Addressing common pitfalls does not provide more support to geographical and ecological abundant‐centre hypotheses
A long‐standing hypothesis in biogeography is that a species’ abundance is highest at the centre of its geographical or environmental space and decreases toward the edges. Several studies tested this hypothesis and provided mixed results and overall weak support to the theory. Most studies, however, are affected by several limitations related to the sample size, the comparability among abundance measures, the definition of species geographic range and corresponding environmental space, and the proxy variables used to represent centrality/marginality gradients.