Figure 2

Illustration of the Gompertz growth model. The Gompertz growth model is a sigmoid function described by three parameters; a (asymptote), b (lag phase) and c (maximal growth rate). Model parameters for each replicate panel with barnacles, were obtained by first fitting a model (thin lines) to shell diameter data (circles) for each barnacle on a panel (measurements at four different times) and then calculating an average model from these fittings for each replicate panel (thick line).