There may be something there that wasn’t there before.”
Beauty and the Beast
When we were talking about how cells work together to make your body, you might have noticed that there was a bit of a leap between your organ systems and you. After all, you are more than just a collection of organs, even if those organs are working together in complex ways. You have creative ideas, hopes and dreams, fears. You have a connection with the divine. In short, you have a soul, which is amazing and wonderful but not something that we can study in biology since it is not a part of the physical world.
But even for those creatures without souls, there is something more there than just a bunch of organs. Take a pet cat, for example. These creatures have likes and dislikes; they can be friendly or grouchy or skittish. A cat is not just lungs, a brain, a spleen, and the other organs. In short, there is something there that wasn’t there before.
In science, we call that “something” an emergent property – properties that appear unexpectedly out of complex systems, seemingly of their own accord. In such systems, you see various parts (such as lakes, clouds, and rain in the water cycle system) interact with each other and with the wider world to achieve a broader outcome (the movement of water through the environment). Sometimes in those systems, properties appear which are unpredictable from looking at each of the parts (such as the climate…well part of it – talk about a complex system). Take, as a biology example, an oak tree: you can predict that it will have leaves of a certain shape, a wide canopy, and strong roots, but you cannot predict where exactly a branch will grow or when a root will be forced to go around a rock. The actual shape of the tree is an emergent property of the oak tree system. Similarly, a particular cat’s personality is an emergent property of that particular complex cat system.
I know that it seems strange to think of an animal, or even a tree, as a “system” – a concept usually reserved for business or manufacturing. It is not meant to degrade the creatures but rather to be a way to talk about how parts of something interact with each other and with the outside world. Most systems that you will see in science will seem less strange, such as the water cycle or even ecosystems, but the “system” way of looking at everything in science, including creatures, can help you understand how the world works and where those important emergent properties are appearing.