Correlated evolution and independent contrasts

Identical inferences about correlated evolution arise from ancestral state reconstruction and independent contrasts.

Inferences about the evolution of continuous traits based on reconstruction of ancestral states have often been considered more error-prone than analysis of independent contrasts. Here we show that both methods in fact yield identical estimators for the correlation coefficient and regression gradient of correlated traits, indicating that reconstructed ancestral states are a valid source of info...

Rate tests for phenotypic evolution using phylogenetically independent contrasts.

Most studies of evolutionary rates, except those concerning laboratory populations, use data from fossils to measure amounts of change occurring over time (e.g., Raup and Crick 1981; Cracraft 1984; Stanley 1985; Futuyma 1986; Bookstein 1987, 1988, 1989; Campbell and Day 1987; Gingerich 1987; Rosenzweig et al. 1987; Forey 1988; MacFadden 1988; McNamara 1990; Taylor and Larwood 1990; Fenster and ...

Independent contrasts and regression through the origin.

Following the pioneering work of Felsenstein and Garland, phylogeneticists have been using regression through the origin to analyze comparative data using independent contrasts. The reason why regression through the origin must be used with such data was revisited. The demonstration led to the formulation of a permutation test for the coefficient of determination and the regression coefficient ...

Nonlinear relationships and phylogenetically independent contrasts.

The method of phylogenetically independent contrasts is commonly used for exploring cross-taxon relationships between traits. Here we show that this phylogenetic comparative method (PCM) can fail to detect correlated evolution when the underlying relationship between traits is nonlinear. Simulations indicate that statistical power can be dramatically reduced when independent contrasts analysis ...

Contrasts, Independent Component Analysis, and Blind Deconvolution