Here's something that I've wanted to know because it's related. Where exactly is the "3D geometry data" that defines for example, the shape of your skull, located? If cells need to differentiate themselves into structures like that, where is that specified? Sounds like membrane patterns and microtubule arrays according to Wells. But if those only come about under DNA control, then it's back to the DNA. But DNA doesn't hold "shape data" does it?
DNA's role in the development of an organism isn't that of a one-to-one blueprint, it is more like a recipe. An embryo develops from bottom-up, localised rules.
Richard Dawkins in "The Greatest Show on Earth" writes:
The beautifully 'designed' body emerges as a consequence of rules being locally obeyed by individual cells, with no reference to anything that could be called an overall global plan.