Table 1.
Characteristics of two major classes of phylogeographic analysis. Although ‘exploratory’ and ‘model-driven’ analyses are not mutually exclusive, the dichotomy can serve as a conceptual framework.
| Characteristic |
Class of analysis |
|
|---|---|---|
| Exploratory | Model-driven | |
| Level of Parameterization | Low | High |
| Reliance on a priori assumptions | Low | High |
| Multiple events or population processesa | No | Yes |
| Coverage of total ‘scenario space’ | Broad | Narrow |
| Permits unexpected discoveries | Yes | Limited |
| Accommodates stochasticity | Limited | Yes |
| Statistical discrimination among alternatives | Limited | Yes |
| Framework for comparisons across species | Qualitative | Quantitative |
a
NCPA is considered ‘exploratory’ here and is unique in its ability to separate multiple temporally overlying events and processes. Conversely, several model-driven methods explicitly consider temporally sequential events or processes (e.g., IM, simulations within population trees; Sections 4.3 and 4.4).