How are you different?Our history is written in our genes. Your genes tell your body how to make all the different proteins it needs to survive, develop and grow. A change (DNA mutation) in a gene can alter what it does, so the body makes a slightly different protein. Different versions of genes are called alleles. The types and numbers of alleles in a population can provide clues about the lives of our ancestors: their diet and the diseases they encountered.
Can we evolve disease resistance?
Can you drink milk?
In some parts of the world, certain adults cannot drink large amounts of milk because they are unable to digest lactose, the sugar found in milk. Drinking fresh milk causes discomfort and diarrhoea, but they can eat dairy products treated to break down lactose – like yoghurt. In other parts of the world most people have a version of a gene (allele) that allows them to digest lactose in adulthood. This characteristic probably spread through some populations thousands of years ago, as their ancestors began farming cattle.