Variability is correlated with increasing repeat length, increasing purity, and decreasing unit size.

<p>Correlations were made using genotypes of repeats (2mers to 5mers) that were derived from genomes sequenced with a read length of at least 75 bases. Data points were plotted at each reference length bin interval that contained at least 25 repeats. The mean number of alleles (A) positively correlated with purity and (B) negatively correlated with unit size.