Principles for introducing new genes and species for conservation.

Introducing new genes and new species into ecosystems where they have not previously existed presents opportunities and complex, multivalue decisions for conservation biologists and the public. Both synthetic biology and conservation introductions offer potential benefits, such as avoiding extinctions and restoring ecological function, but also carry risks of unintended ecological consequences and raise social and moral concerns. Although the conservation community has attempted to establish guidelines for each new tool, there is a need for comprehensive principles that will enable conservation managers to navigate emerging technologies. Here, we combine biological, legal, social, cultural, and ethical considerations into an inclusive set of principles designed to facilitate the efforts of managers facing high-consequence conservation decisions by clarifying the stakes of inaction and action, along with the use of decision frameworks to integrate multiple considerations.