The NIH has issued guidelines proposing the resumption of experiments using human stem cells to create animal embryos that are partly human. The idea is to grow human organs inside animals for use in research into diseases. NIH has crafted restrictions to avoid endowing animals with human consciousness or producing human embryos inside animals. Anyone who watched “Jurassic Park” knows all too well that nature doesn’t always respect our wishes for neat boundaries and tidy outcomes when it comes to living things. “Jurassic Park” was fiction, but does anyone think we are certain to keep life from finding a way?