Lewis/Life - Teaching Techniques

Chapter 18 - Teaching Techniques

A. General Tips
This is a short, interesting chapter. Your students should not have any particular difficulties with the information presented here. Most of the chapter is written in an easy, narrative style.
Note the use of the Scientific Method in the opening vignette. You might wish to copy and distribute to your students the Overview of Chapter Objectives flowchart found at the beginning of this Instructor's Manual Chapter.
B. Possible Approaches to the Chapter
The material in this chapter -- actually in the whole unit -- lends itself well to the annotated outline. Such an outline could be assigned to be handed in before you lecture on the material. That way, the students would have a perception of the sequence of events under consideration and the lecture itself could be used to focus on a conceptual or developmental understanding of the information (rather than on a straight chronology).
C. Hints Related to Specific Chapter Topics
- I. Ask what is the difference between biological evolution (mentioned here) and chemical evolution (mentioned in the last chapter)? How are the two related?
  Notice the classic definition of species -- groups of organisms that do not normally interbreed. This interbreeding assumes viable, reproductively capable offspring. Someone may bring up problem areas like hybrid zones and abnormal conditions.
  Hybrid zones are the overlapping areas between the territories of two closely related species. For instance, dogs and wolves do not normally breed with each other, although they will if none of "their own kind" is around. The pups are viable and reproductively capable. This raises some interesting questions about the definitions of species. Meanwhile, mules do not constitute a true species because they cannot reproduce.
  The definition Lewis uses is the best definition around. But no definition of species is perfect.
- I.A. Relate the direct human intervention in the demise of the dodo to the information in Chapters 17 and 19.
- II. The information in this section is very straight forward. Ask the class how they would react to the statement: "We practice evolution."
- IV. The terms in bold face between pages 379 and 382 need to be emphasized. These are terms that students often think they know but they don't always have a clear understanding. This is particularly true of convergent evolution.
- VI.C. You cannot stress enough the problem of antibiotic resistance as brought on by people who absolutely insist they need an antibiotic for every ailment. Antibiotics do not work on viruses. You might wish to assign some outside research on how much more resistant individual bacterial species are today than they were in the past. You might also ask what we are going to do when we have no more antibiotics to treat infectious diseases with. Recall that antibiotics can also be toxic to humans and animals, particularly in the doses required to combat certain bacteria.