As we have seen, this expectation pervades evolutionary thinking, and shows up again and again to be wrong. The once-we-thought-it-was-junk-but-now-we-see-how-it-works is a consistent theme in evolutionary thought. In recent years we've seen the so-called junk DNA turn up performing useful functions. More recently this story has repeated itself at the protein level. Designs that were once considered to be so much junk are now found to be essential. Evolution sure it helpful. Here is how one evolutionist described this latest rags-to-riches story:
Here we have a molecule that serves an important role in how cells function and survive, but it contains these puzzling 'junk' sequences that don't seem to have any apparent purpose. Our work suggests that this disorder is really a way of creating flexibility, allowing the protein to function as a molecular switch, a process that is thought to go wrong in certain diseases.
Evolution has provided researchers with convenient modular structures, areas that are repeated over and over again to make up proteins, and so we tend to dismiss the interspersed disordered sequences that don't seem to have any definable structure. Here we show that the weak molecular interactions in a disorganized protein equence are essential in giving this protein its unique attributes.
Well it is good to see that evolution has been helping researchers by providing convenient modular structures. At least evolution does something right.