Technological change often exposes unstated assumptions lurking in the law and makes them problematic, and patent law is no exception. Although the core mission of the patent system is to promote technological progress, path-breaking new technologies have not always been easily assimilated within its boundaries. The first wave of patent applications on advances in biotechnology in the 1970s illustrate some of the difficulties. Before that time, living organisms had generally been assumed to fall outside the range of patent-eligible subject matter under a timehonored exclusion for products of nature. But genetically engineered organisms, although derived from naturally occurring life forms, seemed to involve too much human intervention to ...