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Aggressive mimicry is a form of mimicry in which predators, parasites or parasitoids share similar signals with a harmless model, allowing them to avoid being correctly identified by their prey or host. In its broadest sense, it could include various types of exploitation, as when an orchid exploits a male insect by mimicking a sexually receptive female (see pseudocopulation), but will here be restricted to forms of exploitation involving feeding. An alternative term Peckhamian mimicry (after George and Elizabeth Peckham) has also been suggested,〔 but it is seldom used.〔Pasteur (1982) describes the term as redundant, and points out that there are many different forms of aggressive mimicry. The term was also used earlier by Bates (1862) and Kirby & Spence (1823).〕 The metaphor of a wolf in sheep's clothing can be used as an analogy, but with the caveat that mimics are not intentionally deceiving their prey. For example, indigenous Australians who dress up as and imitate kangaroos when hunting would not be considered aggressive mimics, nor would a human angler. Treated separately is molecular mimicry, which also shares some similarity; for instance a virus may mimic the molecular properties of its host, allowing it access to its cells. Aggressive mimicry is opposite in principle to defensive mimicry, where the mimic generally benefits from being treated as harmful. The mimic may resemble its own prey, or some other organism which is beneficial or at least not harmful to the prey. The model, i.e. the organism being 'imitated', may experience increased or reduced fitness, or may not be affected at all by the relationship. On the other hand, the signal receiver inevitably suffers from being tricked, as is the case in most mimicry complexes. Aggressive mimicry often involves the predator employing signals which draw its potential prey towards it, a strategy which allows predators to simply sit and wait for prey to come to them. The promise of food or sex are most commonly used as lures. However, this need not be the case; as long as the predator's true identity is concealed, it may be able to approach prey more easily than would otherwise be the case. In terms of species involved, systems may be composed of two or three species; in two-species systems the signal receiver, or "dupe", is the model. In terms of the visual dimension, distinction between aggressive mimicry and camouflage is not always clear. Authors such as Wickler〔Wickler, W. 1968. Mimicry in plants and animals. McGraw-Hill, New York〕 have emphasized the significance of the signal to its receiver as delineating mimicry from camouflage. However, it is not easy to assess how 'significant' a signal may be for the dupe, and the distinction between the two can thus be rather fuzzy. Mixed signals may also be employed. Aggressive mimics often have a specific part of the body sending a deceptive signal, with the rest being hidden or camouflaged. ==Comparison with other forms of mimicry== Mimicry that is aggressive stands in semantic contrast with ''defensive mimicry'', forms of mimicry where it is the ''prey'' that acts as a mimic, with predators being duped. Defensive mimicry includes the well-known Batesian and Müllerian forms of mimicry, where the mimic shares outward characteristics with an aposematic or harmful model. In Batesian mimicry, the mimic is modeled on a dangerous (usually unpalatable) species, while in Müllerian mimicry both species are harmful, and act as comimics, converging on a common set of signals and sharing the burden of 'educating' their predators. Also included in defensive mimicry is the lesser known Mertensian mimicry, where the mimic is ''more'' harmful than the model, and Vavilovian mimicry, where weeds come to mimic crops through unintentional artificial selection. In defensive mimicry, the mimic benefits by avoiding a harmful interaction with another organism that would be more likely to take place without the deceptive signals employed. Harmful interactions might involve being eaten, or pulled out of the ground as a weed. In contrast, the aggressive mimic benefits from an interaction that would be less likely to take place without the deception, at the expense of its target. However, it is important to note that there are other forms of mimicry that are described by the previous sentence, which are ''not'' aggressive mimicry—flowers exploiting a pollinator with deceptive signals, for example. There is no analogous word that encompasses all such cases of mimicry, however; Georges Pasteur, 1982 provides a review of classification of types of mimicry. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「aggressive mimicry」の詳細全文を読む スポンサード リンク
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