Fig. 2

Illustration of the adaptation of a breed to different environments. Illustrative example with a one-dimensional space \(\mathcal{E}\) of environments, and a one-dimensional space \(\mathcal{Y}\) of phenotypes. The trait of interest is body weight. A small body weight is preferred in environment \({e}_{1}\), while a large body weight is preferred in environment \({e}_{2}\), so breed \({b}_{1}\) is adapted to environment \({e}_{1}\), while breed \({b}_{2}\) is adapted to environment \({e}_{2}\). Note that not only the preferred body weight changes depending on the environment, but also the realized body weight. The animals get heavier in environment \({e}_{2}\), e.g., due to improved feed quality