Gene overlap is extremely rare actually! When phiX174 was first discovered, some researchers wondered if such a complexly intertwined system could even have ev

Gene overlap is extremely rare actually! When phiX174 was first discovered, some researchers wondered if such a complexly intertwined system could even have evolved naturally, or if it might suggest that the virus was hand-engineered: http://adsabs.harvard.edu/abs/1979Icar...38..148Y http://adsabs.harvard.edu/abs/1979Icar...38..148Y