Metaphors can be powerful teaching tools, leading us to an understanding of new concepts by connecting them to ideas we have already grasped. As with any tool, choosing the right one is important. A metaphor that builds on a familiar, evocative image but fails to capture essential details of the new concept can give a false impression of learning. It’s like using a wrench that’s too big. You turn and turn and feel like you are doing work, but at the other end nothing happens because the wrench hasn’t engaged.
Some ideas in science are learned readily, because they match our intuition of our how the world works, built from common experiences. Gravity makes sense because we’ve all jumped up and then come back down. The flow of electricity is easy to observe as lightning or a spark of static. Deciding if a baby has her mother’s eyes or her father’s smile introduces us to inherited traits.
Learning evolutionary biology presents a bigger challenge . . .