Book excerpt: Advances in our scientific understanding and technological power in recent decades have dramatically amplified our capacity to intentionally manipulate complex ecological and biological systems. An implication of this is that biological and ecological problems are increasingly understood and approached from an engineering perspective. In environmental contexts, this is exemplified in the pursuits of geoengineering, designer ecosystems, and conservation cloning. In human health contexts, it is exemplified in the development of synthetic biology, bionanotechnology, and human enhancement technologies. Designer Biology: The Ethics of Intensively Engineering Biological and Ecological Systems consists of thirteen chapters (twelve of them original to the collection) that address the ethical issues raised by technological intervention and design across a broad range of biological and ecological systems. Among the technologies addressed are geoengineering, human enhancement, sex selection, genetic modification, and synthetic biology. This collection advances and enriches our understanding of the ethical issues raised by these technologies and identifies general lessons about the ethics of engineering complex biological and ecological systems that can be applied as new technologies and practices emerge. The insights that emerge will be especially valuable to students and scholars of environmental ethics, bioethics, or technology ethics.