The problem of baselining

Abstract When scientists study a changing system, how do they distinguish trivial changes from significant ones? What is the ‘normal’ state of the system in question, from which changes are to be discerned? In ecology, this question arises in the context of producing ‘baselines’ for an ecosystem, and is associated with the related problem of ‘shifting baseline syndrome’. Here, I explore the process of baseline production (‘baselining’), with the hope of both clarifying some issues surrounding baselines in ecology, and also showing the benefits of thinking about baselines elsewhere in the life sciences. More specifically, I show that baselining typically involves idealisation (which has consequences for debates about the role of the past in producing baselines); that shifting baseline syndrome is derivative of the broader questions of when, how, and why to re-baseline a study system; that thinking in terms of baselines may help sidestep debates about ‘normality’ across the life sciences; and that changes in a target system may warrant changes to the system used to study it (meaning that anthropogenic activity may trigger re-baselining debates in areas of science beyond ecology).