Phylogenetic Signal, Evolutionary Process, and Rate

Abstract

A recent advance in the phylogenetic comparative analysis of continuous traits has been explicit, model-based measurement of "phylogenetic signal" in data sets composed of observations collected from species related by a phylogenetic tree. Phylogenetic signal is a measure of the statistical dependence among species' trait values due to their phylogenetic relationships. Although phylogenetic signal is a measure of pattern (statistical dependence), there has nonetheless been a widespread propensity in the literature to attribute this pattern to aspects of the evolutionary process or rate. This may be due, in part, to the perception that high evolutionary rate necessarily results in low phylogenetic signal; and, conversely, that low evolutionary rate or stabilizing selection results in high phylogenetic signal (due to the resulting high resemblance between related species). In this study, we use individual-based numerical simulations on stochastic phylogenetic trees to clarify the relationship between phylogenetic signal, rate, and evolutionary process. Under the simplest model for quantitative trait evolution, homogeneous rate genetic drift, there is no relation between evolutionary rate and phylogenetic signal. For other circumstances, such as functional constraint, fluctuating selection, niche conservatism, and evolutionary heterogeneity, the relationship between process, rate, and phylogenetic signal is complex. For these reasons, we recommend against interpretations of evolutionary process or rate based on estimates of phylogenetic signal.

Predicting microbial traits with phylogenies

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Phylogenetic signal in primate behaviour, ecology and life history

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Are Voluntary Wheel Running and Open-Field Behavior Correlated in Mice? Different Answers from Comparative and Artificial Selection Approaches

“…Phylogenetic signal is the tendency for related species (or populations) to resemble each other, and its presence has implications for understanding how traits evolve and how comparative data are best analyzed in the context of a phylogeny (Blomberg et al 2003;Revell et al 2008). The presence of phylogenetic signal was tested as described in Blomberg et al (2003), with a randomization procedure for the mean-squared error (MSE) using MATLAB program PHYSIG_LL.m.…”