Pathway
Cells in embryos make their way across a steep “developmental landscape” to their eventual fate.
Embryonic cells continuously monitor their changing surroundings and make small corrective adjustments, optimizing as development proceeds, locking in on their planned identity relatively late.
Processing positional information makes genes variously switch on and off throughout the embryo, giving cells distinct identities based on their location. (Some cells unfortunately take the wrong paths and are unable to get back on track.)
All the information is there in the landscape and processing that information effectively may be the phenomenon that makes a bunch of loosely stuck-together atoms behave like the thing we call life.
Had I been like a man living in a wood from which he knows there is no exit, I could have lived; but I was like one lost in a wood who, horrified at having lost his way, rushes about wishing to find the road.”
-Leo Tolstoy
