Revisiting Measuring the Evolution of N-dimensional Environmental Niches: The Need for a Solid Conceptual Basis for New Methodologies

The paper titled “Measuring the evolution of n-dimensional environmental niches” recently published by Sharma et al. (2024) presents a methodology that claims to measure evolution of ecological niches. Here, we argue that flaws in the conceptual framework behind this methodology, ignoring the distinction between fundamental and realized niches of species, leads to mis-estimations of amounts of evolutionary change in environmental tolerances of lineages. After a conceptual review, using one of the Sharma et al. study cases, we show the importance of considering different sources of uncertainty in reconstructing ecological niches, including consideration of historically accessible areas (M) for species and sampling biases in occurrence data, which also impact niche estimations. The Sharma et al. focus on the realized niche, rather than observable parts of the fundamental niche, leads to mis-interpretation of non-evolved consequences of the environmental variation manifested across M as niche evolution. Reconstructing any niche other than the fundamental niche results in overestimation of niche evolution.