This thought paved the way for the concept of a “genetic program,” akin to a computer program – a metaphor that became almost self-evident when the structure of DNA was discovered, because DNA could be visualized as a linear string of symbols, which is exactly what computers read as a program. Like a computer program, DNA does not preserve the final state of what it codes for; rather, it embeds in a symbolic but concrete way (it is a real “text”) the relationships between all the objects and agents that it specifies and controls.