" Viruses, for instance, perform a really irritating function of intermingling the DNA from every species on Earth with every other. As Richard Lewontin puts it . . . It used to be thought that new functions had to arise by mutations of the genes already possessed by a species and that the only way such mutations could spread was by the normal processes of reproduction. It is now clear that genetic material has moved during evolution from species to species by means of retroviruses and other transposable particles. . . . What is so extraordinary in its implications for evolution is that transposition can occur between forms of life that are quite different, between distantly related vertebrates, for example, or even between plants and bacteria. . . . Thus, the assumption that species are on independent evolutionary pathways, once they have diverged from each other and can no longer interbreed, is incorrect. All life-forms are in potential genetic contact and genetic exchanges between them are going on. . . . The evolutionary “tree of life” seems the wrong metaphor. Perhaps we should think of it as an elaborate bit of macramé.16 "

― Stephen Harrod Buhner , Plant Intelligence and the Imaginal Realm: Beyond the Doors of Perception into the Dreaming of Earth