Genes: Fate and Choice
Siddhartha Mukherjee:
Genes must carry out programmed responses to environments – otherwise, there would be no conserved form. But they must also leave exactly enough room for the vagaries of chance to stick. We call this intersection ‘fate.’ We call our responses to it ‘choice.’ An upright organism with opposable thumbs is thus built from a script, but built to go off script. We call one such unique variant of one such organism a “self.”
The Gene, p. 390.