"The beginning of each of us is our personal genome: it appears when we’re still smaller than a single cell, and from then on it remains with us forever, determining the rest of our lives. The genome is like a complex barcode. Because it’s very long and complex, each of us differs not only from the 8 billion people living on our planet today, but also from all more than 20 billion who existed since the emergence of humankind 200,000 years ago. And of course, ours isn’t like that of any other species that lived over the last 4 billion years—whether animals, plants, viruses, or archaea. What could be more individual than that?…"