The normative postulate problem: Hidden values in ecology, evolution, and conservation

The translation of scientific data, analyses, and conclusions into public policy and social action almost always contains an implication of the investigator's ethics and values. Direct statements of these values are often deeply considered, but the ethical implications of structural constraints and upstream analytical choices are often hidden. This is relatively uncontroversial from a philosophical point of view, and well-known to scholars in environmental ethics. However, many practitioners in ecology and evolution without such training (ourselves included) may not have realized that by asserting the value of biodiversity conservation in either general or specific terms, they are stating a “normative postulate:” a value judgment taken to be true and foundational to further thinking. These assumptions are based on some theory of value and ethical reasoning, but often one that has not been made fully explicit. Consequently, many theories and metrics in empirical scientific research may be founded on hidden normative postulates of which practitioners are often unaware. We consider five cases where this may be the case: local vs. global diversity, prioritization based on evolutionary distinctness, species concepts, extinction by hybridization, and non-native species. Conflicts over the interpretation of data driven by different parties holding to different conceptions of ethics and philosophy are possible, with little guidance on how they can best be adjudicated. To the extent this is true, there exists a “normative postulate problem” for biodiversity researchers.