The teaching of science and the associated curricular formulation of the subjec t matter is a very complex undertaking. A satisfactory resolution of the problem requires a conscious effort toward multilevel teaching of the experiences and modes of understanding that have evolved in the natural sciences.
—Miro M. Todorivich, “Multilevel Teaching of the Natural Sciences,” The Philosophy of the Curriculum (Prometheus Books, 1975)
Although teaching at a small liberal arts college is rewarding, it presents some unique challenges. Courses in chemistry and biochemistry often befuddle students with the language of the disciplines. Teaching the dialects and subdialects of science in the context of complex theories is a demanding task. In one class of twenty to thirty undergraduates, precollege preparation varies from those who mastered Advanced Placement courses to others from impoverished rural or inner-city schools where up-to-date textbooks and lab experiences are limited. Add the international student, who usually has a stronger background in math and science than the U.S. student but whose English language skills may still be developing, and you have a vibrant and diverse group.
Within this student demographic also comes an array of religious histories. In fact, students at Denison University (where I teach) closely reflect the average religious identification of the population in the United States. For example, 15 to 20 percent of the students are atheist, agnostic, or unaffiliated. This also means that 80 percent of the students are spiritual in some way, the vast majority having been raised in formal religious traditions. A significant number of these students have been brought up to dismiss evolution and thus reject the main tenet of my discipline, biochemistry.
I cannot teach an introductory biochemistry class without referencing molecular evolution. But, I am not teaching evolution, complete with a thorough understanding of statistically predictable random mutations and natural selection. That topic demands an entire course. In teaching biochemistry, I make passing references to evolution, and in doing so give an incomplete and sometimes inaccurate explanation of it. The inaccuracy does not stem from any deficiency in my understanding but comes from the inexact yet colorful examples a teacher uses to convey a general picture of a complex topic.
Herein lies the problem: in using analogies and cartoonlike descriptions of evolution, I give evolution-denying students an easy escape from the facts, allowing them to dwell comfortably in their theologically based, thus misinformed, worldview.
The students’ diverse backgrounds make it difficult to interest the most—as well as the least—prepared while moving toward the initial course goals. Along this path of academic engagement, some shortcuts must be taken. I often find myself shading the truth about a topic, sacrificing a complete and nuanced understanding of a complex idea for a basic understanding of the core idea.
As a student of the sciences progresses through the curriculum, the subtleties become more evident. More complex and detailed descriptions replace summary and inexact explanations. For example, the first view of the atom is depicted as an electron orbiting around the nucleus. This picture explains the energy levels of electrons in terms of distance from the nucleus, and along with Lewis structures, provides a rudimentary understanding and predictive foundation for bonding. This is an inadequate picture, so we move to a statistical representation of electron orbitals—a solution to one of the most famous equations in chemistry/physics, the Schrödinger wave equation. However, even this more complex description falls short in fully describing bonding in molecules. Thus, molecular orbital theory is next used to addle the mind of the undergraduate.
In this evolving understanding of electrons, bonds, and molecules, teachers do not harm a student’s eventual understanding of the subtleties of chemical structure because they frequently remind the students that a more thorough understanding is being built. The process of understanding requires several semesters of different classes to get a more complete picture. However, if students stop this process before developing a full understanding, do we leave them with an improper—if not incorrect—picture? Probably, but in these cases the damage is minor, since a rudimentary understanding of bonding is preferable to none at all. But what about a situation in which there is no time to follow up a less than accurate or complete picture of the complex topic of evolution through natural selection? In this case, we run the risk of doing real harm to students’ understanding of evolutionary theory by providing incomplete descriptions of its subtleties and complexities.
