Taxonomic inflation: species concept or historical geopolitical bias?

In a recent article in TREE [1], Isaac et al. examine taxonomic inflation, which they describe as ‘where known subspecies are raised to species as a result in a change of species concept’. Their argument is that more species are erected under the phylogenetic species concept than under the biological species concept. However, we argue that this inflation is due to a historical geopolitical bias affecting current predictions of expected genetic diversity within species.