Evolutionary dynamics of avian influenza A virus in the natural reservoir

Abstract

Avian influenza viruses were thought to exist in a form of evolutionary stasis within their natural reservoirs, i.e. waterfowls. However, a recent study demonstrated very high evolutionary rates, with epidemic-like population growth, for individual influenza subtypes in both aquatic birds and poultry, suggesting the stasis theory may be incorrect. Yet the evolutionary dynamics of the influenza gene pool within one species of migratory waterfowl remains unclear. We therefore tested influenza virus population behavior by estimating rates of nucleotide substitution of the internal genes from different subtypes of influenza viruses exclusively from mallard ducks …