In the 'Nature of Mutations II' thread a link was posted to a report on epigentic effects. There is a suggestion there that any multi-celled organism would tend to evolve a soma-germ-line distinction over time ... surely this would also cover other differentitions of cell-type.
Perhaps a step-back would be a slime-mould-like collective.
Some one just walked into CTB here and exclaimed that he would like to be reincarnated as a slime-md but when I asked what color this guy said it didnt matter. I laughed on purpose. NO- ANY cell type may not necessarily be indicated by evolutionary theory of a multicellar organism as the distribution need NOT work for current density-dependent best modeling theory(no matter my own disagreement about association vs commutation) as long as the set exists for any cell(ie geneic selectionist group vehicle by say cell death toxin-antidote module genetics contra Gould's reference to nonlinearity in his specific vision of physicality). One could argue against theory form someother nonlinearity however if the set needs denial either for ID or designing elite budgets. I may be able to reply in the affirmative if I do a littel reading beyond the words in what you had awating for me on this return.