" It is a process running in circles-in circles which get narrower, like the coils of a spiral, as the cell becomes more and more specialised. The genes control the activities of the cell by relatively simple coded instructions which are spelt out in the complex operations of the cell-body. But the activities of the genes are in turn guided by feedbacks from the cell-body, which is exposed to the hierarchy of environments. this contains, apart from the chemical triggers, a number of other factors in the 'epigenetic landscape' which are relevant to the cell's future, and about which the genes must be informed. "

― Arthur Koestler , The Ghost in the Machine