Questioning the Ubiquity of Neofunctionalization
Figure 4
Neofunctionalization vs. concurrent gene duplication and subfunctionalization.
(A1) Gene duplication. Shown also are two additional proteins elsewhere in the network. (A2) According to He and Zhang (2005), additional interactions gained by paralogous pairs over time are explained by the formation of de novo interactions. (A3) The resulting network. (B1) Gene duplication. (B2) An interacting partner duplicates, including the loss of a redundant interaction. (B3) Another partner duplicates and loses a redundant interaction. (B4) The resulting network is indistinguishable from that postulated for neofunctionalization.