Science is a processed developed by man to provide a method for observing the universe, and to create a model describing how things work. In many cases the models produced are very good, but science can not be confused with fact. Science is a living field, and the models we are using to describe the universe continue to evolve. Just look at the model of an atom over the last few hundred years for a good example.
Traditionally throughout history Science has gone hand in hand with Philosophy. Aristotle's book on Physics was followed by his book on Metaphysics. Philosophy doesn't throw out a theory because it doesn't have a testable hypothesis, but attempts to combine all of human knowledge together to discover the truth behind reality. Biology class certainly isn't the best place to be teaching any idea that has an un-testable hypothesis, but there really isn't a better place in public schools to familiarize students with those ideas. Most public schools don't even have a philosophy curriculum, possibly because of its limited commercial applications.
