Additive partitioning of a beta diversity index is controversial

A recent study (1) reports the spatial clustering patterns of the global distribution of human infectious diseases. However, there are some controversial issues that arise from the beta diversity partitioning method used in the paper. To further debate these issues, we follow the same notations in the paper (1) by writing the Sorensen beta diversity index as βsor=(b+c)/(2a+b+c)βsor=(b+c)/(2a+b+c). Here, a is the number of diseases common to a pair of sites, whereas b and c are the number of diseases that are unique to each of the two sites being compared, respectively. Murray et al. (1 …