Reproduction by cyclical parthenogenesis (CP) is con- sidered to be conducive to both colonization of new habitats (founder events) and rapid evolution of ecolog- ically relevant traits (Lynch 1985). During the partheno- genetic phase of reproduction, selection acts on the total phenotype of an individual clone, and not on individual traits ⁄ loci. This clonal selection spans the entire gen- ome, resulting in a ‘build-up of hidden genetic vari- ance’ between clones (Lynch 1985). However, during the sexual phase, linkage disequilibrium between loci is eroded, and the genetic variation accumulated during the parthenogenetic phase is released and expressed phenotypically in the population (Lynch & Gabriel
1983; Lynch 1985). This synergistic selection environ- ment of CP is considered to have the potential to accel- erate the evolution of ecologically relevant traits and local adaptation. Moreover, strong local adaptation can result in rapid monopolization of resources by the resi- dent genotypes, which can generate a priority effect against subsequent colonists (De Meester 1996; De Me- ester et al. 2002), as well as adaptive divergence in life history traits (Pfrender et al. 2000). For example, one such by-product of local adaptation can be changes in the timing of sexual reproduction itself (temporal isola- tion), a particularly effective mechanism for restricting gene flow (Deng 1997; Jankowski & Straile 2004).