Mysterious Pi and a Possible Link to DNA Sequencing

Pi is an eternal character of a circle, which has maximal area under constraint of fixed perimeter, so pi can be considered as an "optimal" number. DNA or RNA sequence is a result of nature selection, and it should be of an optimal sequence under necessary biological constraints. Is there any connection between pi and DNA sequence? The present work draws attention to such possibility. If we endow a quaternary digit (0,1,2,3) for adenine(A), cytosine(C), guanine(G), and thymine(T), respectively, we guess that the value of pi in quaternary system might hint an optimal sequence in DNA or RNA. An optimal number (pi/5=0.628) is introduced, which is slightly larger than the golden mean(0.618), the mysterious He Map (The River Map) is introduced, which has a history of several millennia, and its unsolved conundrum is partly solved, which is relative to pi.