bee arrives and attempts to mate with the mass of larvae, they climb onto his abdomen. From there, they transfer to a female bee, and from there to the bee nest to parasitize the bee larvae.
Host-parasite mimicry is a two species system where a parasite mimics its own host. Cuckoo
Cuckoos are birds in the Cuculidae family, the sole taxon in the order Cuculiformes . The cuckoo family includes the common or European cuckoo, roadrunners, koels, malkohas, couas, coucals and anis. The coucals and anis are sometimes separ ...
s are a canonical example of brood parasitism, a form of parasitism where the mother has its offspring raised by another unwitting individual, often from a different species, cutting down the biological mother's parental investment
Parental investment, in evolutionary biology and evolutionary psychology, is any parental expenditure (e.g. time, energy, resources) that benefits offspring.Clutton-Brock, T.H. 1991. ''The Evolution of Parental Care''. Princeton, NJ: Princeton ...
in the process. The ability to lay eggs that mimic the host eggs is the key adaptation
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the po ...
. The adaptation to different hosts is inherited through the female line in so-called gentes (gens, singular). Cases of ''intraspecific'' brood parasitism, where a female lays in a conspecific's nest, as illustrated by the goldeneye duck (''Bucephala clangula''), do not represent a case of mimicry. A different mechanism is chemical mimicry, as seen in the parasitic butterfly ''Phengaris rebeli
''Phengaris rebeli'' (formerly ''Maculinea rebeli''), common name mountain Alcon blue, is a species of butterfly in the family Lycaenidae. It was first found and described in Styria, Austria, on Mount Hochschwab around 1700. Although it was in ...
'', which parasitizes the ant species ''Myrmica schencki
''Myrmica schencki'' is a species of ant in the genus '' Myrmica''.
Distribution and habitat
''Myrmica schencki'' is distributed across Europe (from Great Britain, Sweden, Finland in the North to Spain, Italy and the Balkans in the South), the C ...
'' by releasing chemicals that fool the worker ants to believe that the caterpillar larvae are ant larvae, and enable the ''P. rebeli'' larvae to be brought directly into the ''M. schencki'' nest. Parasitic (cuckoo) bumblebees (formerly ''Psithyrus
Cuckoo bumblebees are members of the subgenus ''Psithyrus'' in the bumblebee genus ''Bombus''. Until recently, the 28 species of ''Psithyrus'' were considered to constitute a separate genus. They are a specialized socially parasitic lineage whi ...
'', now included in ''Bombus
A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only extant group in the tribe Bombini, though a few extinct related gener ...
'') resemble their hosts more closely than would be expected by chance, at least in areas like Europe where parasite-host co-speciation is common. However, this is explainable as Müllerian mimicry, rather than requiring the parasite's coloration to deceive the host and thus constitute aggressive mimicry.
Reproductive
Reproductive mimicry occurs when the actions of the dupe directly aid in the mimic's reproduction
Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual or ...
. This is common in plants with deceptive flowers that do not provide the reward they seem to offer and it may occur in Papua New Guinea fireflies, in which the signal of ''Pteroptyx effulgens'' is used by ''P. tarsalis'' to form aggregations to attract females. Other forms of mimicry have a reproductive component, such as Vavilovian mimicry
In plant biology, Vavilovian mimicry (also crop mimicry or weed mimicry) is a form of mimicry in plants where a weed evolves to share one or more characteristics with a domesticated plant through generations of artificial selection. It is name ...
involving seeds, vocal mimicry in birds, and aggressive and Batesian mimicry in brood parasite-host systems.
Bakerian and Dodsonian
Bakerian mimicry, named after Herbert G. Baker
Herbert George Baker (February 23, 1920 – July 2, 2001) was a British-American botanist and evolutionary ecologist who was an authority on pollination biology and breeding systems of angiosperms. He described what became known as "Baker's rule ...
, is a form of automimicry where female flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...
s mimic male flowers of their own species, cheating pollinators out of a reward. This reproductive mimicry may not be readily apparent as members of the same species may still exhibit some degree of sexual dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
. It is common in many species of Caricaceae
The Caricaceae are a family of flowering plants in the order Brassicales, found primarily in tropical regions of Central and South America and Africa. They are usually short-lived evergreen pachycaul shrubs or small to medium-sized trees growi ...
