Virus Evolution: Insights from an Experimental Approach

Viruses represent a serious problem faced by human and veterinary medicine and agronomy. New viruses are constantly emerging while old ones evolve and challenge the latest advances in antiviral pharmaceutics, thus generating tremendous social alarm, sanitary problems, and economical losses. However, they constitute very powerful tools for experimental evolution. These two faces of virology are tightly related because future antiviral treatments shall be rationally designed by considering evolutionary principles. Evidence indicates that the evolution of viruses is determined mainly by key features such as their small genomes, enormous population sizes, and short generation times, and at least for RNA viruses, large selection coefficients, antagonistic epistasis, and high mutation rates. We summarize recent advances in the field of experimental virus evolution. Increasing our understanding of the roles of selection, mutation, chance, and historical contingency on the ecology and epidemiology of viral infections could determine our ability to combat them.