Figure 3. PDFs of the inter-nucleotide intervals A-A, T-T (open symbols); G-G, C-C (full symbols) in the DNA sequences from H. Sapiens and Bacteria full genomes (in scaled form).
Dashed lines show the best fits by a 
-exponential distribution 
. While in Bacteria the approximation by a single 
-exponential with 
and 
is possible, in H. Sapiens a sum of two 
-exponentials with 
and 
and 0.1 makes the best fit. To avoid overlapping, the PDFs for Bacteria are shifted downwards by two decades. For comparison, dotted lines show corresponding exponential PDFs.