Figure 1.

Theoretical plot illustrating the notions of consistency over the ontogeny, GAIs and selection on the genetic correlation between trait 1 and trait 2. In (a,b), each line represents one individual, which is reported as a point in (c,d). In (a), the rank order of the individuals' breeding values for trait 1 remains stable across ontogeny. In (b), the rank order of the breeding values for trait 2 is different in young and adults because of GAI. As a consequence, the positive genetic correlation between trait 1 and trait 2 in young individuals (c) disappears in adults (d). Figures (e) and (f) represent the breeding values of nestlings that recruited (red) or not (grey), assuming a 5% recruitment probability. In (e), the breeding values of the two traits are not negatively correlated in recruits, which is why the genetic correlation is 0 when these individuals are measured as adults. In (f), the individuals are selected randomly and thus the correlation stays negative when they are measured as adults. (Online version in colour.)