A robust new metric of phenotypic distance to estimate and compare multiple trait differences among populations  

作　　者：Rebecca SAFRAN Samuel FLAXMAN Michael KOPP Darren E. IRWIN Derek BRIGGS Matthew R. EVANS W. Chris FUNK David A. GRAY Eileen A. HEBETS Nathalie SEDDON Elizabeth SCORDATO Laurel B. SYMES Joseph A. TOBIAS David P. L. TOEWS J. Albert C. UY 

机构地区：[1]Department of Ecology and Evolutionary Biology, University of Colorado, Boulder CO 80309, U.S.A. [2]Mathematics and B iosciences Group, Faculty of Mathematics, University of Vienna, A-1090 Vienna, Austria Current address Evolutionary Biology and Modeling Group, Faculty of Sciences, Aix-Marseille University, 13331 Marseille, France. [3]Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, BC, Canada, V6T 1Z4. [4]Research ＆ Evaluation Methodology, School of Education, University of Colorado, Boulder, CO 80309, U.S.A. [5]School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS [6]Department of Biology, Colorado State University, Fort Collins, CO 80523, U.S.A. [7]Department of Biology, California State University, Northridge, CA 91330, U.S.A. [8]School of Biological Sciences, University of Nebraska, Lincoln, NE 68588, U.S.A. [9]Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK [10]Committee on Evolutionary Biology, The University of Chicago, Chicago, IL, 60637,U.S.A. [11]Department of Biology, Dartmouth College, Hanover, NH 03755, U.S.A. [12]Department of Biology, University of Miami, Coral Gables, FL 33146, U.S.A.

出　　处：《Current Zoology》2012年第3期426-439,共14页动物学报（英文版）

基　　金：Acknowlegements We thank Matthew Arnegard, Carlos Botero, Tamra Mendelson, Rafael Rodriqu6z and Sander van Doom for excellent discussions about the need for a new phenotypic distance metric and Maria Servedio for the invitation and encouragement to formalize our ideas. This research was supported as part of the Sexual Selection and Speciation working group by the National Evolutionary Synthesis Center （NESCent）, NSF #EF-0905606. RJS and SMF were supported by the University of Colorado and National Science Founda- tion grant IOS-0717421to RJS. MK was supported by a grant from the Vienna Science and Technology Fund （WWTF） to the Mathematics and Biosciences Group at the University of Vienna. EAH thanks Mitch Bern for use of his Master＇s thesis data and was supported by the National Science Foundation grant lOS - 0643179. DEI and DPLT were supported by the Natural Sciences and Engineering Research Council of Can- ada （Discovery Grants 311931-2005 and 311931-2010 to DEI, CGS-D to DPLT）. NS and JAT were supported by the Royal Society, British Ecological Society and John Fell Fund （Ox- ford University）. ES supported by NSF-DDIG the American Ornithologists Union, the University of Chicago, and the American Philosophical Society Lewis and Clark award. JACU was funded by National Science Foundation grant lOS 0306175.

摘　　要：Whereas a rich literature exists for estimating population genetic divergence, metrics of phenotypic trait divergence are lacking, particularly for comparing multiple traits among three or more populations. Here, we review and analyze via simula- tion Hedges＇ g, a widely used parametric estimate of effect size. Our analyses indicate that g is sensitive to a combination of unequal trait variances and unequal sample sizes among populations and to changes in the scale of measurement. We then go on to derive and explain a new, non-parametric distance measure, ＇Aft＇, which is caiculated based upon a joint cumulative distribution function （CDF） from all populations under study. More precisely, distances are measured in terms of the percentiles in this CDF at which each population＇s median lies. Ap combines many desirable features of other distance metrics into a single metric; namely, compared to other metrics, p is relatively insensitive to unequal variances and sample sizes among the populations sam- pied. Furthermore, a key feature of Ap--and our main motivation for developing it--is that it easily accommodates simultaneous comparisons of any number of traits across any number of populations. To exemplify its utility, we employ Ap to address a ques- tion related to the role of sexual selection in speciation： are sexual signals more divergent than ecological traits in closely related taxa？ Using traits of known function in closely related populations, we show that traits predictive of reproductive performance are indeed, more divergent and more sexually dimorphic than traits related to ecological adaptation [Current Zoology 58 （3）： 426-439 2012].

关 键 词：Effect size Phenotype divergence Sexual dimorphism Sexual selection SPECIATION 

分 类 号：S154.381[农业科学—土壤学] TN957.52[农业科学—农业基础科学]