So what mechanism carries the information of how the body functions from generation to generation if not genes?
This is beside the point, as parent already explained what he meant in his first 2 sentences: "Physics. More specifically, 'conditions'".
So, yes, the laws of physics might be universal, but gravity is X here and N on the moon, pressure is Y here and M under the sea, temperature, etc...
Epigenetics as a concept can also be abused into a sort of neo-Lamarckism.
But good luck growing a healthy organism without its epigenetic landscape properly initialized