.
Dodsonian mimicry, named after Calaway H. Dodson
Calaway Homer Dodson (December 17, 1928 – August 9, 2020) was an American botanist, orchidologist, and taxonomist.
Biography
Dodson was born in Selma, California. He specialized in orchidology very early in his career. Over the course of hi ...
, is a form of reproductive floral mimicry where the model belongs to a different species than the mimic. By providing similar sensory signals as the model flower, it can lure its pollinators. Like Bakerian mimics, no nectar is provided. ''Epidendrum ibaguense
''Epidendrum ibaguense'' (pronounced ee-bah-GAIN-say) is a species of epiphytic orchid of the genus Epidendrum which occurs in Trinidad, French Guiana, Venezuela, Colombia and Northern Brazil.
Taxonomy
According to Reichenbach, ''E. ibag ...
'' (Orchidaceae
Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant.
Along with the Asteraceae, they are one of the two largest families of flowering ...
) resembles flowers of ''Lantana camara
''Lantana camara'' (common lantana) is a species of flowering plant within the verbena family (Verbenaceae), native to the American tropics. It is a very adaptable species, which can inhabit a wide variety of ecosystems; once it has been introduc ...
'' and ''Asclepias curassavica
''Asclepias curassavica'', commonly known as tropical milkweed, is a flowering plant species of the milkweed genus, ''Asclepias''. It is native to the American tropics and has a pantropical distribution as an introduced species. Other common nam ...
'', and is pollinated by monarch butterflies and perhaps hummingbird
Hummingbirds are birds native to the Americas and comprise the biological family Trochilidae. With about 361 species and 113 genera, they occur from Alaska to Tierra del Fuego, but the vast majority of the species are found in the tropics aro ...
s. Similar cases are seen in some other species of the same family. The mimetic species may still have pollinators of its own though. For example, a lamellicorn beetle, which usually pollinates correspondingly colored ''Cistus
''Cistus'' (from the Greek ''kistos'') is a genus of flowering plants in the rockrose family Cistaceae, containing about 20 species (Ellul ''et al.'' 2002). They are perennial shrubs found on dry or rocky soils throughout the Mediterranean region ...
'' flowers, is also known to aid in pollination of ''Ophrys
The genus ''Ophrys'' is a large group of orchids from the alliance Orchis in the subtribe Orchidinae. They are widespread across much of Europe, North Africa, Caucasus, the Canary Islands, and the Middle East as far east as Turkmenistan.
These p ...
'' species that are normally pollinated by bees.
Pseudocopulation
Pseudocopulation occurs when a flower mimics a female
Female (Venus symbol, symbol: ♀) is the sex of an organism that produces the large non-motile ovum, ova (egg cells), the type of gamete (sex cell) that fuses with the Sperm, male gamete during sexual reproduction.
A female has larger gamet ...
of a certain insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
species, inducing the male
Male (symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization.
A male organism cannot reproduce sexually without access to ...
s to try to copulate with the flower. This is much like the aggressive mimicry in fireflies described previously, but with a more benign outcome for the pollinator. This form of mimicry has been called ''Pouyannian mimicry'', after Maurice-Alexandre Pouyanne, who first described the phenomenon. It is most common in orchids, which mimic females of the order Hymenoptera
Hymenoptera is a large order (biology), order of insects, comprising the sawfly, sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are Par ...
(generally bees and wasps), and may account for around 60% of pollinations.[Van der Pijl, L., Dodson, C. H. (1966) ''Orchid Flowers; Their Pollination and Evolution''. Coral Gables, Florida, USA, Univ. Miami Press.] Depending on the morphology of the flower, a pollen sac called a pollinia is attached to the head or abdomen of the male. This is then transferred to the stigma of the next flower the male tries to inseminate, resulting in pollination. Visual mimicry is the most obvious sign of this deception for humans, but the visual aspect may be minor or non-existent. It is the senses of touch and olfaction
The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste.
In humans, it ...
that are most important.
