DNA tests can tell people where in the world their ancestors came from, and if they're at risk of developing different genetic conditions. They can sometimes even help people connect with family ...

Our DNA is made of millions of combinations of the genomes that create the human body. Even the smallest changes in these sequences, or in how they act, can change the functioning of the whole body ...

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 ...