Primate genome size variation. Repetitive and unique portions of aligned orthologous sequences were identified by RepeatMasker (version 3.0, slow option). Relative fractions were based on the larger primate genome. Significance of the difference in genome size was determined by a permutation test (10,000 replicates, see Methods). Asterisks over species bars indicate significant differences in overall lengths, and those between species bars indicate significant differences in either repetitive or unique lengths between two species. *,P < 0.05; **, P < 0.01.