Here is a pic of part of a mile-long bicycle path near Cambridge, England. The four colors represent the base pairs of the BRCA2 gene, mutations of which increase the risk of breast cancer. There are about 10,000 base pairs in the gene. The path was designed to increase awareness of breast cancer.
The path reminds me of one of those kiddie xylophones with each note a different color. It would be neat if the path were somehow rigged so that as you rode over it you heard the four-note song. A complete-genome bike path on this same scale would wrap around the Earth ten times!
Wouldn't it be fun to cycle with a friend along two parallel four-color xylophones, representing our individual genomes. Long stretches the same, of course, but every now and then those different notes in the four-note symphony that make us unique selves.