Figure 3.

Permutation test results for the shape changes in the right 12th female rib. The dotted line represents the test statistic, λ'. Areas to the left of the test statistic line represent cases where the random combination model had a better (lower) sum of variance, λ, than the regression model. Areas to the right of the test statistic line represent cases where the regression model had a better (lower) sum of variance, λ, than the random combination model. In this example, the sum of the probabilities to the left of the line (P = 0.0004) indicated that only 0.04% of the random combination models had a lower sum of variance than the regression model. Thus, the null hypothesis should be rejected and significant shape changes occur in the right 12th female rib with age.