Dear colleagues, I got a philosophical/methodological/practical question.
I have a continuous dependent variable (e.g. range size) and a few "independent" variables (e.g. body mass, encephalization ratio), and I want to test how the rate of evolution of the dependent variable is affected by the independent variables. The PCMs that I'm familiar with cannot be used to answer this question, because they usually try to predict the dependent variable based on the independent variables (e.g. PGLM) instead of looking at the rates of evolution. The whole thing gets tricky if one decides to deal with the rates of evolution of the indepentent variables as well (or not). I guess one possibility would be to use standardized independent contrasts (as in Garland 1992) for the estimation of rates. But I'm not sure how to try to predict the *rate* of evolution of range size from the values of the "independent" variables (and not their own rates, which is what I guess I'd get if I transformed all variables into standardized contrasts). Any thoughts? John _______________________________________________ R-sig-phylo mailing list - [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-phylo Searchable archive at http://www.mail-archive.com/[email protected]/
