A viruss host range determines which host it can acquire AMGs from. Additionally, the abundance of a host surrounding a virus will affect its likelihood to acquire genes from the host. Virus populations increasingly occupy lytic lifestyles as bacterial production increases. The strong evolutionary connection between viruses and their hosts makes AMG acquisition mirror the hosts own adaptation to its environment over time.
Synechococcus and Prochlorococcus are the most abundant picocyanobacteria, accounting for up to 50% of primary production in the marine environment. As such, many AMGs characterized have been discovered in phages of these host systems.