Inter-sexual mimicry
Inter-sexual mimicry occurs when individuals of one sex in a species mimic members of the opposite sex to facilitate sneak mating. An example is the three male forms of the marine isopod
Isopoda is an order of crustaceans that includes woodlice and their relatives. Isopods live in the sea, in fresh water, or on land. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed limbs on the thorax, an ...
''Paracerceis sculpta
''Paracerceis sculpta'' is a species of marine isopod between and in length. The species lives mainly in the intertidal zone, and is native to the Northeast Pacific from Southern California to Mexico, but has since been introduced species, int ...
''. Alpha males are the largest and guard a harem of females. Beta males mimic females and manage to enter the harem of females without being detected by the alpha males allowing them to mate. Gamma males are the smallest males and mimic juveniles. This also allows them to mate with the females without the alpha males detecting them. Similarly, among common side-blotched lizard
The common side-blotched lizard (''Uta stansburiana'') is a species of side-blotched lizard in the family Phrynosomatidae. The species is native to dry regions of the western United States and northern Mexico. It is notable for having a unique fo ...
s, some males mimic the yellow throat coloration and even mating rejection behaviour of the other sex to sneak matings with guarded females. These males look and behave like unreceptive females. This strategy
Strategy (from Greek στρατηγία ''stratēgia'', "art of troop leader; office of general, command, generalship") is a general plan to achieve one or more long-term or overall goals under conditions of uncertainty. In the sense of the "art ...
is effective against "usurper" males with orange throats, but ineffective against blue throated "guarder" males, which chase them away. Female spotted hyena
The spotted hyena (''Crocuta crocuta''), also known as the laughing hyena, is a hyena species, currently classed as the sole extant member of the genus ''Crocuta'', native to sub-Saharan Africa. It is listed as being of least concern by the IUC ...
s have pseudo-penis A pseudo-penis is any structure found on an animal that, while superficially appearing to be a penis, is derived from a different developmental path.
Mammals
In mammals, all intact developmentally typical males have a penis, but the clitoris in ...
es that make them look like males.
Automimicry
Automimicry or intraspecific mimicry occurs within a single species. One form of such mimicry is where one part of an organism's body resembles another part. For example, the tails of some snakes resemble their heads; they move backwards when threatened and present the predator with the tail, improving their chances of escape without fatal harm. Some fishes have eyespots near their tails, and when mildly alarmed swim slowly backwards, presenting the tail as a head. Some insects such as some lycaenid
Lycaenidae is the second-largest family of butterflies (behind Nymphalidae, brush-footed butterflies), with over 6,000 species worldwide, whose members are also called gossamer-winged butterflies. They constitute about 30% of the known butterfl ...
butterflies have tail patterns and appendages of various degrees of sophistication that promote attacks at the rear rather than at the head. Several species of pygmy owl bear "false eyes" on the back of the head, misleading predators into reacting as though they were the subject of an aggressive stare.
Some writers use the term "automimicry" when the mimic imitates other morphs within the same species. For example, in a species where males mimic females or vice versa, this may be an instance of sexual mimicry Sexual mimicry occurs when one sex mimics the opposite sex in its behavior, appearance, or chemical signalling. It is more commonly seen within invertebrate species, although sexual mimicry is also seen among vertebrates such as spotted hyenas. Sexu ...
in evolutionary game theory. Examples are found in some species of birds, fishes, and lizards. Quite elaborate strategies along these lines are known, such as the well-known "scissors, paper, rock" mimicry in '' Uta stansburiana'', but there are qualitatively different examples in many other species, such as some ''Platysaurus
''Platysaurus'' is a genus of lizards, commonly known as flat lizards for their flat backs, in the family Cordylidae.
Geographic range
All species in the genus ''Platysaurus'' live in isolated populations in southern Africa. They are found in ...
''.
Many species of insects are toxic or distasteful when they have fed on certain plants that contain chemicals of particular classes, but not when they have fed on plants that lack those chemicals. For instance, some species of the subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...
Danainae feed on various species of the Asclepiadoideae in the family Apocynaceae
Apocynaceae (from ''Apocynum'', Greek for "dog-away") is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines, commonly known as the dogbane family, because some taxa were used as dog poison Members of the ...
