How it’s being used
People have been breeding animals and new varieties of plants for many hundreds of years to develop or avoid certain qualities. Examples include racehorses that are bred to be faster and stronger, and roses, bred to give a wider range of colours and to make them more resistant to disease. Over many generations, sometimes for thousands of years, the world’s main food crops have been selected, crossed and bred to suit the conditions they are grown in and to make them tastier.
For example, cattle are bred according to whether they are for beef or dairy herds. Most of today’s dairy cattle are very different from the cattle that were originally domesticated. Over the years, dairy herd breeding has focused on increasing milk yield and on improving the quality of the milk.
But whereas traditional methods involve mixing thousands of genes, genetic modification allows just one individual gene, or a small number of genes, to be inserted in