Jakob Vinther was the first person who figured out that you could tell what colors dinosaurs were by looking at melanosomes, the tiny bags that hold pigments in a cell.

The first time he discovered the melanosomes in dinosaur fossils, he was just a graduate student. Elated, he immediately sent photos of them to his mentor, Derek Briggs. Briggs almost laughed. He informed Vinther that those little things on the electron microscope photos were, sadly, just bacteria. Many paleontologists had observed them, over decades.

Of course, it turned out that the little dots were not bacteria but in fact melanosomes. By the shape and size of the melanosomes, it is now possible to decipher the colorings of dinosaurs that lived hundreds of millions of years ago.

This story is very similar to the story of exosomes. When exosomes were first discovered, they were also hiding in plain sight. The exosomes were seen in virtually every cell culture, every day, by thousands of researchers. They were thought to be detritus from cells dying and breaking down. Now of course, they’re known to be one of the most important, if not the most important cell to cell communication system.

You see this played out over and over. And I’m not talking about things that are seen rarely where the scientist doesn’t appreciate the significance. For example, the first scientist to see RNA interference thought little of it, but RNA interference isn’t something that you routinely see every day unless you’re looking for it.

No, I’m talking about something that scientists see every day but filter out of their thoughts because they think it’s unimportant. Something that is so common that people think “if that were important, it would have been recognized by now.”

I think these may be more common than we think. One example is the fact that we need to add insulin to cell line cultures, including tumor cell lines, in order to get them to grow. There is now a growing recognition that obesity-related cancers may actually be better termed insulin-related cancers. Despite the fact that it was plain that insulin is a growth factor and that growth factors can cause cancers, this property of insulin has been ignored for a long time, Perhaps that is why newcomers to a field, with a fresh lens, can bring new insights.