Proteins consist of hundreds of amino acids attached to each other like train cars, and when they fold up they consistently find the same three dimensional shape. Like a necklace that magically falls into the same shape every time it is dropped onto a table, the consistency of protein folding once seemed like a paradox. For there is an astronomical number of shapes the protein could possibly take on. How does it find the same one so consistently, and so quickly? The answer has interesting implications for evolution. Read more