VIDEO: What is Life? Is Death Real? What does it mean to be alive, biologically speaking? It's a surprisingly complex issue.
What Does It Mean to Be Alive? New Definition May Include Viruses An in-depth analysis of viral evolution gives evidence that they belong on the tree of life, despite long-held arguments for the contrary.
Life on Earth Emerged from Extraterrestrial Impacts Popular culture associates comets and meteors with ravage and ruin, but new studies show that without them, life as we know it might not exist.
