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Grades 9-12
Have you ever watched a tadpole morph into a frog? National Geographic Emerging Explorer Tyrone Hayes says that, as a child, watching this animal—an animal that is really two animals—led him to his career in biology and herpetology. He didn't know it at the time, but watching tadpoles metamorphose into frogs may help us find causes of—and maybe even cures for—cancer. Hayes uses a combination of laboratory and field study on frogs to study their developmental changes related to chemical contamination of water. In addition to this exciting area of research, by studying how low-level chemical contaminants in water affect the development of frogs, Hayes hopes to spur better water conservation and environmental control efforts worldwide.
Connections to the Curriculum:
Geography, social studies, science
Connections to the National Geography Standards:
Standard 6: "How culture and experience influence people's perceptions of places and regions"
Standard 14: "How human actions modify the physical environment"
Standard 18: "How to apply geography to interpret the present and plan for the future"
Two to three hours

Materials Required:
  • Computer with Internet access
  • Writing paper and pens
Students will
  • learn about the life and work of Tyrone Hayes;
  • explain how Hayes's cultural and life experiences influenced his career choice and locations of study; and
  • explain how studying animals' development may provide insight into environmental hazards for humans.
Geographic Skills:

Acquiring Geographic Information
Organizing Geographic Information
Answering Geographic Questions
Analyzing Geographic Information

S u g g e s t e d   P r o c e d u r e
Ask students if they have ever considered how much like frogs they are. Ask for volunteers to offer examples of how that might be true. Take a few examples, and then tell students that they will be learning about a scientist, Tyrone Hayes, who is using the study of frogs to make significant contributions to humans' health and development.
Explain to students that we never know where new ideas and information can come from, and that they may be surprised how Hayes's childhood interest in frogs spurred a career that may be helping in the fight against cancer!

Activity 1:
Introduce students to Hayes by having them read a profile of his life and work .

Ask for students' reactions to the information they read about Hayes. How did Hayes become interested in studying frogs? Where has he done his fieldwork? How does he believe that studying frogs can help humans?

Have students visit the National Geographic magazine feature The Fragile World of Frogs and the Exploratorium online exhibit Frogs: Inside the lab and out in the field—A profile of frog researcher Dr. Tyrone Hayes to learn about how the world's frog populations are affected by the environment, and the ways in which those frog populations can be seen as alarm systems for human health.

Students should use the available resources to answer these questions in writing, or by creating a small group oral report:

  1. What similarities are there between frogs and humans?
  2. What are some reasons that frogs make good research subjects?
  3. Where has Hayes done field research? Why does he spend so much time in the field? Why not just work in a lab?
  4. Why are frogs good subjects to use when studying the potential effects of contaminants?
  5. What are the potential long-term benefits of Professor Hayes's research?
Activity 2:
Have students select one of three topics in which frog studies are helping to provide information—pesticide use, cancer, or cryopreservation—and conduct research using the provided resources along with their own research to learn about how frog studies are advancing science in these areas. Students should develop an opinion based on the information provided, and write a position paper about the issue:

Atrazine: Atrazine should or should not be banned

National Geographic News: Pesticides, Parasite May Cause Frog Deformities
National Geographic News: Hermaphrodite Frogs Caused By Popular Weed Killer?
Amphibian Conservation Alliance: FROGS.org—You Decide: Atrazine Ban
Earth Day Network: Water for Life—Pesticides
Wreaking Havoc with Life: Minute atrazine levels lead to hermaphroditic frogs, cancer
(PDF, Adobe Acrobat Reader required)

Cancer: Frogs should or should not be used to develop potential cures for cancer

Exploratorium: Frogs—Environmental Sentinels
Exploratorium: The Cancer Connection
Earth Day Network: Toxics and Water

Cryopreservation: The FDA should or should not grant permission for cryopreservation trials on human organs

Exploratorium: Cold-blooded Solutions to Warm-blooded Problems
The Seattle Times: Looking to Frozen Frogs for Clues to Improve Human Medicine
Audubon: Ask Audubon (Scroll down to "How do frogs survive winter?")

Ask students to reflect on the possibility of using frog populations as detection devices for environmental contaminants. What are the implications, both positive and negative, for science and health? Suggest that students consider the consequences of raising frog populations specifically for this purpose (amphibian population would increase, thwarting the current decline, but the exposure of these new populations to the various scientific research tests could be detrimental to frogs in general).
Suggested Student Assessment:
Student papers should reflect a clear understanding of the information they have studied. While there is not necessarily one "right" answer for any of the issues, students should demonstrate their awareness of the importance of the studies.
Extending the Lesson:
Related Links: