What is the mid-domain effect (MDE)?
The mid-domain effect is the increasing overlap of species ranges towards the center of a shared, bounded domain due to geometric boundary constraints in relation to the distribution of species’ range sizes, producing a peak or plateau of species richness towards the center of the domain. Domains may be spatial, temporal, or funcitional. The MDE References page at this site provides a guide to the growing literature on MDE. Major Features of RangeModel • Easy-to-use, graphical interface with button and menu-driven commands. • Tools for exploring the role of several theoretical range size frequency distributions (RSFDs), with or without upper and lower ranges size thresholds. • Options to display and export realized range-size frequency distributions, realized midpoint distributions, and Stevens’ Rapoport plots. • Tools for importing and visualizing empirical richness patterns, based on midpoint-range data. • Tools for randomizing the placement of empirical ranges (or any RSFDs input by
