Iridescence as a form of coloration in animals

 Author: Jan Synder, Ed.D.

Area: Life Sciences 

 Grade Level: 5-8

Overview:

Whereas students will probably understand that color patterns in animals provide adaptive features that promote survival, they might not consider the mechanisms that exist to provide the color. Through guided efforts on the part of the teacher, students will probably realize that most colors in animals, like those objects most familiar to them (e.g. clothes, buildings, cars, etc), are a result of certain light waves being reflected from pigments. Although levels of understanding of pigments, and their capacity to absorb some light waves as they reflect others, will vary the basic concept should be readily understood. Indeed, most colors we see in nature are a result of this light-absorption/ reflection interaction with pigments.           

This activity allows students to investigate iridescence and its role in nature. Students are provided with web-based images of animals along with accompanying information. A question to explore might be, “Why does iridescence exist in nature when most coloration patterns are due to pigments in the outer surface layers of animals?” Students consider various animals examples, their environments and, in some cases, their behavior, in an effort to answer this question.

Standards:

National Standards

Content Standard C: Life Science           

•Structure and function in living systems           

•Diversity and adaptations of organisms 

Arizona State Standards

Strand 4: Life Science

Content 3: Populations of Organisms in an Ecosystem (Grade 7)           

PO 2. Explain how organisms obtain and use resources to develop and thrive in:                       

• niches                       

• predatory/prey relationships           

PO 3. Analyze the interactions of living organisms with their ecosystems:                       

• limiting factors

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