[TalonDJ]

Why doesn't the DNA simply decay or dissipate? Where is the maintenance crew that keeps it going?

There are enzyme systems that DO act as maintenance crews to repair dna damaged by radiation and decay.

[dr_lew]

These enzymes are, of course, coded for in the DNA, activated by mechanisms coded for in the DNA, etc. etc. etc. All cellular activity transpires spontaneously, and in accord with physical law, without the direction or intervention of any external agent.