Rotational evolution as a function of the buoyancy radius. We illustrate the observations in black filled circles. The grey areas represent the rotation rates versus buoyancy radius covered when the metallicity varies from to , where the mean and the standard deviation of the observed sample are considered. The coloured solid lines are the evolutionary models for three typical masses of γ Dor stars: 1.4 M_⊙ in blue (top), 1.6 M_⊙ in green (middle) and 1.8 M_⊙ in red (bottom). In each panel, the three sets of models relate to the different initial conditions set up in Sect. 3: from top to bottom: disc locking at a period of 2.4 days during 3 Myrs, 3.9 days during 3 Myrs, and 7.2 days during 5 Myrs. Left: evolution of the angular momentum distribution has been calculated with transport by meridional circulation and shears (Z92). Right: solid-body rotation is enforced all along evolution. The x-axis has been inverted so that the behaviour with evolution goes from left to right.