Animated by artist Sarah Pedro, “The Science of Symmetry” is a TED-Ed talk given by educator Colm Kelleher explaining the precise scientific and mathematical definition of symmetry and why the concept is import to life as we know it.
The thing that unites bilaterally symmetrical animals is that their bodies are designed around movement. If you want to pick one direction and move that way, it helps to have a front end, where you can group your sensory organs — your eyes, ears and nose.