The capacity to blunder slightly is the real marvel of DNA. Without this special attribute, we would still be anaerobic bacteria and there would be no music.
Lewis Thomas, biologist, 1979
This nicely points out the other side of the double-edged sword of genetic mutations, which often are considered to be evil without exception. In fact, the human body makes every effort to prevent them, and even will send his own cells to death without hesitation if they are affected.
But equally, every once in a while, they will give rise to new life, when they from a new organism, that has improved it’s adaptations to it’s world.
This way, genetic mutations maintain variety and richness of life.