When you get right down to it—and by "right down to it," I mean at the DNA level—we are far more like one another than most of us would care to admit. It is estimated that we are 99 percent genetically identical, with that varying 1 percent causing quite a lot of variance. (The 1 percent explains, for instance, why I'm writing this column instead of sprinting in the Olympics or starring as the next James Bond.) An ever-growing body of research is also demonstrating how some of these differences put us at risk for a variety of diseases, including cancer, Alzheimer’s, and disorders that affect the immune system. Many of these differences are as small as one can imagine: a single change in the order of our DNA.
As I learned in college, and children now learn in elementary school, DNA is made up of four letters, or nucleotides: ...
