We are living in what is widely considered the sixth major extinction. Most ecologists believe that biodiversity is disappearing at an alarming rate, with up to 150 species going extinct per day according to scientists working with the United Nations Convention on Biological Diversity. Part of the reason the loss signified by biological extinction feels painful is that it seems irremediable. These creatures are gone, and there's nothing to be done about it. In recent years, however, the possibility has been broached that, just possibly, something can be done, in at least some cases. Human ingenuity, a contributing factor in the extinction crisis, might achieve their "de-extinction"-in at least some cases, and with sometimes significant qualifications about whether the original species had been "recreated" and whether it could resume its original place in the environment. De-extinction is an entry point into a larger set of questions about how biotechnological tools can support, coexist with, or undermine the goals of conservation and about the very meaning of conservation. Are we beings in control of the world or beings who prosper by accommodating ourselves to webs of symbiotic interdependencies? Are we creators or creatures, or both-and if both, then how can we achieve the balance between them that might be called humility? The interplay of perfecting and accommodating is not unique to human beings-perhaps it characterizes all forms of life on Earth-but with humans, these modes of being are distinctive, and our technology greatly expands their scale and effects. It is such questions that the ten essays in this special report explore.