Fig. 2

A general depiction of genotype-by-environment interactions and reaction norms. Each genotype exhibits a different response to varying durations of light exposure. Some genotypes, such as Aa, display average performance across different environmental conditions, while the AA and aa genotypes may differ. Additionally, when the lines of reaction norm are not parallel, it indicates the presence of genotype-by-environment interaction (Redrawn with permission from Alvarez-Castro 2024). A very similar family of curves are also found in Gupta and Lewontin (1982) and Lewontin (2006). For simplicity, curvilinear effects are not shown