, which render them poisonous and emetic to most predators. Such insects frequently are aposematically coloured and patterned. When feeding on innocuous plants however, they are harmless and nutritious, but a bird that once has sampled a toxic specimen is unlikely to eat harmless specimens that have the same aposematic coloration. When regarded as mimicry of toxic members of the same species, this too may be seen as automimicry.
Some species of caterpillar, such as many hawkmoths ( Sphingidae), have eyespots on their anterior abdominal segments. When alarmed, they retract the head and the thoracic segments into the body, leaving the apparently threatening large eyes at the front of the visible part of the body.
Many insects have filamentous "tails" at the ends of their wings and patterns of markings on the wings themselves. These combine to create a "false head". This misdirects predators such as birds and jumping spiders ( Salticidae). Spectacular examples occur in the hairstreak
The subfamily Theclinae is a group of butterflies, often referred to as hairstreaks, with some species instead known as elfins or by other names. The group is part of the family Lycaenidae, the "gossamer-winged butterflies". There are many tropi ...
butterflies; when perching on a twig or flower, they commonly do so upside down and shift their rear wings repeatedly, causing antenna-like movements of the "tails" on their wings. Studies of rear-wing damage support the hypothesis that this strategy is effective in deflecting attacks from the insect's head.
Other forms
Some forms of mimicry do not fit easily within the classification given above. Floral mimicry is induced by the discomycete fungus
Discomycetes is a former taxonomic class of Ascomycete fungi which contains all of the cup, sponge and brain fungi and some club-like fungi. It includes typical cup fungi like the scarlet elf cup and the orange peel fungus, and fungi with frui ...
''Monilinia vaccinii-corymbosi
''Monilinia'' is a genus of fungi in the family Sclerotiniaceae.
Monilinia fungi are pathogens to Rosaceae and Ericaceae and often cause major losses to crops. The genus is sometimes divided into two sections based on whether they possess disjun ...
''. In this case, a fungal plant pathogen
Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomyc ...
infects leaves
A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
of blueberries
Blueberries are a widely distributed and widespread group of perennial flowering plants with blue or purple berries. They are classified in the section ''Cyanococcus'' within the genus ''Vaccinium''. ''Vaccinium'' also includes cranberries, bi ...
, causing them to secrete sugars, in effect mimicking the nectar
Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists ...
of flowers. To the naked eye the leaves do not look like flowers, yet they still attract pollinating insects like bees using an ultraviolet signal. This case is unusual, in that the fungus benefits from the deception but it is the leaves that act as mimics, being harmed in the process. It is similar to host-parasite mimicry, but the host does not receive the signal. It has something in common with automimicry, but the plant does not benefit from the mimicry, and the action of the pathogen is required to produce it.[
]
Evolution
It is widely accepted that mimicry evolves as a positive adaptation. The lepidopterist
Lepidopterology ()) is a branch of entomology concerning the scientific study of moths and the three superfamilies of butterflies. Someone who studies in this field is a lepidopterist or, archaically, an aurelian.
Origins
Post-Renaissance, t ...
and novelist
A novelist is an author or writer of novels, though often novelists also write in other genres of both fiction and non-fiction. Some novelists are professional novelists, thus make a living writing novels and other fiction, while others aspire to ...
Vladimir Nabokov however argued that although natural selection might stabilize a "mimic" form, it would not be necessary to create it.
The most widely accepted model used to explain the evolution of mimicry in butterflies is the two-step hypothesis. The first step involves mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mi ...
in modifier gene
Epistasis is a phenomenon in genetics in which the effect of a gene mutation is dependent on the presence or absence of mutations in one or more other genes, respectively termed modifier genes. In other words, the effect of the mutation is dep ...
s that regulate a complex cluster of linked genes that cause large changes in morphology. The second step consists of selections on genes with smaller phenotypic
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ...
effects, creating an increasingly close resemblance. This model is supported by empirical evidence that suggests that a few single point mutations cause large phenotypic effects, while numerous others produce smaller effects. Some regulatory elements collaborate to form a supergene
A supergene is a chromosomal region encompassing multiple neighboring genes that are inherited together because of close genetic linkage, i.e. much less recombination than would normally be expected. This mode of inheritance can be due to genomic ...
for the development of butterfly color patterns. The model is supported by computational simulation
A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of Conceptual model, models; the model represents the key characteristics or behaviors of the selected system or proc ...
s of population genetics
Population genetics is a subfield of genetics that deals with genetic differences within and between populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and pop ...
