My understanding is that molecular gradients tell a cell its “map coordinates” in the developing body, and it uses that information to decide what sort of cell it should be and what cells it should divide into. Of course, the details are much more complicated than that, and the ultimate answer is that nobody really knows, yet.
Here’s an article with too much information:
https://pubmed.ncbi.nlm.nih.gov/19711444/
The question of whether current theories of evolution are adequately defended is an entirely separate one.
it has to do with the electronic pulse given off by the central nervous system and the distance or strength of that pulse. formulating a mutation that coincides with the needed cell for that particular organ. redundant with the energy being drawn from the placenta as in a sort of mapping device.
based on nothing at all except a clear night’s sleep at a holiday inn.