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paleoTS (version 0.3-1)

paleoTS-package: Analysis of evoltuionary time-series

Description

This package includes a variety of functions useful for analyzing evoltuionary time-series, particularly for paleontological data. The functions are useful for analyzing sequences in terms of statistical models, with three models implemented: directional evolution (modeled as a general random walk), unbiased random walks, and stasis. These analyses are outlined in Hunt (2006). Two different parameterizations can be used to fit these models, the default (based on ancestor-descendant differences), and a joint method, which uses all sample means jointly to fit the model. The joint parameterization can also be used to fit an Ornstein-Uhlenbeck model, which is intermediate between a random walk and stasis (see Hunt et al., 2008). Starting with v0.3-1, functions are included that allow fitting of models of punctuated evolution, and other models in which evolutionary dynamics change throughout an observed evolutionary sequence (see Hunt 2008).

Arguments

Details

ll{ Package: paleoTS Type: Package Version: 0.3-1 Date: 2008-01-16 License: GPL 2 }

References

Hunt, G. 2006. Fitting and comparing models of phyletic evolution: random walks and beyond. Paleobiology32:578--601. Hunt, G., M. Bell & M. Travis. 2008. Evolution towards a new adaptive optimum: phenotypic evolution in a fossil stickleback lineage. Evolution 62:700-710. Hunt, G. 2008. Gradual or pulsed evolution: when should punctuational explanations be preferred? Paleobiology34:In press.

Examples

Run this code
x <- sim.GRW(ns=30, ms=0, vs=0.3)	# simulate unbiased random walk
 fit3models(x)		# compare fits of directional, random walk, and stasis models

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