How duplicate genes provide genetic robustness remains an unresolved question. We have examined the duplicated histone deacetylases Sir2p and Hst1p in Saccharomyces cerevisiae and find that these paralogs with non-overlapping functions can provide genetic robustness against null mutations through a substitution mechanism. Hst1p is an NAD(+)-dependent histone deacetylase that acts with... https://www.roneverhart.com/Viking-K2-Slide-Gate-Opener-SPS-Model/