. The Batesian mimicry in ''Papilio polytes'' is controlled by the '' doublesex'' gene.
Some mimicry is imperfect. Natural selection drives mimicry only far enough to deceive predators. For example, when predators avoid a mimic that imperfectly resembles a coral snake, the mimic is sufficiently protected.
Convergent evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...
is an alternative explanation for why organisms such as coral reef fish and benthic marine invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
s such as sponge
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...
s and nudibranchs have come to resemble each other.
See also
* Biomimicry
Biomimetics or biomimicry is the emulation of the models, systems, and elements of nature for the purpose of solving complex human problems. The terms "biomimetics" and "biomimicry" are derived from grc, βίος (''bios''), life, and μίμησ ...
* Chemical mimicry
* Locomotor mimicry Locomotor mimicry is a subtype of Batesian mimicry in which animals avoid predation by mimicking the movements of another species phylogenetically separated. This can be in the form of mimicking a less desirable species or by mimicking the predator ...
* Molecular mimicry Molecular mimicry is defined as the theoretical possibility that sequence similarities between foreign and self-peptides are sufficient to result in the cross-activation of autoreactive T or B cells by pathogen-derived peptides. Despite the preva ...
* Preadaptation
Exaptation and the related term co-option describe a shift in the function of a trait during evolution. For example, a trait can evolve because it served one particular function, but subsequently it may come to serve another. Exaptations are common ...
* Semiotics
Semiotics (also called semiotic studies) is the systematic study of sign processes ( semiosis) and meaning making. Semiosis is any activity, conduct, or process that involves signs, where a sign is defined as anything that communicates something ...
* Mimic octopus
The mimic octopus (''Thaumoctopus mimicus'') is a species of octopus from the Indo-Pacific region. Like other octopuses, it uses its chromatophores to disguise itself with its background. However, it is noteworthy for being able to impersonate a ...
Notes
References
Further reading
* (a supplement of volume 131 of the journal '' American Naturalist'' dedicated to E. B. Ford
Edmund Brisco "Henry" Ford (23 April 1901 – 2 January 1988) was a British ecological genetics, ecological geneticist. He was a leader among those British biologists who investigated the role of natural selection in nature. As a schoolboy Ford ...
).
*
* Cott, H. B.
Hugh Bamford Cott (6 July 1900 – 18 April 1987) was a British zoologist, an authority on both natural and military camouflage, and a scientific illustrator and photographer. Many of his field studies took place in Africa, where he was especia ...
(1940) ''Adaptive Coloration in Animals
''Adaptive Coloration in Animals'' is a 500-page textbook about camouflage, warning coloration and mimicry by the Cambridge zoologist Hugh Cott, first published during the Second World War in 1940; the book sold widely and made him famous.
The ...
''. Methuen and Co, London,
*
* Edmunds, M. 1974. ''Defence in Animals: a survey of anti-predator defences''. Harlow, Essex and New York, Longman. .
*
* Owen, D. (1980) ''Camouflage and Mimicry''. Oxford University Press, .
*
* Ruxton, G. D.; Speed, M. P.; Sherratt, T. N. (2004). ''Avoiding Attack: the evolutionary ecology of crypsis, warning signals and mimicry''. Oxford, Oxford University Press. .
*Stevens, M. (2016). ''Cheats and deceits: how animals and plants exploit and mislead''. Oxford University Press,
*
*
* Wickler, W. (1968) ''Mimicry in Plants and Animals'' (translated from the German), McGraw-Hill, New York. .
Children's
* Hoff, M. K. (2003) ''Mimicry and Camouflage''. Creative Education. Mankato, Minnesota, USA, Great Britain. .
External links
Warning colour and mimicry
• Lecture outline from University College London
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Camouflage and Mimicry in Fossils
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Mimicry
In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. Often, mimicry f ...
Polymorphism (biology)
Camouflage
Warning coloration