Likelihood analyses of ancestral ranges require a parameterized model that consists of a time-calibrated phylogeny, an ‘adjacency matrix’ of allowed or forbidden area connections, and an ‘area–dispersal’ matrix with probabilities for discrete periods of time. The approach is implemented in the software Lagrange. Because it can incorporate information about past continental positions, the approach has been used in historical biogeographical studies of relatively old clades. Surprisingly, no study has evaluated the interactions among these input matrices. Here we use the lily family Colchicaceae and artificial data to study the relative effect of the input matrices on final estimates.