[Taxacom] Geophylogenies

[Kidd, David M]

A geophylogeny is simply a data structure that can represent historical biogeographic (including phylogeographic) pattern, or hypothesese, in a spatially explicit manner. Such a data structure facilitates data exchange, the visual comparison of models with external (e.g. geological) data, and their analysis within GIS. How geophylogenies are constructed will vary. Is the aim exploration of extant pattern or a historical recontruction?
I aim to write parsers for the various historical biogeographical algorithms (La Grange, DIVA etc), but time has prevented this so far. If anyone interested in implementing some please contact me.

The range of information and algorithms available also affects what analyses are possible. For example, I am exploring relationships between freshwater fish phylogenies and the rise of the TransMexican Volcanic Belt. DIVA or LaGrange cannot be applied to this system as we only have very fragmented knowledge of change in the drainage network, making the construction of area connectivity models impossible. In addition, DIVA and La Grange are severly limited by the number of areas that can be coded, and their underlying biogeographic models do not allow the modelling of the directional exchange of a basin fragments with an adjacent basin through river piracy. I have, however, just implemented an algorithm in which nodes are located on the basis of overlap and disjunction between sister clade ranges. This approach is helping us to identify the hydrological events urderlying current pattern including previously undocumented river piracy events and, I believe, a minor radiation in a palaeolake.

While historical biogeographers should strive for rigour and quantification, they must also recognise that historical science often has more in common with Sherlock Holmes than Issac Newton (http://spot.colorado.edu/~cleland/articles/Cleland.PS.Pdf)



David M. Kidd

Research Associate
Center for Population Biology
Silwood Park Campus
Imperial College London
0207 594 2470