Reports of the National Center for Science Education

Quantifying the Importance of Evolution

Recently a concerned parent asked NCSE for advice because her child's science teacher planned to skip the textbook chapter on evolution in order to avoid conflict with a creationist student who was very vocal about his views. Besides offering the teacher support for teaching evolution, this parent wanted to provide the teacher with solid information about how to teach evolution well, and the reasons it is important to teach evolution.

As many readers of RNCSE know, leading scientific and educational organizations have all developed science curriculum guidelines that strongly emphasize the importance of evolution as a unifying principle. For example, the National Science Education Standards released by the National Academy of Science in 1996 list five "Unifying Concepts and Processes" underlying all scientific disciplines:

Systems, order, and organization
Evidence, models, and explanation
Change, constancy, and measurement
Evolution and equilibrium (italics added)
Form and Function
(National Academy of Science, 1996)

Standards developed by the National Science Teachers Association and the American Academy for the Advancement of Science emphasize evolution just as strongly, and all these documents have helped tremendously with efforts to assure that evolution is included in state science guidelines.

Still, for a classroom teacher who is being pressed not to teach evolution, it may be necessary to give a very concrete, practical answer to the question, "What harm is done if my child doesn't study evolution?" And the answer is, "S/he can't possibly score well on the College Board biology exams," (also known as "subject SAT tests".)

In describing each of the tests in biology, College Board literature not only states the importance of evolution, but quantifies it. It says of the Biology Subject Test, "Skills Needed ... Ability to recall and understand the major concepts of biology and to apply the principles learned to solve specific problems in biology," and reports that 10% of the questions cover "Classical Genetics" and 11% cover "Evolution and Diversity." For the Biology E/M (Evolutionary/Molecular) Subject Test, which was first offered in 1997, each student takes a number of core questions, then elects to take either the "evolutionary" or molecular" portion of the test. The College Board states that, "[The] Purpose [is] To assess the student's understanding of core topics in general biology. Special emphasis is placed on either ecology or molecular biology, with recognition that evolution is inherent in both" (emphasis added). The specialized questions comprise 25% of the test, and core questions devoted to biology comprise another 11%.

The Advanced Placement test, which is based on "college curriculum surveys of introductory biology courses for biology majors," devotes 25% of questions to "Heredity and Evolution." The Board says of one other biology test, "The Subject Examination in General Biology covers material usually taught in a one-year biology course at the college level." The proportion of the test devoted to "Population Biology" makes up 33% of a student's score, and includes questions on "Principles of evolution: History of evolutionary concepts, Lamarckian and Darwinian theories; Adaptive radiation; Major features of plant and animal evolution; Concepts of homology and analogy; Convergence, extinction, balanced polymorphism, genetic drift ; Classification of living organisms; Evolutionary history of humans." Related concepts - about Mendelian and modern genetics, for example - are included in other portions of the test. (All the foregoing quotations are excerpted from test descriptions at the College Board Online web site at

Even students who don't intend to major in science in college must respect the needs of classmates who will take qualifying exams in which roughly 20%-36% of the questions require an understanding of evolution. But that is not the only concern the emphasis on evolution in these examinations also reflects the fact that an understanding of evolution is a crucial element of scientific literacy. The "harm" in excluding evolution is the denial of an education that includes a fundamental scientific concept - and that can't be quantified. What price ignorance?

By Molleen Matsumura, NCSE Network Project Director
This version might differ slightly from the print publication.