Meeting Abstract

56.5  Tuesday, Jan. 6  The Measurement and Interpretation of Phylogenetic Signal REVELL, Liam J.*; COLLAR, David C.; HARMON, Luke J.; Harvard University; Harvard University; University of Idaho lrevell@fas.harvard.edu

Recently, biologists have been inclined to make process-oriented inferences from measures of phylogenetic signal, defined as the pattern of statistical dependence among the observations for species related by a phylogenetic tree. However, the relationship between the evolutionary process, the rate of evolution, and the phylogenetic signal for continuously distributed characters has never been rigorously examined. We used individual-based phylogenetic simulations of a variety of evolutionary scenarios to examine the relationship between phylogenetic signal and evolutionary process. Under genetic drift we found no relationship between the rate of evolution and phylogenetic signal. For other evolutionary processes such as functional constraint, fluctuating selection, niche conservatism, and various types of evolutionary heterogeneity, the relationship between evolutionary process, rate, and phylogenetic signal is more complex. Thus, we recommend against the over-interpretation of phylogenetic signal in empirical studies.