A stochastic model for the evolution of the influenza virus
arXiv:1302.2362
Abstract
Consider a birth and death chain to model the number of types of a given virus. Each type gives birth to a new type at rate and dies at rate 1. Each type is also assigned a fitness. When a death occurs either the least fit type dies (with probability ) or we kill a type at random (with probability ). We show that this random killing has a large effect (for any ) on the behavior of the model when . The behavior of the model with and is consistent with features of the phylogenetic tree of influenza.