Dr. Evilution discusses and what teachers can do to make up for the it.
I like this idea: If you take your class on field trips to these places, design an exercise that charges your students with designing more interesting, evolution-based plaques. If you have a digital camera, you can take pictures of the existing plaques for use back in the classroom. Then get your students to send the ideas (slickly packaged) to the director of the place you visited. The students will enjoy being simultaneously engaged in both science and social change.