Want to eradicate viruses? They made us who we are

It is cold and flu season so many of us are currently under the weather with a virus. But what exactly is a virus? And are they even alive? Outside a host cell, these weird microscopic particles, or virions, only consist of a tiny piece of genetic information (about 10,000 times less than that contained in the human genome) and a protein or lipid (fatty molecule) shell. Whether these particles are living things is the subject of much debate, as they don’t meet many of the usual criteria for life. While there isn’t any formal agreement on what defines life, most definitions include the ability to adapt to the environment, to reproduce, to respond to stimuli, and to use energy. While the virus particle may fall short of the definition of life depending on the criteria used, for some virologists like myself, thinking of the virion as the “virus” is like calling a...