FIGURE 2.

CRC (cause-response-consequence) model of global change driver acting upon lineages (or geographic populations within a lineage) composed of different genotypes. A global change driver affects the lineage which consists of highly plastic genotypes with respect to the driver (A), moderate plasticity with respect to the driver (B), and low plasticity with respect to the driver (C). Plasticity refers to phenotypic plasticity in fitness-related traits (reproduction and productivity), thus affecting the genotype’s acclimation and adaptation capacity. The genotypes respond differently to the driver depending on their phenotypic plasticity; likely responses are acclimation, increased fitness, range expansion, range shift, or local extinction. Acclimation is the response to the environmental driver that results in similar or increased fitness. This scenario will likely lead to range expansion. A range shift occurs from the natural range of occurrence, which is the current distribution range including the native range for native lineages and the presently invaded range for introduced lineages. The responses can be mediated by interacting environmental drivers. The ultimate consequence of the responses to the effect are impoverished genetic diversity, including lineages with lower phenotypic plasticity and fewer, but better adapted genotypes, or a lineage shifting into a new range less or differently affected by the global change driver.