A Mini-Lesson

Theory, Theory
Who's got the theory?

Michael L. Kimmel
ENSI 1991

Nature of Science

 SYNOPSIS

 CONCEPTS

1. There are different ideas about the origin of life.

2. Science deals only with natural explanations.

3. "Theory" has different meanings in science and casual conversation.

4. Human values and personal biases can deeply influence science (its terminology, the questions asked, and the criteria used for choosing among different ideas).

5. The scientific view of the origin of life on earth is that it did not involve supernatural forces.

 MATERIALS

Student handouts (see below)

References used to prepare features of each "theory"

Key to "theory" sources and approximate age

 STUDENT HANDOUTS

(see end of lesson for the formatted handouts).

Sets of 5 different "theories": scenarios for the origin of diverse life, enough so that each student gets one theory to analyze.

Worksheet with tasks and questions for individual evaluation of a "theory"

Worksheet with tasks and questions for group comparison of 5 "theories"

 TEACHING STRATEGY

CAUTION:
Do NOT reveal the authors or dates of the "theories" until AFTER the class discussion! To do so may bias the results.

THEORY - HYPOTHESIS - GUESS?
Before or during this lesson, be sure that your students are aware of the proper distinction between theory, hypothesis, and a hunch or guess. If this was studied earlier, use this opportunity for review by asking what the different scenarios presented would be properly called: theories, hypotheses, or something else [depends; see under "Objections" below]. If not studied earlier, it would be good at some point during this lesson to discuss the proper and inappropriate usages of these terms. They are defined nicely on site by Martin Nickels in his paper on THE NATURE OF MODERN SCIENCE & SCIENTIFIC KNOWLEDGE: Scroll down to part IV of the paper, where these terms are defined.
It should be emphasized that the word "theory" as used in science should NEVER be used for any non-scientific explanation, e.g. a religious belief, or in reference to a casual hunch or guess, as in "it's only a theory" (even though this is, unfortunately, the common colloquial meaning). Also, because a hypothesis may, after some indefinite degree of confirmation, rise to the level of "theory" (or part of a theory), references to a hypothesis as a "theory" should be presented with qualifying quotation marks.

CONTEXT:
This activity can be used as 1) an opener, or early in your unit on the nature of science, or 2) later in the unit, following your explanation of how "theory" should be defined in science.

In the first situation, after you have finished class discussion, you should point out that only one of the scenarios is technically a scientific theory ("Theory D"), for two main reasons: 1) no supernatural elements are included, and 2) it has been extensively tested and supported by the material evidence. "Theories" A, B, C, and E fail in both of those measures.

In the second situation, after class discussion of their evaluations, ask students to indicate which of the 5 scenarios is technically a scientific theory, and which are not, and the reason(s) for saying that (unless they have already pointed it out during discussion in the activity).

This could also be used as an opener to your introductory unit on evolution, as long as those clarifications are brought out and discussed as described above.

OBJECTIONS:
If there are objections to not considering "Theory E", be sure to point out that it might very well be correct, but it cannot be considered as a viable scientific alternative mainly because it doesn't lend itself to the basic rules of science, which mandate that all explanations must follow natural processes (not supernatural), and must be subject to testing and rejection. For these reasons, the only scenario which can be considered for lengthy treatment in a science class is "Theory D". And, because "Theory E" is a direct product of an established religion , it is actually illegal to include it as a scientific alternative in any public school science class in the USA, as concluded by the US Supreme Court.

PREPARATION:
1. Prepare enough copies of the 5 "theories" so that every fifth student gets the same "theory" to evaluate individually (could be a homework assignment). This would be 6 copies of each page for a class of 30.

2. Prepare copies of "Individual Theory Evaluation" forms, one per student. The version provided here is compressed, so there may be insufficient space for students to provide the requested information. You can simply have them do this on a separate sheet (using numbers for each item), or select, copy, and paste the text onto your word processor page, where you can insert sufficient lines or spaces for the desired responses.

3. Prepare copies of "Group theory Evaluation" forms, so there is one for every group of 5 students. Again, the version of provided here is compressed, which you can treat as for the "Individual Theory Evaluation" forms above.

PRESENTATION:
1. Distribute the 5 "theories" so that each student has one. Then handout the "Individual Theory Evaluation" forms, one per student. Allow some time for students to complete their evaluation forms (this would be a good homework assignment, if not finished in class). REMEMBER.... Do NOT disclose the authors or dates for the theories until AFTER discussion.

2. After individual evaluation is completed, have your class form groups of 5, so that all 5 "theories" are represented in each group, with at least one person with a completed "Individual Evaluation" for each "theory". Those who were absent, or who did not do the work, can be apportioned to different groups to sit in on the group discussions. If there are a few "extra" students (with their evaluations done), apportion them to existing teams (which will mean more than one evaluation has been done for one of the "theories", but that's ok). Try to balance out so all teams have only 5-6 students.

3. Each group must complete a "Group Theory Evaluation" form, using discussion and consensus. Teacher can provide the "age" of each "theory" when asked by a team (to answer question #3 on the evaluation form).

4. Finally, have each group report out to the entire class different aspects of their group evaluation, and engage in class-wide discussion. Teacher should make sure that the concepts (listed at beginning of this lesson) are accurately and clearly addressed during the discussion.

EXTENSIONS & VARIATIONS:
1. Additional scenarios could be added. For example, there are many interesting stories of creation in the great variety of primitive cultures in the world. One source for such stories, from which you could select one or two, can be obtained from NCSE. Just click to send an email asking for their flyer on "Origin Myths". Be sure to give your mailing address.

2. Dinosaurs are a constant fascination for kids, and the "asteroid impact" has become the popularly accepted explanation for their demise. Very few people realize that this is still hotly contested. For an interesting variation on the theme of this lesson, consider using dinosaur extinction as your focus. For an excellent discussion of the different hypotheses on the likely cause of this extinction, get Dinosaurs: The Science Behind the Stories, ed. by Judith Scotchmoor et al, published by the American Geological Institute (2002), and available online from http://www.agiweb.org/pubs/pubindex.html. Note especially chapter 12: Dinosaur Extinction: Changing Views (pages 99-106), where three hypotheses are presented and discussed. A very recent episode in this controversy was revealed in a Nature news article (10 April, 2003) in which new core samples from the reputed crater suggest an alternative explanation. Click here for a PDF copy of the brief article, along with a few review questions. For a more detailed presentation of this topic, go to our Theory Choices lesson.

RESOURCES:
The following were used as sources in compiling the information for this activity.
1. Biological Science: A Molecular Approach. BSCS Blue Version, D.C. Heath and Co. (5th & 6th editions)
2. Birx, H.J. Theories of Evolution. 1984. Charles C. Thomas Publisher.
3. Strahler, Arthur N. Science and Earth History: The Evolution/Creation Controversy. 1987. Prometheus Books.

THE "THEORIES" USED
Theory A: Aristotle, circa 350 B.C.
Theory B: Jean Lamarck, 1809
Theory C: Empedocles et al, circa 500 B.C.
Theory D: Charles Darwin, in his Origin of Species, 1859
Theory E: "Scientific Creationism" a la Morris and the Institute for Creation Research, circa 1960

 ATTRIBUTION

Some of the ideas in this lesson may have been adapted from earlier, unacknowledged sources without our knowledge. If the reader believes this to be the case, please let us know, and appropriate corrections will be made. Thanks.

1. Original Source: Michael Kimmel, ENSI '91

2. Reviewed by: M. Nickels, C. Nelson, J. Beard: 12/15/97

3. Edited / Revised for website by L. Flammer 3/01