Gilbert Gottlieb's theory of probabilistic epigenesis replaced the nature-nurture dichotomy, and similar oppositions, with an integrated account of the development of the entire behavioral phenotype. In that theory, invariant developmental outcomes cannot be identified with an organism's 'nature,' if by that term is meant a set of predetermined and unalterable features, such as a genetic blueprint. All developmental outcomes result from dynamic interactions among a variety of factors. Some of those outcomes (such as behavior often labeled 'innate' or 'instinctive') are relatively invariant, but this invariance reflects a dynamic rather than a static constancy, ensured by a system of stable developmental interactions, not a predetermined set of instructions encoded in the genes.