Estimated data requirement for resolving the five poorly supported regions. Each graph shows how average bootstrap support increases as a function of alignment length for three types of simulations: nonparametric resampling of the empirical alignment (orange), parametric simulation of data (blue) and parametric simulation followed by introduction of missing data (gray). The approximate amount of data required to resolve a region can be derived for each simulation type by specifying a desired level of bootstrap support (e.g., the dashed line drawn at 80) and deducing the corresponding alignment length on the x-axis. Note that the x-axis uses a logarithmic scale. The lines connect the means of the five values of each condition.