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How are new alleles created?
Occasionally, DNA mutations occur in germ cells – cells destined to become eggs or sperm. In this case, the DNA mutation is copied into every new cell of the growing embryo following fertilisation. In this way, new DNA variants are passed on to the next generation. If the mutation affects a gene, it will result in a new version of that gene – a new allele.
What are mutations?
Genetic conditions are caused by DNA mutations that cause a change in one of the genes affecting the way the body works or develops. These gene variants can then be passed from generation to generation. There are over 5000 different genetic conditions, which together affect over two million people in the UK. Some genetic conditions, like cystic fibrosis and sickle-cell disease, can cause serious health problems for people who inherit them.
Why are mutations important?
All living creatures have genes, made up of DNA. Without DNA mutations, life on Earth could not have evolved. Mutations can affect the way a gene works, which may in turn cause changes in an animal's appearance, or behaviour. Sometimes, a new gene variant may mean the animal is better adapted to its surroundings, improving its chances of survival. So this animal is more likely to have offspring, which will inherit the beneficial gene variant. This process is called natural selection.
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DNA mutations are important for evolution.
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