In a way, sequencing DNA is very simple: There's a molecule, you look at it, and you write down what you find. You'd think it would be easy—and, for any one letter in the sequence, it is. The problem ...

Add Yahoo as a preferred source to see more of our stories on Google. Does the order in which you eat your food affect your health? (Getty Images) (apomares via Getty Images) Dietitians and doctors ...