Another in a series focusing on viral characteristics, returning guest Luis Villarreal graces listeners with an in-depth and elegant collection of thoughts on how viruses behave.

He shares a lifetime of knowledge, discussing

• What a virus' ability to communicate meaningful biological information adds to the "are viruses living" question,
• How our very immune system existence may stem from virus-cell interaction, and
• Why we need to rethink how "fitness" works as a virus evolution impact factor.

Luis Villarreal is a professor emeritus in the Department of Molecular Biology and Biochemistry at the University of California, Irvine, and is the founding director of The Center for Virus Research. He's spent the bulk of his career on virology. His fascination began when he came across an image of a crystalline array of an RNA virus in the cytoplasm of an infected cell.

He was intrigued by the interface of life and chemistry and it struck him that all viruses existed in that interface. Therefore, when Richard asks if "viruses are living or nonliving," he verbalizes the answer in terms of this interface, emphasizing that viruses have always provided one of the more important or crucial aspects of communication into all living entities. This communication is essential in virus-host cell interaction.

The conversation continues in this same tenor, characterizing viruses as existing in dynamic relationships that determine virus evolution over time. He offers HIV as an example of addressing the seat of control with the host cell versus the virus. After HIV infection, other viruses in human cells started to reactivate because of this give-and-take control dynamic: there's no one controlling factor or outcome. Rather, it's all about biological strategies clashing.

Stories about these clashes continue through the discussion, and he address the origin and evolution of viruses and how viruses persist with answers that take all elements of these dynamic relationships into account, including one example from a graduate school undiluted viral passage study. He found that the eventual defective virus that evolved, which was what might be termed "unfit," exerted tremendous control over the infective virus. Perhaps, he adds, we need to reimage how we apply evolutionary biology to viruses.

For examples of his work, find numerous listing in ResearchGate.

Available on Apple Podcasts: apple.co/2Os0myK