Mimicry: An Example Of Adaptation
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Studying Living Organisms

Mimicry: An Example Of Adaptation

Gail Corey and William Sumner
Woodrow Wilson Biology Institute
1995

Target age or
ability group:
Introductory high school biology.
Class time
required:
15-30 minutes.

Introduction

Mimicry is one of several anti-predatory devices found in nature. Specifically it is a situation in which one species called the mimic resembles in color, form, and/or behavior another species called the model. In so doing, the mimic acquires some survival advantage.

There are 2 basic forms of mimicry:

1. Batesian - the mimic (palatable) resembles the model (unpalatable) and only the mimic benefits.

2. Mullerian - both the mimic and the model are unpalatable and both benefit.

Batesian mimicry is most effective when the mimic is rare and its emergence follows that of the model. In Mullerian mimicry as density increases so does the adaptive value. Since mimicry provides potential survival value, the mimic with an adaptation that increases the likelihood of surviving is selected. Natural selection of these favorable variations has led to the coevolution of many species. The distinction among camouflage (cryptic coloration), warning coloration, and mimicry is not always clear. Mimicry, as opposed to camouflage and warning coloration, is specifically the resemblance between two organisms. The same techniques of deception are sometimes utilized in all three anti-predatory devices. These include variations in color, pattern, and structure.

Student Objectives

1. To be able to explain the relationship between adaptation and ability for survival and reproduction.

2. To be able to give examples of a series of adaptations that would support the idea that evolution is a series of minor changes.

3. To be able to compare and contrast adaptations involving camouflage, warning coloration, and mimicry.

4 .To be able to understand and explain the two basic types of mimicry adaptation: Batesian and Mullerian.

Vocabulary
Mimicry, evolution, natural selection, adaptation, camouflage, warning coloration


Examples of Mimicry

Visual

1. monarch and viceroy butterflies (see Fig. 48.13 in Curtis, Barnes. 1989. Biology, 5th Ed.)

2. yellow jacket and sand wasp (see Fig. 48.15 in above reference)

3. syrphid fly and honey bee (see Fig. 48.11 in Campbell. 1987. Biology)

4. coral snake and colubrid snake (see plates I and II in Pough. Mimicry of Vertebrates; pp. 67-95)

5. cuckoo and various host birds (an example of egg mimicry)

6. red-backed salamander and red salamander

7. poison-fang blenny and Ecsenius blenny

8. gold-of-pleasure plant and the flax plant

9. mantid (insectivorous) and orchid (see Fig. 8 in Wickler. 1968. Mimicry in Plants and Animals)

10. ophrys (orchids) and female of some species

11. pipe-vine swallowtail butterfly and spice-bush swallowtail

12. caterpillars and catkins (see Geographica section of Oct. 89 National Geographic)

Odor

13. caterpillar and Myrmica ant (see Earth Almanac section of Dec. 91 National Geographic)

14. spider and red ant of Florida

Artificial Selection

Student Activity

This activity is designed to simulate mimicry in nature. Various assorted materials can be used to represent prey. Students represent predators. Materials used to represent prey should be edible and should come in varying colors. Choose two colors that most closely match to represent the mimic and the model. Select one of these colors and alter its taste by placing in an unpleasant substance such as Tabasco or concentrated lemon extract. This one will represent the model and the closely matching color not treated with an unpleasant substance will represent the mimic.

Suggested Materials

Fruit Loops/Cheerios(whole grain)/ Gummy Savers (120-150 assorted colors/class of 20) Tabasco/Concentrated lemon juice/ Worcestershire sauce

Preparation and Procedure

1. Teacher needs to prepare the unpleasant materials sufficiently in advance to allow materials to become thoroughly dry. (If using cereal, place other pieces in water briefly and allow to dry).

2. On day of activity spread 120-150 of materials chosen on clean tray or table top in random fashion. Record number of each different colored "prey" at beginning of activity.

3. Have each student come to materials and select any one of their choice and return with it to their seat.

4. After all students have returned to their seats, have them eat the piece selected. (Caution students to not reveal any aspect of what they experience.)

5. Repeat steps three and four an additional four or five rounds.

6. Record colors and numbers of different "prey" remaining.

Follow-up Discussion

1. What colors remain and in what proportion? Explain these results.

2. How might this exercise relate to organisms in nature?

3. What method of evading predators does this activity illustrate?

4. Give actual examples from nature that this activity simulated.

Further Reading

Brower, L.P. (ed.). 1980. Mimicry and the Evolutionary Process, University of Chicago Press.

deBeer, G. 1978. Adaptation, #22 Carolina Biology Readers.

Owen, D. 1980. Camouflage and Mimicry, University of Chicago Press.

Sisson, R. "Deception: Formula for Survival," National Geographic, March 1980:394-415.

Wickler, W. 1968. Mimicry in Plants and Animals, McGraw-Hill, New York.

Note: These references have illustrations of many of the examples listed.

On to Coevolution: A Simulation
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