UNPARALLELED DIVERSITY. “The virus world displays an enormous diversity of genome structures and sizes (viral genomes consist of single-stranded (ss) or double-stranded (ds) RNA or DNA and range in size from less than 2 kb to over 2 Mb), replication and expression mechanisms, and virion structure.”
http://onlinelibrary.wiley.com/doi/10.1111/nyas.12728/full