In with the Old, in with the New: The Promiscuity of the Duplication Process Engenders Diverse Pathways for Novel Gene Creation

Figure 1

Different evolutionary fates of gene paralogs under Ohno’s canonical model of gene duplicate evolution [16]. Ohno postulated that gene duplicates are born redundant in sequence and function to the ancestral copy. As such, either copy (ancestral or derived) has the potential to assume the identity of the locus maintaining the ancestral function leaving the other paralog free to accumulate mutations that may in turn engender vastly different evolutionary outcomes, namely loss of function (nonfunctionalization) or gain of a new function (neofunctionalization). A third evolutionary outcome not displayed in the schematic is the conservation of the ancestral function by both paralogs, in instances where natural selection favours increased gene dosage for increased levels of the ancestral gene product.