Dismantling the Mantel tests

1. The simple and partialMantel tests are routinely used in many areas of evolutionary biology to assess the significance of the association between two ormorematrices of distances relative to the same pairs of individuals or demes. Partial Mantel tests rather than simple Mantel tests are widely used to assess the relationship between two variables displaying some form of structure. 2.

We show that contrary to a widely shared belief, partialMantel tests are not valid in this case, and their bias remains close to that of the simpleMantel test. 3. We confirm that strong biases are expected under a sampling design and spatial correlation parameter drawn from an actual study. 4. TheMantel tests should not be used in case autocorrelation is suspected in both variables compared under the null hypothesis.We outline alternative strategies.

The R code used for our computer simulations is distributed as supportingmaterial.