Data from: Phylogeographic estimation and simulation of global diffusive dispersal

The analysis of time-resolved phylogenies (timetrees) and geographic
location data allows estimation of dispersal rates, for example for
invasive species and infectious diseases. Many estimation methods are
based on the Brownian Motion model for diffusive dispersal on a
2-dimensional plane, however the accuracy of these methods deteriorates
substantially when dispersal occurs at global scales because Spherical
Brownian Motion (SBM) differs from planar Brownian Motion. No statistical
method exists for estimating SBM diffusion coefficients from a given
timetree and tip coordinates, and no method exists for simulating SBM
along a given timetree. Here I present new methods for simulating SBM
along a given timetree, and for estimating SBM diffusivity from a given
timetree and tip coordinates using a modification of Felsenstein's
independent contrasts and maximum-likelihood. My simulation and fitting
methods can accommodate arbitrary time-dependent diffusivities and scale
efficiently to trees with millions of tips, thus enabling new analyses
even in cases where planar BM would be a sufficient approximation. I
demonstrate these methods using a timetree of marine and terrestrial
Cyanobacterial genomes, as well as timetrees of two globally circulating
Influenza B clades. My methods are implemented in the R package
"castor."