Ever since the Scopes Monkey Trial -- and probably since Darwin's book itself -- the role of evolution in education has been hotly contested. Some feel that evolution has no place in public schools (and not just in the US!). Others feel that evolution is plain wrong. Yet another camp is staunchly for evolution and believes that to teach anything else is to fly in the face of science.
One of the more recent battles is taking place in Cobb County, Wisconsin, as outlined in the recent New York Times Article "Stickers Put in Evolution Text Are the Subject of a Federal Trial." The first paragraph of the article sums the argument:
A federal judge began hearing testimony on Monday about whether the Cobb County School District should be allowed to leave stickers in biology textbooks saying that evolution was "a theory, not a fact" and should be "approached with an open mind, studied carefully, and critically considered."
As later stated in the article, the use of these stickers, and the arguments of some parents, really come down to the critical definition of a scientific word also common in the vernacular realm: theory. The order of definitions at dictionary.com highlights the main controversy over the word.
If you'll note, the first definition clearly states that a theory is "a set of statements or principles devised to explain a group of facts or phenomena, especially one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena." (emphasis mine)
This flies in the face of the fourth definition, which says a theory is "abstract reasoning; speculation." However, it does go on to note that this is "a decision based on experience rather than theory," which indicates that this fourth meaning of the word theory is radically different than the first one.
The main problem with popular culture is that we use the word theory to describe what is more commonly known in science as a hypothesis. To quote from A Handbook of Biological Investigation, by Ambrose & Ambrose (6th ed, page 2):
"Much confusion has resulted from the inconsistent usage of scientific terminology. For example, in colloquial use, a "theory" refers to an untested speculation, or "guess," analogous to a "hypothesis" in scientific usage. However, in science a theory is much bigger than a hypothesis. A theory is a conceptual framework that explains a variety of phenomena and is supported by innumerable observations and experimental tests (for example, the theory of gravity, the theory of evolution, the theory of atoms, the theory of continental drift, etc.). A theory cannot be disproved by a single experiment, as can a hypothesis."
Really, in scientific theory, nothing ever becomes a fact. Well, data points can be fact. It is fact that I found no salamanders in my search transect last week. It is fact that there was 100% humidity in my search transect last week. However, it is not fact, nor even theory, that there were no salamanders in my search transect because there was 0% canopy cover over the area. That is a hypothesis; I am attempting to disprove the influence of other variables and isolate consistent results that vary only based on canopy cover. If I am able to do that, then I can continue to test my hypothesis in a variety of settings, times, and habitats until I can say that I've done enough testing that it's highly unlikely that my results could be disproven.
Science is the field of negation. Scientific "results" come from negating influences. In Ambrose and Ambrose, they discuss an experiment to discover why a college student's fern dies. Over many, many rounds of experimentation, this college student continually isolates and tests different variables to determine the effect each variable has on his test subject (the fern).
That, ladies and gentlemen, is the way we do science. Scientists don't really "prove" things, despite our colloquial slip-ups and the blurbs advertising the daily news broadcast. Scientists disprove the effect of other variables. Scientists test influences. And, eventually, after a plethora of hypotheses, observation, testing, and more testing, we arrive at a theory. It's safe to assume that theories are fairly solid. After all, even gravity is only a theory, even though we have the opportunity to test gravity on a daily basis. If we're going to disregard evolution on the basis of it being "only" a theory, then I want to see some floating in those classrooms. Go on, float. Disprove all our theories. Then I'll listen.