The variety of human virus evolution.

There have been many wise suggestions of ways that evolution may occur but those ways seem often hard to support with good examples. Viruses have proven to be replete with some of these items. This paper reviews work that shows: (1) very fast rates of evolution; (2) positive Darwinian selection with the selective pressure specifically identified; (3) viral reassortment; (4) grossly unequal rates of evolution depending upon the host of the virus; (5) accurate dating of the cenancestor, the most recent common ancestor; (6) correspondence between the evolutionary tree and the geography of the place of isolation; (7) punctuated molecular evolution; and (8) network evolution.