Everything changes over time and this can help us when we are trying to find the age of things.

Styles in most things from phones, to clothes, to the food we eat keep on changing - just think about how mobile phones have changed over the last ten years.

The same happens in the natural world - animals, plants and even landscapes are always changing. So if we study how they have changed through time, and we try to put them in some sort of order, we might be able to find some clues to help us date things.

Changes can be dramatic or they can be very slight and slow. Things can change on purpose to improve how they work or look, they may change in order to survive or because the environment is changing. This can even happen purely by chance.

Living things change to survive in competition with other wildlife or to exploit food sources and their surroundings. Manufactured things change as new materials are discovered, theories and beliefs are altered, improvements are needed and fashion is updated.

By studying a group of objects, like shoes, through time we should be able to put them order according to the changes in styles. If we were to find an odd shoe and we didn’t know how old it was, we could compare it to the list we have and maybe work out where it comes in the sequence – we wouldn’t be able to say exactly how old it was, but we would know it came before one and after another – we would know its Relative age.