> The question I don't think he could really answer was 'how do the cells know when to stop?'
I'm likely missing something obvious but I'll ask anyway out of curiosity. How is this not handled by the well understood chemical gradient mechanisms covered in introductory texts on this topic? Essentially cells orient themselves within multiple overlapping chemical gradients. Those gradients are constructed iteratively, exhibiting increasingly complex spatial behavior at each iteration.
I'm likely missing something obvious but I'll ask anyway out of curiosity. How is this not handled by the well understood chemical gradient mechanisms covered in introductory texts on this topic? Essentially cells orient themselves within multiple overlapping chemical gradients. Those gradients are constructed iteratively, exhibiting increasingly complex spatial behavior at each iteration.