The Galápagos Islands are often called a natural laboratory of evolution. This metaphor provides a powerful way of understanding space that, through scientific research, conservation and tourism, has shaped the archipelago over the past century. Combining environmental histories of field science with political ecologies of conservation biopower, this article foregrounds the territorial production of the archipelago as a living laboratory. In the mid-twentieth century, foreign naturalists used the metaphor to make land claims as they campaigned to create the Galápagos National Park and Charles Darwin Research Station. Unlike earlier ‘parks for science’, these institutions were not established under colonial rule, but through postwar institutions of transnational environmental governance that nonetheless continued colonial approaches to nature protection. In the following decades, the metaphor became a rationale for territorial management through biopolitical strategies designed to ensure isolation by controlling human access and introduced species. This article’s approach extends the scope of what is at stake in histories of field science: not only the production of knowledge and authority of knowledge claims, but also the foundation of global environmental governance and authority over life and death in particular places. Yet while the natural laboratory was a powerful geographical imagination, analysis shows that it was also an unsustainable goal.