paleoTSalt-package {paleoTSalt}R Documentation

Fitting models of evolution to paleontological time-series of phenotypic data

Description

This package facilitates analysis of paleontological sequences of trait values from an evolving lineage. Functions are provided to fit, using maximum likelihood, evolutionary models including unbiased random walks, directional evolution, stasis and OU (Orstein-Uhlenbeck) models. This package has a similar purpose as the paleoTS package, but employs a different parameterization of evolutionary models.

Details

Package: paleoTSalt
Type: Package
Version: 0.1-1
Date: 2007-10-22
License: GPL 3 or newer

Author(s)

Gene Hunt, hunte@si.edu

References

Hunt, G. 2006. Fitting and comparing models of phyletic evolution: random walks and beyond. Paleobiology 32:578–601.

See Also

paleoTS-package

Examples

data(dorsal.spines)

# get subset of samples from invading lineage (tt>=4.5 Kyr), only those with nn>=5
ok<- dorsal.spines$tt >= 4.5 & dorsal.spines$nn >=5
ds2<- sub.paleoTS(dorsal.spines, ok=ok)

# convert time scale to generations (500 gen per Kyr)
ds2$tt<- ds2$tt*(1000/2)        
plot(ds2, pool=TRUE)

# compare URW (drift) and OU (adaptive) models
m.urw<- opt.alt.URW(ds2, pool=TRUE)
m.ou<- opt.alt.OU(ds2, pool=TRUE)
cat ("Model","logL", "AICc\n", sep="\t")
cat ("URW", round(m.urw$val, 2), round(m.urw$AICc, 2), sep="\t")
cat ("\nOU", round(m.ou$val, 2), round(m.ou$AICc, 2), sep="\t")
add.OU.curves(m.ou, ds2, col="grey")

[Package paleoTSalt version 0.1-1 Index]