Laws that establish legal rights for nature are being pursued in a growing number of countries to protect the environment. The success or failure of these rights-of-nature laws can depend in large part on how scientific concepts and expertise have been used to develop, interpret, and implement them. Epstein et al. reviewed key scientific aspects of rights-of-nature laws and the use of science in court decisions that have interpreted them. They examined the “right to evolve” to illustrate challenges in applying scientific concepts in rights-of-nature laws and identify some possible solutions. —Brad Wible