Manuscript Click here to download Manuscript: SmithGoldberg060115.docx Smith and Goldberg 2015 Tempo and mode of color evolution 1 Tempo and mode of flower color evolution1 Stacey D. Smith2,4 and Emma E. Goldberg3 2Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA 3Department of Ecology, Evolution & Behavior, University of Minnesota, St Paul, MN 55105, USA 1Manuscript received __________; revision accepted ___________ The authors thank S. Otto for advice, and two anonymous reviewers for helpful comments on the manuscript. This publication was supported in part by funds from the National Science Foundation (DEB 1355518 and 1413855 to SDS). 4Email for correspondence:
[email protected] Smith and Goldberg 2015 Tempo and mode of color evolution 2 ABSTRACT Premise of the Study: Flower color is one of the best-studied floral traits in terms of its genetic basis and ecological significance, yet few studies have examined the processes that shape its evolution across deep timescales. Advances in comparative methods along with larger phylogenies for floral radiations offer new opportunities for investigating the macroevolution of flower color. Methods: We examine the tempo and mode of flower color evolution in four clades (Antirrhineae, Iochrominae, Loeselieae, Quamoclit) using models that incorporate trait transitions and lineage diversification. Focusing on floral anthocyanin pigmentation, we estimate rates of gain and loss of pigmentation and test whether these changes occur predominantly through anagenesis or cladogenesis. Key Results: We found that the tempo of pigment gains and losses varies significantly across the clades and that the rates of change are often asymmetrical, favoring gains over losses.