seems to me that when the original generation of organs, bones, and other structure is occurring, there is a chemical soup of proteins/hormones/etc that provide

seems to me that when the original generation of organs, bones, and other structure is occurring, there is a chemical soup of proteins/hormones/etc that provides the right environment for a whole host of gene expressions not seen after the generation is done and the organism is more or less fully formed. recreating that environment seems challenging. it's like getting back to bios after you already booted the OS.