A co-option or more often co-optation is an election where members of a committee (or similar group) vote in order to fill a vacancy on that committee or group. Where a small committee is originally elected using a method of proportional representation a co-option may be thought unsuitable as the newly elected member will not necessarily represent the interests of the group represented by the vacating member.citation needed
Cooptation may also refer to the tactic of neutralizing or winning over a minority by assimilating them into the established group or culture. (see Philip Selznick, "TVA and the Grassroots" (1949))
In evolutionary biology, co-optation or exaptation describes the adaptation of an existing biological feature for a new purpose.
The haplodiploid sex determination scheme, which permits lone femaleinsects to colonize new environments by mating with male offspring, may contribute to the eusociality of ants and bees. (see S.J. Gould 'Quick lives and quirky changes', in Hen's teeth and horse's toes)