" Your genome is the totality of your DNA, 3 billion letters of it, and due to the way it comes together – by the mysterious (from a biological point of view) business of sex – it is unique to you. Not only is this genetic fingerprint yours alone, it’s unlike any other of the 107 billion people who have ever lived. That applies even if you are an identical twin, whose genomes begin their existence indistinguishable, but inch away from each other moments after conception. In the "

― Adam Rutherford , A Brief History of Everyone Who Ever Lived: The Stories in Our Genes