Fig. 4

Gene sampling sufficiency (ζ) and terrace properties. ζ: scaled ratio of the number of genes present in the data set and the theoretical minimum number of genes needed for the data set to be decisive. A decisive data set induces a terrace of only one tree. ζ > =0: number of genes is sufficient for the data to achieve decisiveness. ζ < 0: number of genes is insufficient. a. Rank-order ζ of the 26 data sets. The number of genes is sufficient to achieve data decisiveness in only 6 data sets. b. and c. Terrace size and consensus tree ρ plotted as a function of ζ. The data point above the plot in b. represents the largest, 10³⁸⁸-tree terrace. Black dots mark the ζ values of data sets for which we terminated terrace tree enumeration or consensus tree assembly before completion