Mimicry

by

Leena Lindström, Johanna Mappes

• LAST REVIEWED: 10 March 2015
• LAST MODIFIED: 10 March 2015
• DOI: 10.1093/obo/9780199941728-0062

Introduction

The visual resemblance of vivid color patterns among various species is a celebrated example of adaptation to avoid predators. You might have misidentified a hoverfly for a wasp or be amazed to notify that not all king snakes that look alike are poisonous. Still today after 200 years of research, mimetic resemblance is a classic example of adaptation produced by natural selection but also used for unraveling speciation mechanism and understanding the genomics underlying phenotypic variation. Protective mimicry has classically been considered to have at least three players: the model, the mimic, and the predator/dupe. For the predator it is beneficial to avoid the model, because it is a warningly colored (i.e., aposematic) species, signaling its secondary defenses (e.g., toxicity, unprofitability as prey) with often colorful signals. The efficacy of warning signals is based on predator learning, generalization, and memory; therefore, these signals are often quite conspicuous, which makes the detection of the prey easy for predators. The predator learns to associate the warning signals with the secondary defenses and therefore the mimic by sharing the same warning signals of the model is avoided along the model. Mimetic resemblance has been considered to be either parasitic (Batesian) or collaborative (Müllerian). In Batesian mimicry, prey (i.e., mimics) without the secondary defenses are using warning signals for the deception of predators. In Müllerian mimicry, in turn, the relationship of two or more defended prey (i.e., co-mimics) is considered to be mutually beneficial as by sharing the same warning signals the predator does not need to learn to avoid many signals simultaneously. The main difference in these two extremes of mimetic resemblance is the benefits to each player. In Müllerian mimicry the mimetic resemblance can be considered to be beneficial to all three players, whereas in Batesian mimicry the mimics are the only true beneficiaries. This leads to different evolutionary dynamics within each system. Mimicry is thus a complex phenomenon, and in order to understand protective mimicry one needs to approach this phenomenon from multiple angles simultaneously.

General Overviews

In order to appreciate the mimetic resemblance, readers are advised to start from the great natural history books written on animal coloration. This will get readers both fascinated with and accustomed to mimicry literature. Poulton 1890 and Cott 1940 give an ample number of examples of mimetic similarities in nature. Most of the mimicry literature focuses on the mimetic color pattern similarity, but similarities among species can be found within other modalities such as olfactory mimicry. To fully understand the process of evolution on mimetic systems Brower 1988 stresses that it is essential to understand this phenomenon from multiple angles simultaneously. A general introduction that takes the phenomenon as whole can be found in Joron 2003; Ruxton, et al. 2004; and Sherrat 2008. As protective mimicry is an adaptation against predation, one needs to understand first how the process of predation creates a selective pressure on its prey as described by Endler 1993. As the benefit of mimetic resemblance is based on aposematism, it is also important to understand the special relationship between aposematic prey and their potential predators, which are topics covered by Rowe 2001 and Ruxton, et al. 2004. As mimicry itself can be classified as similarity among different parties, in addition to the protective mimicry, other types of mimicry also exist that Pasteur 1982 nicely lists. Mimicry in plants is most commonly associated in gaining pollination benefits, and the plants therefore resemble some reproductive structures of those insects that pollinate them. Barrett 1987 is an early review of plant mimicry that includes, for example, orchids having both visual and olfactory mimics of a female wasp to lure males to both deposit and pick up pollen.

• Barrett, Spencer C. H. 1987. Mimicry in plants. Scientific American 255:76–83.

  DOI: 10.1038/scientificamerican0987-76

  Describes mimicry in plants with many examples and suggests that it involves many ecological interactions. Mimicry in plants can be seen as a diverse phenomenon ranging from deception (insect pollinators) to avoidance of predators (humans on weed species).

• Brower, Lincoln P., guest ed. 1988. Mimicry and the evolutionary process. Special issue: American Naturalist 131:S1–S121.

  Based on a symposium organized by Lincoln P. Brower. The symposium was dedicated to E. B. Ford (b. 1901–d. 1988) for his contributions in understanding the ecological genetics of mimicry. The whole supplement contains six great papers associated with the evolutionary process of mimicry.

• Cott, Hugh B. 1940. Adaptive coloration in animals. London: Menthuen.

  This is a great natural history perspective on protective coloration in animals with the mechanistic explanations.

• Endler, John. A. 1993. Interactions between predators and prey. In Behavioural ecology: An evolutionary Approach. 3d ed. Edited by John R. Krebs and Nick B. Davies, 169–196. Cambridge, UK: Blackwell Science.

  Excellent description of how predators and prey interact. Describes predation as a sequence of events and gives the different mechanisms by which prey have developed defenses to avoid predation. Other researchers have largely adapted this classification. One of the easiest reviews to start with for exploring the mimicry phenomenon.

• Joron, Mathieu. 2003. Mimicry. In Encyclopedia of insects. 2d ed. Edited by Ring T. Cardé and Vincent H. Resh, 633–643. New York: Academic.

  This is a short and balanced introduction of the protective mimetic resemblance in both Batesian and Müllerian mimicry with explanation of the multiple selection mechanisms that generate mimicry. Also incorporates genetic information.

• Pasteur, G. 1982. A classificatory review of mimicry systems. Annual Review of Ecology and Systematics 13:169–199.

  DOI: 10.1146/annurev.es.13.110182.001125

  Defines several different mimetic similarities in addition to Batesian and Müllerian mimicries.

• Poulton, Edward B. 1890. The colours of animals, their meaning and use: Especially considered in the case of insects. 2d ed. London: Paul, Trench, Trübner.

  DOI: 10.5962/bhl.title.69899

  Classic book with classification of the all known phenomenon of animal coloration accompanied with many natural examples.

• Rowe, Candy, guest ed. 2001. Warning signals and mimicry. Dordrecht, Germany: Kluwer Academic.

  This is a collection of papers on various aspects of animal coloration and mimicry that was originally published in Evolutionary Ecology and based on a workshop “Aposematism: Past, Present and Future.” The workshop was held in spring of 2000 in Jyväskylä, Finland.

• Ruxton, Graeme D., Thomas N. Sherratt, and Mike P. Speed. 2004. Avoiding attack: The evolutionary ecology of crypsis, warning signals and mimicry. Oxford: Oxford Univ. Press.

  DOI: 10.1093/acprof:oso/9780198528609.001.0001

  This book summons up the current experimental and theoretical literature on the topic, thus giving an easy entry point for approaching the topic. Second edition is expected to be published in 2015.

• Sherrat, Thomas N. 2008. The evolution of Müllerian mimicry. Naturwissenschaften 95:681–695.

  DOI: 10.1007/s00114-008-0403-y

  Reviews the literature, assumptions, and data of Müllerian mimicry from Fritz Müller’s original formulation up to date.