TY - JOUR T1 - Reticulate evolution is favoured in microbial niche switching JF - bioRxiv DO - 10.1101/033514 SP - 033514 AU - Eric J. Ma AU - Nichola J. Hill AU - Justin Zabilansky AU - Kyle Yuan AU - Jonathan A. Runstadler Y1 - 2015/01/01 UR - http://biorxiv.org/content/early/2015/12/03/033514.abstract N2 - Reticulate evolution is thought to accelerate the process of evolution beyond simple genetic drift and selection, helping to rapidly generate novel hybrids with combinations of adaptive traits. However, the long-standing dogma that reticulate evolutionary processes are likewise advantageous for switching ecological niches, as in microbial pathogen host switch events, has not been explicitly tested. We use data from the influenza genome sequencing project and a phylogenetic heuristic approach to show that reassortment, a reticulate evolutionary mechanism, predominates over mutational drift in transmission between different host species. Moreover, as host evolutionary distance increases, reassortment is increasingly favored. We conclude that the greater the quantitative difference between ecological niches, the greater the importance of reticulate evolutionary processes in overcoming niche barriers. ER -