Evolution is the term we use to describe the changes that take place in plants and animals over a period of time. It is thought that the first life forms on Earth over 3000 million years ago were simple single celled craetures. Over many millions of years these evolved into the plants and animals that we now see.
It was Charles Darwin who carried out work looking at the process of natural selection and how livings things adapt in order to survive. His theory suggested:
1. That there is variation within species as a result of genetic and environmental differences.
2. Because of this variation some members of a species are better able to survive. This lead to the idea of survival of the fittest where some members of a species are more able to fight disease, avoid predators, compete for food and shelter and adapt to an ever changing environemnt.
3. That the changes that do take place are a result of adaptation.
