Semeniuk’s article discusses Paul Hebert’s dream to genetically index every multicellular species on Earth, while Geoffrey York’s August 11 article “South African president laughs off uproar over killing of Cecil the lion” deals with the practice of lion hunting and the growing opposition to this activity.
Appropriate Subject Area(s):
Environmental studies, biology, world issues
Key Questions to Explore:
- What is the extent of species extinction?
- How widespread is the problem?
- What are its causes?
- What could or should be done?
DNA barcoding, biodiversity, taxonomy
Access to the Internet
Introduction to lesson and task:
Whenever a discussion about our environment occurs, the topic of climate change is invariably raised. The result is a myriad differing opinions and ideas concerning the nature, urgency and causes of this phenomenon. There are, however, other aspects that receive relatively less attention unless they are seen in terms of climate change. For example, the widespread disappearance of entire species is occurring at an alarming rate but the extent of this problem is often not readily appreciated because attention is usually directed solely to high-profile, endangered species such as the polar bear.
It is estimated that there are between 10 million and 20 million multicellular species on Earth. At the current rate of extinction, however, one third of them could be gone by the turn of the century. How significant is this to humans? What will be the impact of this continued high rate of extinction? To what degree is human activity responsible for this situation? What could and should be done? Are we prepared to do it? These are some of the questions that this lesson will pose for the students and, in doing so, heighten their awareness of the situation and increase their understanding of actions that could and should be taken.
Action (lesson plan and task):
- Ask the students to identify what comes to mind when they hear the term “climate change.”
- Make a list of the topics they identify.
- If species extinction is not on the list, identify it for them as a topic that needs to be considered. If it is on the list, indicate to them that it is the topic which will be the focus of the lesson.
- Have the students estimate how many multicellular species exist on Earth (between 10 and 20 million).
- Ask them to suggest whether they believe that these species are relatively secure or if they are concerned that they are threatened.
- Focusing on the concern about the threat to these species, ask the students to explain why they believe they are threatened.
- With these discussions as background, give the students copies of the two articles and allow them time to read them.
- Once this has been done, answer any questions of clarification that they may have.
- At this point, put the students into groups of five or six and give the groups the following questions to address:
- How significant do you believe the rapid disappearance of the Earth’s species is? (In response to this question you should consider three things: how significant do you believe it to be? How urgent do you believe it to be that we address it? What is the likelihood that the problem will grow if we do not do anything?)
- To what degree do you believe human activity is responsible for this alarming rate of extinction? Be specific in terms of the types of human activity that you consider.
- Address the following three-part question as a response to question 2:
- What could be done?
- What should be done?
- Are we prepared to do it?
- Give the students the remainder of the period to complete their tasks and tell them that their group reports should be ready for the next class.
Consolidation of Learning:
- Begin the second period of the lesson by allowing the groups a couple of minutes to organize their reports and then have the groups, in turn, report to the class.
- The students will demonstrate an awareness of the rapid extinction of species which is occurring.
- The students will demonstrate knowledge of the causes of the extinctions.
- The students will demonstrate knowledge of some of the actions that could be taken to address the problem.
- Once the group reports have been given, conduct a plenary class discussion during which the students can talk about the groups’ answers and offer any other suggestions or comments about this topic.
- As a follow-up homework assignment, have the students choose one threatened species and research the reasons for the threat and what might be done to address it.