Hi Karla, Looks like I missed out on an interesting conversation. If you are interested in seeing an application of some of the methods/issues discussed, we recently had a paper comparing rates of evolution among different color traits in birds (http://onlinelibrary.wiley.com/doi/10.1111/evo.12575/abstract). Briefly, we fit various multivariate models in ouch and assessed whether diagonal elements of sigma2/alpha matrices differed from each other using parametric bootstrapping. I’d be happy to share the R code with you if it helps.
Chad — Chad Eliason Postdoctoral Fellow, Clarke lab Department of Geological Science University of Texas at Austin > On Jul 17, 2015, at 9:17 AM, Karla Shikev <[email protected]> wrote: > > Thank you all for the valuable input! > > cheers! > > Karla > > On Fri, Jul 17, 2015 at 12:17 AM, Giulio V. Dalla Riva <[email protected]> > wrote: > >> P.S. Rumbling on that: a proper answer, however, in a phylogenetic >> scenario would also require to try and estimate the evolution of the >> intralineage trait variance (an ancestral state reconstruction of the trait >> mean and variance) as the hypothesis that it has been constant during long >> times seems rather weak. In that case one should probably try to give a >> proper definition of "phylogenetic haldanes", i.e., averaging between the >> variance at start and endpoint of each branch... Or am I completely wrong? >> >> Giulio Valentino Dalla Riva >> PhD candidate @ Biomathematics Research Centre >> University of Canterbury >> Christchurch, NZ >> Phone: +64 3642987 ext 4869 >> >>> On 17/07/2015, at 3:41 am, Theodore Garland Jr <[email protected]> >> wrote: >>> >>> If everything is log-transformed then the variance of phylogenetically >> independent contrasts or, equivalently, the MSE (if I remember correctly) >> from a PGLS analysis is directly related to the rate of trait evolution. >> I'm not sure of the best way to test for statistical differences among >> traits, but I am sure you could do this with simulations. >>> >>> Cheers, >>> Ted >>> >>> Theodore Garland, Jr., Professor >>> Department of Biology >>> University of California, Riverside >>> Riverside, CA 92521 >>> Office Phone: (951) 827-3524 >>> Facsimile: (951) 827-4286 (not confidential) >>> Email: [email protected] >>> http://www.biology.ucr.edu/people/faculty/Garland.html >>> http://scholar.google.com/citations?hl=en&user=iSSbrhwAAAAJ >>> >>> Director, UCR Institute for the Development of Educational Applications >>> >>> Editor in Chief, Physiological and Biochemical Zoology >>> >>> Fail Lab: Episode One >>> http://testtube.com/faillab/zoochosis-episode-one-evolution >>> http://www.youtube.com/watch?v=c0msBWyTzU0 >>> >>> ________________________________________ >>> From: R-sig-phylo [[email protected]] on behalf of >> Karla Shikev [[email protected]] >>> Sent: Thursday, July 16, 2015 2:13 PM >>> To: [email protected] >>> Subject: [R-sig-phylo] testing for variation in rates of evolution >> among traits >>> >>> Hi there, >>> >>> I've come across several methods to test for differences in the rate of >>> evolution among branches in a tree, but I can't find methods to test for >>> differences in rates of evolution of different traits on the same species >>> (ex. if wing size evolution is faster than than overall body size >>> evolution). Any suggestions? >>> >>> Thanks! >>> >>> Karla >>> >>> [[alternative HTML version deleted]] >>> >>> _______________________________________________ >>> 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]/ >>> >>> _______________________________________________ >>> 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]/ >> > > [[alternative HTML version deleted]] > > _______________________________________________ > 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]/ _______________________________________________ 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]/
