RT Journal Article SR Electronic T1 Reticulate evolution is favoured in microbial niche switching JF bioRxiv FD Cold Spring Harbor Laboratory SP 033514 DO 10.1101/033514 A1 Eric J. Ma A1 Nichola J. Hill A1 Justin Zabilansky A1 Kyle Yuan A1 Jonathan A. Runstadler YR 2015 UL http://biorxiv.org/content/early/2015/12/02/033514.abstract AB 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.