The written testimony of Barbara ten Brink

Also, the proposed Position Statement of TSELA

August 25, 2003

TSELA, the Texas Science Education Leadership Association, representing over 400 science department chairpersons, coordinators, directors, and other leaders in science education, supports the following position statement on the Teaching of Evolution:

A scientific theory is not a guess, an approximation, or even a hypothesis but a "well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses" (National Academy of Sciences, 1998, p. 8). Examples of commonly accepted scientific theories include cell theory, which states that all living things are composed of cells, atomic theory, which states that all elements consist of unique building blocks termed atoms, and heliocentric theory which states that the earth and planets revolve around the sun. The status of each of these as theories in no way reduces their degree of acceptance within the scientific community or the general population. As with all scientific knowledge, theories can be refined and even replaced when new and more compelling evidence is discovered. While modern scientists constantly study, ponder and deliberate the mechanisms and pace of evolution, the preponderance of evidence supporting evolution by natural selection has established evolutionary theory as the central tenet of the biological sciences. The statement by noted biologist Theodosius Dobzhansky, 1973, "Nothing in biology makes sense except in the light of evolution." illustrates the central, unifying role of evolution in all sciences. As a result, science cannot be taught effectively and with scientific integrity without extensive classroom discussions and laboratory experiences that focus on evolution and its importance as a unifying element.

TSELA supports the teaching of evolution as required by the Texas Essential Knowledge and Skills, in the manner recommended by the National Science Education Standards, supported by the National Science Teachers Association, and as stipulated by the U.S. Supreme Court.

Texas Administrative Code (TAC), Title 19, Part II, Chapter 112.43 Biology. Texas Essential Knowledge and Skills for Science (1998):

§112.43. Biology. (b)  Introduction. (1)  …Students in Biology study a variety of topics that include: …biological evolution…

2. Scientific processes. The student uses scientific methods during field and laboratory investigations. The student is expected to: (A)  plan and implement investigative procedures including asking questions, formulating testable hypotheses, and selecting equipment and technology; (B)  collect data and make measurements with precision; (C)  organize, analyze, evaluate, make inferences, and predict trends from data; and (D)  communicate valid conclusions.
    
3. Scientific processes. The student uses critical thinking and scientific problem solving to make informed decisions. The student is expected to: (A)  analyze, review, and critique scientific explanations, including hypotheses and theories, as to their strengths and weaknesses using scientific evidence and information;
    
   ( 7)  Science concepts. The student knows the theory of biological evolution. The student is expected to: (A) identify evidence of change in species using fossils, DNA sequences, anatomical similarities, physiological similarities, and embryology; and (B)  illustrate the results of natural selection in speciation, diversity, phylogeny, adaptation, behavior, and extinction.

National Science Education Standards, National Research Council, National Academy Press, Washington, D.C., 1996:

• Millions of species of animals, plants, and microorganisms are alive today. Although different species might look dissimilar, the unity among organisms becomes apparent from an analysis of internal structures, the similarity of their chemical processes, and the evidence of common ancestry. (Page 158)
• Extinction of a species occurs when the environment changes and the adaptive characteristics of a species are insufficient to allow its survival. Fossils indicate that many organisms that lived long ago are extinct. Extinction of species is common; most of the species that have lived on the earth no longer exist. (Page 158)
• Biological evolution accounts for the diversity of species developed through gradual processes over many generations. Species acquire many of their unique characteristics through biological adaptation, which involves the selection of naturally occurring variations in populations. Biological adaptations include changes in structures, behaviors, or physiology that enhance survival and reproductive success in a particular environment. (Page 158)
• Species evolve over time. Evolution is the consequence of the interactions of (1) the potential for a species to increase its numbers, (2) the genetic variability of offspring due to mutation and recombination of genes, (3) a finite supply of the resources required for life, and (4) the ensuring selection by the environment of those offspring better able to survive and leave offspring. (Page 185)
• Natural selection and its evolutionary consequences provide a scientific explanation for the fossil record of ancient life forms, as well as for the striking molecular similarities observed among the diverse species of living organisms. (Page 185)
• The millions of different species of plants, animals, and microorganisms that live on earth today are related by descent from common ancestors. (Page 185)
• Biological classifications are based on how organisms are related. Organisms are classified into a hierarchy of groups and subgroups based on similarities, which reflect their evolutionary relationships. Species is the most fundamental unit of classification. (Page 185)

National Science Teachers Association, Position Statement, Adopted July 1997. NSTA recommends that:

• Science curricula and teachers should emphasize evolution in a manner commensurate with its importance as a unifying concept in science, and its overall explanatory power.
• Policy makers and administrators should not mandate policies requiring the teaching of creation science, or related concepts such as so-called "intelligent design," "abrupt appearance," and "arguments against evolution."
• Science teachers should not advocate any religious view about creation, nor advocate the converse: that there is no possibility of supernatural influence in bringing about the universe as we know it. Teachers should be nonjudgmental about the personal beliefs of students.
• Administrators should provide support to teachers as they design and implement curricula that emphasize evolution. This should include inservice education to assist teachers to teach evolution in a comprehensive and professional manner. Administrators also should support teachers against pressure to promote nonscientific views or to diminish or eliminate the study of evolution.
• Parental and community involvement in establishing the goals of science education and the curriculum development process should be encouraged and nurtured in our democratic society. However, the professional responsibility of science teachers and curriculum specialists to provide students with quality science education should not be bound by censorship, pseudoscience, inconsistencies, faulty scholarship, or unconstitutional mandates.
• Science textbooks shall emphasize evolution as a unifying concept. Publishers should not be required or volunteer to include disclaimers in textbooks concerning the nature and study of evolution.

Judicial decisions:

• Epperson v. Arkansas (1968): The U.S. Supreme Court struck down a 1928 Arkansas law prohibiting the teaching of evolution in state schools.
• McLean v. Arkansas (1982): The federal district court invalidated a state stature requiring equal classroom time for evolution and creationism.
• Edwards v. Aquillard (1987): The Supreme Court ruled against so-called "balanced treatment" of creationism and public schools. In this landmark case, the Court called the Louisiana equal-time stature "facially invalid as violative of the Establishment Clause of the First Amendment, because it lacks a clear secular purpose."
• The "Edwards Restriction" has been applied to science instruction in Illinois and California.

TSELA advocates presenting evolution as a theory supported by overwhelming data and facts and as an extensive explanation developed from well documented, reproducible sets of experimentally derived data from repeated observations of natural processes. Student understanding of the Nature of Science will be enhanced by providing:

• The study of evolution as a model of how scientific theories are modified and improved, as new empirical evidence is uncovered. Thus, science is a constantly self-correcting endeavor to understand nature and natural phenomena.
• Opportunities for students to be engaged in asking questions, proposing hypotheses, designing empirical models and conceptual frameworks, and other activities that characterize the scientific process.
• Opportunities for students to study evolution using a variety of print and electronic media that support the TEKS, TAKS, and the National Science Education Standards.

TSELA asserts that in our increasingly complex society, the need for a scientifically literate citizenry is inarguable. Teachers have a professional obligation to present the preponderance of evidence the support theories such as evolution or students will never learn to examine such evidence critically. Giving equal time to claims that don’t have equal scientific credibility distorts the evidence and misrepresents the state of the scientific field in question. The weight given to competing arguments and theories in a text or classroom instruction should reflect the quality and credibility of such evidence.