The spectrum of possible duplicated gene fates is depicted according to the functional similarity between paralogues, where complete functional redundancy (far left) represents that the greatest degree of functional similarity that can be exhibited and pseudogenisation (far right) the least. Genes are represented by rectangles with their colour denoting their function (teal depicting the ancestral gene function; white depicting the loss of ancestral function; sky blue depicting an elaborated function as in the case of specialisation; and pink depicting new functionality as in the case of neofunctionalisation). Throughout the middle of the spectrum there exist a multitude of potential paralogous gene fates with all degrees of functional overlap possible between them. The experimentally determined fates of paralogues discussed in the present article (tbx-37/38; erd-2.1/erd-2.2; Hxk1/Hxk2; the Warthog family; bab1/bab2; and pdm2/nub) are mapped onto the spectrum.