 The morphospace describes actual coiling patterns and merely possible ones, and raises explananda for evolutionary biologists. Why did certain coiling patterns evolve and not others? Maclaurin and Sterelny claim morphospaces will be of low dimensionality and specifically limited to lineages or clades (Maclaurin &amp; Sterelny 2008: 75–9). Thus, biologists must be assured that the variables included are representative of the phenotypic traits of the organisms and hence species under study. They hypothesize that the variables will correspond to developmental modules or mosaics, which are a relatively independent developmental system that contributes to fitness (G. P. Wagner 2014; P. J. Wagner 1995). This approach of course assumes that there exist independent developmental systems, and ideally it would help articulate how a lineage would fare over time as a function of its plasticity.