We are asking for your help in drawing a detailed genetic map of Britain, which we hope will tell us a lot about the history of the British people. These are the kinds of questions we hope to answer with the new map. Many things pass down to us from our ancestors - for example our names, our language and our customs. But there is also something else - our genes.
Genes are the instructions our body uses to run things.
For instance, they tell bone cells how and when to make bone, hair cells to make hair and stomach cells to make the enzymes we need to break down our food. Genes are made of a very long chemical molecule called DNA, which is composed of only four units. The complicated instructions are contained in the order of these units in the same way that words are formed by putting letters in a certain order. New ways of looking at DNA that have been developed in the last few years now make it feasible to look for traces of these different histories within the genes we now carry. She got it from her mother, who got it from hers and so on back along a maternal line into the remote past.