This book investigates the challenges to modern patent law, particularly from the rapid developments in biotechnology. The subject of patent law is not dealt with in isolation; it is considered in the contexts of environmental law, trade law and European law in order to position patent law in its proper place in the real world, which is both global and dynamic. The book focuses on human gene patents, patents in the animal world, and the pressures put on the patent system by the climate change debate. It examines the issue of the expansion of patentability which has been prompted by these areas. Besides dealing with challenges to patent law the book also examines several issues subordinate to the main question, such as the patenting of complex biological systems in humans and animals, and the pressures put on the patent system by technological developments.