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Ch. 1: An Ark of Toads Teacher Sheet

Ch. 1: An Ark of Toads Teacher Sheet

Introduction

The "An Ark of Toads" chapter explores the story of the attempt to save a rare spray toad in face of an economical/political challenge. This chapter explores the value of animal life and the cost of trying to save it. This teacher sheet provides background information and answers for the questions on the student sheet. 


There are many key terms introduced in this chapter that students may not be familiar with. If there are any terms missing on this sheet that you think the students should know, please add them. Use the resources provided to familiarize yourself with this chapter and the concepts presented. The takeaway points of this chapter include:

  • The dilemma between saving a rare organism vs. providing electricity for a poor country. This brings up the idea of conservation as a “high class problem” in which millions were spent to try to save these toads that lived in this very specific microclimate (the spray of the waterfall was essential for their survival). The building of the hydro-powdered dam affected the waterfall spray and the toad population declined. A subset of the population was transferred to the Bronx zoo in an attempt at captive breeding. Issues with this are that the genetic fitness (diversity of the gene pool) declines and toads acquire adaptations to this new environment that may not be beneficial to their native environment. There are very few successful attempts at reintroducing captive species to the wild. The toads eventually became extinct due to disease.
  • The idea of intrinsic value is brought up in this chapter. This is the idea that all life has value regardless of its use to others. This idea questions the goal of conservation and what it means for us and does the organism need to be useful or provide some value to us to preserve and save it. One idea of why biodiversity is important is that the organism could be a potential pharmaceutical source or resource for us.

Key Terms

  • Conservation ecology – efforts to preserve nature and wildlife and prevent extinction; usually a compromise between nature and human activity
  • Endemic species – organisms that only exist in one geographical area
  • Microclimate – a mini climate within an area; can be the environment under a log or, in this case, the spray zone of a waterfall
  • Intrinsic value – an organism has value of its own regardless of others
  • Extinction – death of the last of a species
  • Wildlife corridors – land that joins fragmented pieces to help faciliate movement of organisms from one area to another
  • Captive breeding – population is removed from the wild and bred in a controlled environment such as a zoo
  • Genetic fitness – measure of reproductive success
  • Natural selection – process that contributes to evolution; works on existing traits in a population; genetic diversity is necessary for this to occur
  • Biodiversity – variation at different levels such as genetic, species, and ecosystem 

Questions

1. In your own words explain the dilemma in this chapter. 
The building of the hydro-powdered dam was underway and the area had to be examined by scientists to see what impact it would have on the surrounding environment. A population of spray toads were found in the spray zone of the waterfall, which created a very specific microclimate. Efforts went into preserving this microclimate while proceeding with the hydro-powered dam. Efforts were not successful and a subset of the population was transferred to the Bronx zoo in an attempt at captive breeding. The toads were eventually reintroduced back into their environment. However, disease hit and they became extinct. This brings up an ethical issue of whether or not species conservation should be put above the needs of people (i.e., saving a rare organism vs. providing electricity for a poor country).

2. What was the most interesting thing you discovered in this chapter?
Answers will vary. Encourage your students to explain their answers.

3. What was confusing?
Answers will vary. Encourage your students to explain their answers.

4. In your own words, explain what value species have to you. How do you think the human population benefits from biodiversity?
Answers will vary. Many students may say that species are just cool. Some possible answers for how we benefit from biodiversity are that it adds genetic diversity, could be undiscovered medicinal purposes, and good for our ecosystem.

5. Do you agree with the concept of intrinsic value? Explain.
Students will have defined intrinsic value above. This means that all life as value regardless of its value to others. Answers may vary for this and many students may not have thought of this idea before. The book also talks more about this concept.

6. Explain what is meant by a microclimate. What was the toad’s microclimate like?
A microclimate is a smaller climate within a climate (i.e., the climate under a fallen log in a forest). The toads lived in the spray zone of the waterfall, so their microclimate was very, very wet!

7. How is an animal’s fitness measured?
Fitness is measured by the reproduction of an animal. The more it can reproduce, the more likely it will pass on its genetic information to future populations.

8. What may be some issues when returning captive animals to the wild?
If only a subset of a population is in captive breeding, then their offspring will not be very genetically diverse. This can lead to decreased genetic fitness and adaptations to that captive environment so when introduced back into the wild they may not be fit enough to survive. 

9. What was the likely final cause of the toad’s extinction in the wild?
They caught a disease that wiped out the population. There were many speculations of how that fungal disease made it to their habitat.

10. Research any additional information out there on these spray toads that was not mentioned in this book.
Answers will vary on this. Encourage them to look up pictures or anything else that will add to their understanding about these toads.

This teacher sheet is a part of the Resurrection Science lesson.

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