Influenza, SARS, Ebola, HIV, the common cold. All of us are quite familiar with these names. They are viruses—a little bit of genetic material (DNA or RNA) encapsulated in a protein coat. But what we don't really understand, and what scientists have struggled with since the study of virology began, is whether viruses are actually living or not. A paper published today in Science Advances just might change that. By creating a reliable method of studying viruses' long evolutionary history—hitherto nearly impossible—researchers have found new evidence that strongly suggests viruses are indeed living entities.

You probably remember when you had the chicken pox. Maybe you recall a few times you caught the flu. But you might have had some infections that you never even realized or that you don't remember. Even if you don't remember, your immune system does—it has special antibodies to combat those viruses should they ever return. Now researchers have developed a quick, inexpensive method called VirScan that can detect the viruses currently infecting a patient as well as those with which she was infected in the past, all from a tiny sample of blood. VirScan could help researchers better understand how the body combats viruses and virus' lasting effects. The researchers published an article outlining their method today in Science.

Even though mimiviruses are some of the largest viruses we know of, they measure only one tenth the width of a human hair at their largest. Understanding the structure of something so small is not an easy task, so researchers have been working to find different ways to look inside it. In a paper published today in Physical Review Letters, researchers from Uppsala University in Sweden used a new technique to make a 3D reconstruction of the large virus out of almost 200 x-ray snapshots.