Paul Bieniasz joins the TWiV team to talk about the co-option, millions of years ago, of an endogenous retrovirus envelope protein by hominid ancestors for host defense against viral infection.

Ted and Welkin inform the TWiV team how the evolution of ancient retroviruses can be inferred by their sequences in the genomes of modern mammals, and join in a discussion of virus dispersal during different methods for drying hands.

Vincent, Alan, and Kathy reveal how a retrovirus in the human genome keeps embryonic stem cells in a pluripotent state, from where they can differentiate into all cells of the body.

The TWiV team describes aphid control by using a viral capsid protein to deliver a spider toxin to plants, and a human endogenous retrovirus that enhances expression of a neuronal gene.

Vincent, Alan, Dickson and Rich answer listener questions about XMRV, yellow fever vaccine, virus-like particles, West Nile virus, amyotrophic lateral sclerosis and human endogenous retroviruses, multiplicity of infection, and how to make a poxvirus.

Vincent, Alan, and Rich answer listener questions about lab procedures, prokaryotes, endogenous retroviruses, the iPad and teaching, prions, mimivirus, splitting water with viruses, and the polio outbreak in Tajikistan.