Estimating the number of species with CatchAll.

In many situations we are faced with the need to estimate the number of classes in a population from observed count data: this arises not only in biology, where we are interested in the number of taxa such as species, but also in many other fields such as public health, criminal justice, software engineering, etc. This problem has a rich history in theoretical statistics, dating back at least to 1943, and many approaches have been proposed and studied. However, to date only one approach has been implemented in readily available software, namely a relatively simple nonparametric method which, while straightforward to program, is not flexible and can be prone to information loss. Here we present CatchAll, a new, platform-independent, user-friendly, computationally optimized software package which calculates a powerful and flexible suite of parametric models (based on current statistical research) in addition to all existing nonparametric procedures. We briefly describe the software and its mathematical underpinnings (which are treated in depth elsewhere), and we work through an applied example from microbial ecology in detail.