In biochemistry, and to a lesser extent in chemistry, we often find ourselves referring to evolution as ancillary to a particular idea. We describe a trait in an organism as having evolved or evolution as having created a structure or molecule in order to address a challenge in nature. We use personal pronouns and action verbs to paint the picture. Of course, this type of anthropomorphic language is inaccurate, but it is a style of language we use to emphasize a topic for the sake of convenience. In using such language, we risk mischaracterizing the true and complex nature of evolution by natural selection. For those students who are not predisposed to learning about evolution or have an ingrained bias against the facts that explain evolution, we leave them with a false explanation of evolutionary determinism. Even the most articulate of evolutionary biologists sometimes resort to this inexact language. For example, Stephen Jay Gould once wrote of evolution: “Random variation may be the raw material of change, but natural selection builds good design by rejecting most variants while accepting and accumulating the few that improve adaptation to local environments” (The Panda’s Thumb, 1980). In fact, natural selection (and evolution by extension) does not have a predisposition to design anything, good or bad, in or out of the context of a “local environment.” Evolution by natural selection is, as Richard Dawkins has explained, “random variation followed by non-random survival.” To be fair to the memory of Professor Gould, he wrote many artistic treatises explaining evolution by natural selection in great detail: “A complete theory of evolution must acknowledge a balance between ‘external’ forces of environment imposing selection for local adaptation and ‘internal’ forces representing constraints of inheritance and development” (Hen’s Teeth and Horse’s Toes, 1983).
The teacher-scientist’s problem is not in lacking a full understanding of evolution. The problem is the language we choose in describing a “populist” version of evolution that ascribes animate decision-making capabilities to a purely physical process governed by the laws of thermodynamics. In essence, our language choices in describing evolution to the uninitiated can be interpreted as replacing the personal god with a guided, goal-oriented, evolutionary consciousness.
Evolution, like all aspects of the physical sciences, is a description of matter and the interaction of matter with energy (to the physical chemists out there, please forgive this oversimplified description). Evolution is a series of reactions and interactions occurring as a result of external energy input from the sun, which result in lower-energy and more metastable structures in the system in which the matter (atoms, molecules, cells, organisms) reside. The structures come about from a random process followin
g the statistical laws of thermodynamics. A structure is propagated through time if it has the necessary stability to continue to exist in the environment. If the structure does not have sufficient stability, then it will disassemble/reassemble before it can be propagated. Understanding evolution at this level requires a detailed, thorough, and subtle understanding of chemistry and biochemistry, a depth of knowledge that the majority of undergraduate students lack. So instead of presenting a nuanced and complete explanation of the evolutionary underpinnings of a biochemistry system, I resort to anthropomorphism: “The protease chymotrypsin has placed a series of hydrophobic amino acids at its binding site so it can recognize and specifically cleave peptides with hydrophobic amino acid side chains.” This is a reasonable, though inelegant, description of the biochemical points of importance, but it is a statement that completely misstates the true concept of molecular evolution.
However, the use of such language has its place. In lecturing to an undergraduate class or nonscientists, the use of technical jargon and excruciating scientific detail may not only bore the audience but may alienate the uninitiated. If a scientist can’t explain evolution in easily understandable terms, then distrust of the scientist arises and the overall distrust of science is elevated. Evolution becomes just a bunch of confusing statements that scientists tell people to take on “faith.” Once we get into the “faith as explanation” excuse, we are defeated in arguing with the “faithful” and evolution deniers.
Teachers in the sciences must walk an oratory tightrope. It is important, if not mandatory, for scientists to find the right venues in which—and the right rhetoric with which—to explain what we do behind the doors of our labs. If we don’t, then we become secretive people working against rather than for the greater good. In talking with the lay populace, we must use approachable language, which by necessity will often require an anthropomorphic storyline, especially when describing evolution. But we must be careful to not leave the false impression of evolution as a willful entity, being sure to qualify our anthropomorphic explanations whenever possible.
As teacher-scientists, we also must be aware of the risk of condescension. Everyone has the capacity to understand evolution, so we must be careful not to unintentionally denigrate the intelligence of our audiences and to remember the footnotes detailing the caveats of our explanations, so as not to give more ammunition to evolution deniers. How often have we heard the antievolutionist use such silly arguments as “the Second Law of Thermodynamics refutes the theory of evolution,” when with patience and clarity of accessible language choices we could explain the fallacy of the argument to any rational person? Neither the threat of fallacious arguments from the antievolutionist crowd nor our own intentional, inaccurate but worthwhile use of anthropomorphic language should keep us from reaching out to the student, the popular media—even the deniers—to continue to “preach the gospel” of evolution.