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 Advancesjust 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.