The biological importance of memory

It is not brains that make memories; it is people, who use their brains to do so. And animals, non-human animals, also make memories, and can learn and change their behaviour as a result of experience. Even some animals without much in the way of brains at all, just rather basic nervous systems, can do it. What this points to is the tremendous importance that the capacity to learn and remember has for the survival of animals. Plants do not need nervous systems, because all they have to do is to stand around with their arms – or branches – spread wide so that their leaves can catch the sun and photosynthesize. But animals which live on plants, and even more so animals which live on other animals, have to use their wits to find and capture their prey, and to avoid being eaten in their turn at least long enough to be able to reproduce. Such ways of making a living in the world demand the development of sensitive sense organs, and the capacity to register and interpret the data provided by those sense organs, to compare it with past experience and, even more, with the outcomes of that past experience. And this is what learning and memory are all about. It is not the only route to evolutionary success. After all, bacteria do pretty well without either brains or nervous systems, or even much by way of memory – though there have been some disputed claims that they can learn from experience.