While we have no definitive evidence of when the first virus emerged, we can speculate that, once created, viruses coevolved with their hosts. What role do viruses play in the evolution of life? Are viruses a fundamental force in shaping the trajectory of life on Earth? Did viruses shape our genome? Are viruses part of our genome? How much of today's human genome is virus? Is viral infection a force that drives biological evolution toward higher complexity?
Have we humans been selected by viruses? Luis Villarreal, the author of two books: Viruses and the Evolution of Life and Origin of Group Identity, has studied viruses for about 50 years. Luis Villarreal is the Founding Director of Center for Virus Research at UC Irvine. He conducted postdoctoral research in virology with Nobel laureate Paul Berg at Stanford University.