Evolution of long-range fractal correlations and 1/f noise in DNA base sequences

A new method of quantifying correlations in symbolic sequences is applied to DNA nucleotides. Spectral density measurements of individual base positions demonstrate the ubiquity of low-frequency 1/f noise and long-range fractal correlations as well as prominent short-range periodicities. Ensemble averages over classifications in the GenBank databank (primate, invertebrate, plant, etc.) show systematic changes in spectral exponent with evolutionary category. © 1992 The American Physical Society.