I was nosing around you tube and found a Nova video entitled “What Darwin Never Knew“, July, 2012. What was particularly interesting to me was a section starting around one hour and four minutes into the video. Just prior to this, the video was talking about gene switches that turn other genes off and on. One of the investigators said such genes boss other genes around. This has a striking parallel to the concept of master and slave genes, models of which are discussed in this blog. In this case, the switches between the master and slave replicons are either left off or permanently turned on by partial fusion of the two adjacent replicons at a shared double origin of replication, generating a promoter region that can now be activated for gene transcription.