code and files for doing SDM with Maxent/dismo etc. in R for western spadefoot; evolved out of eeb234 final project

Started out as a final project in a graduate-level practical computing for evolutionary biologists course.

It has mostly served as an elaborate learning process in R, going from raw GBIF localities to cleaning them up, subsampling, downloading bioclim layers, etc. and running Maxent via the dismo package in R; did SDM with Maxent for current conditions, LGM, and future with different projections. Throughout the code I have a lot of comments noting missteps or papers with abundant info on the nature of SDM's, especially with Maxent.

This is ongoing. Other steps will entail model evaluation (package ENMeval LIG modeling, more future climate scenarios, different spadefoots in the same genus, incorporation of phylogenies/genetic data in general