We should decide what kind of life there should be. We should invest in technologies that allow us to maintain biological diversity and perhaps even increase it. Some might even argue that humans have a particular moral obligation to re-introduce species whose extinction they caused, either directly, as is likely in the case of the mammoth, or indirectly, as a result of global climatic disruption. The value of re-creating mammoth might consist largely in satisfying intrinsic human curiosity. But, creating or re-creating some kinds of life forms may also be of great instrumental value to human beings, say in blocking the emergence of pathogens, or in helping to ensure the continued existence of life on the planet.