VIRUSES MUCK UP DARWIN’S TREE OF LIFE. “The tree concept is challenged by the occurrence of horizontal gene transfer and … by the omission of viruses. Viral genomics have revealed an unexpected size and distinctness of the viral DNA sequence space. Comparative genomics has shown elements of vertical evolution in some groups of viruses. Furthermore, structural biology has demonstrated links between viruses infecting the three domains of life.””
”
http://rstb.royalsocietypublishing.org/content/364/1527/2263.full