Question: how to you think evaluation works?

anon answered on 19 Mar 2015:

Evolution explains how living things have changed over the history of life on earth, which includes all animals, as well as plants, bacteria and fungi… all the different types of living things are thought to have developed over time from simple life forms!

All living things are made up of cells. Cells contain DNA which is a code that works like instructions about what our features will be e.g. blue eyes or brown eyes. When cells are copied to make new cells, the DNA gets copied as well. Sometimes it isn’t copied perfectly which means the code changes a little bit. This change can be passed on to that animal’s future offspring (children) .

This often doesn’t make any difference to the offspring. But sometimes the change is bad or good. If the change is bad, then the children often die before they grow up to have children themselves, so the change doesn’t get passed on any more.

If the change is good in some way for example a change in the code means that a polar bear has a thicker, warmer fur coat that means it is better suited to its cold habitat, then it might survive to pass on that change to lots of its children. So when a change is good in some way it can gradually spread until all the animals of that species have the changed, useful feature.

This process of change is evolution. And it is very useful because it means that when the environment changes, living species are able to evolve to suit the new environment and survive because of the differences in their DNA codes! It is also why there are so many amazing and different type of animals on earth! Exciting!