Comparisons between rDNA copy numbers and population variables. (a) Consistent lack of correlation between different rDNA cluster copy numbers (18S and 5S) in males (blue, y = 1.61x + 0.83, R2 = 0.24) and females (pink, y = 0.78x + 1.06, R2 = 0.19). (b) Consistent weak correlation between different rDNA cluster copy numbers (18S and 5S) in hispanic (green, y = 1.20x + 0.72, R2 = 0.37) and non-hispanic white (orange, y = 1.75x + 0.87, R2 = 0.30) individuals. (c) Consistent lack of correlation between 18S and 5S rDNA copy numbers as a function of age of blood donor. All values in this graph are represented as rDNA copy number relative to tRNAMet, and normalized to the lab standard.