Clones/genotypes
The degree of expression plasticity commonly varies between clones (morphological defense, Havel 1985; Spitze 1992; Hammill et al. 2008; Miyakawa et al. 2015; Boeing et al. 2006; Rabus et al. 2011; Weider 1985; Declerck and Weber 2003; Jeyasingh Weider 2005; Lively et al. 2000; Ferrari et al. 2001; WiÄ…ckowski et al. 2003; Dennis et al. 2011, life-history traits De Meester 1993; Weider and Pijanowska 1993, behavioral traits Michels et al. 2007). Interclonal variation in the expression of inducible defenses in clones originating from habitats with different predation regimes (Boersma et al. 1998; Boeing et al. 2006a; Dennis et al. 2010). The inter-clonal variations in the type and degree of inducible defense of Daphnia hyalina result from seasonal variations in the clonal composition of field populations (Havel 1985; Stibor and Lampert 2000). Moreover, this might partly account for the seasonally different occurrence of defended and undefended morphs in the field, caused by changing predator regimes (Havel 1985). The variation in degree of expression inducible defense is predicted might be greater between species than between clones, although no comparisons have been made. However clonal variations are not negligible or small enough to be ignored. If the variation in the degree of plasticity is greater for clonal variation than for interspecific variation, then natural selection might be working strongly within the species.