Quasispecies theory revolutionized our understanding of viral evolution by describing viruses as dynamic populations of genetically diverse variants constantly adapting. This article explores the theory’s role in virus-host interactions, including immune evasion, drug resistance, and viral emergence. We review the original model, recent advances, and key virus dynamics needing incorporation into quasispecies theory. We introduce the ultracube concept as a more realistic multidimensional sequence space to investigate virus evolutionary dynamics.
The quasispecies theory, conceived by Manfred Eigen and Peter Schuster more than fifty years ago1,2,3,4 was developed to investigate the dynamics of biological information in replicators subjected to exceptionally high mutation rates. This theory is a cornerstone in understanding prebiotic evolution and a new framework