The unprecedented diversity of the viral supergroup

Abstract

Viruses are tiny infectious agents that cause diseases in all living forms. Despite being very small in size, they are the most abundant and diverse entities on our planet. The shown image life places viruses along with other living organisms, Archaea, Bacteria, and Eukarya in a universal tree of life. Different morphotypes (shapes) possessed by different groups of viruses are also labeled at the bottom. RNA viruses are in red while DNA viruses are in blue. Remarkable, the tree of life predicts an early origin of RNA viruses harboring simpler designs such as filamentous or spherical forms. Complex designs and DNA viruses appear gradually in evolution. Asterisk indicates unified groups while different colored branches indicate statistical confidence in clustering.