Occurrence data uncover patterns of allopatric divergence and interspecies interactions in the evolutionary history of lizards.

As shown from several long-term and time-intensive studies, closely related, sympatric species can impose strong selection on one another, leading to dramatic examples of phenotypic evolution. Here, we use occurrence data to identify clusters of sympatric lizard species and to test whether species tend to coexist with other species that differ in body size, as we would expect when there is competition between sympatric congeners. We found that species can be grouped into 16 unique bioregions.