>>4611137Well, it is a bit obvious that your familiarity does have its limits: when you only learn these things from a theoretical perspective then you automatically develop the impression that things are imprecise, merely though your own apprehension at lack of understanding the whole picture.
I can assure you that this procedure would not only NOT fail, it would always work to a greater or lesser extent. All of the techniques I am suggesting are well understood at this point and so there is little risk or variation involved in the results.
>>4611260That question has a very, very, very complicated answer. It is pretty hard to do what you are talking about, nearly verging on impossible to be honest. Let me see if I can explain this to you as simply as possible.
"what goes where" is determined by the patterning of genes called Homeotic genes, which exist in sets of seven. In their simplest expression, insects and arthropods, one set of seven homeotic genes creates a line of segments, and therefore a one dimensional line which makes up the entire bodyplan.
Now, through mutation, you can accidently end up with an extra set of homeotic genes, and since you already have the original copy, the new copy can be mutated over time to create new function. Basically what happens is you have your original one-dimensional bodyplan which exists in all higher animals, but some have evolved another "dimension" which blooms outwards from one of their segments. Now, this means that for each set of homeotic genes, you effectivly another dimension to the map of the bodyplan.
As previously stated, bugs and lobsters only have one set of homeotic genes, and are therefore one dimensional in their development.
Humans have six sets of homeotic genes. As one of my favorite professors once put it "Mammalian embryology is like watching someone do origami through a colliadescope; everything is constantly shifting and blooming into new form, and folding over itself".