Viral eukaryogenesis

Viral eukaryogenesis is the hypothesis, proposed by Philip Bell in 2001, that the cell nucleus of eukaryotic life forms evolved from a large DNA virus in a form of endosymbiosis within an archaea cell. The theory has gained support as large complex DNA viruses capable of protein biosynthesis (such as Mimivirus) have been discovered.

A number of precepts in the theory are possible. For instance, a helical virus with a bilipid envelope bears a distinct resemblance to a highly simplified cellular nucleus (ie: a DNA chromosome encapsulated within a lipid membrane). To consider the concept logically, a large DNA virus would take control of a bacterial or archaeal cell. Instead of replicating and destroying the host cell, it would remain within the cell. With the virus in control of the host cell's molecular machinery it would effectively become a "nucleus" of sorts. Through the processes of mitosis and cytokinesis, the virus would thus hijack the entire cell&mdash;an extremely favourable way to ensure its survival.