The correlation between CD and functional flexibility score (FFS) of the gene family calculated via equilogs using equation 1. This is evidence that structural determinant of designability, CD, serves as a direct influence on the number of functions that a gene family does, with linear fit correlation R = 0.97. Each datapoint represents a bin in FFS, with step 0.1 containing 50-200 families. The datapoints represent the average CD over all gene families represented in an FFS bin.