Abstract: Many environmentalists believe it is wrong for us to cause the extinction of any species, and that we ought to make sacrifices to protect threatened populations. On their surface, these sorts of claims often appear committed to the idea that species are intrinsically value. Early work in environmental ethics tried to systematize this approach. But these "non-anthropocentric" value theories ultimately proved challenging to defend, in part due to difficulties in precisely explaining what species are.
In this talk, I introduce a new framework for thinking about these questions that is not centered on species. According to my proposal, the proper target of environmentalists' evaluative concern is the irreplaceable design that is embodied by the individual organisms that make up a putative species. This approach can capture and justify many environmentalist attitudes without needing to attribute intrinsic value to species, enabling environmentalists to effectively sidestep a number of puzzling issues. I then illustrate how the Irreplaceable Design framework can help us identify conservation priorities and think through the ethics of genetically modifying other species and using gene editing in conservation biology.