31 Oct 2004 12:34 AR AR229-ES35-14.tex AR229-ES35-14.sgm LaTeX2e(2002/01/18) P1: GJB 10.1146/annurev.ecolsys.34.011802.132347 Annu. Rev. Ecol. Evol. Syst. 2004. 35:375–403 doi: 10.1146/annurev.ecolsys.34.011802.132347 Copyright c 2004 by Annual Reviews. All rights reserved First published online as a Review in Advance on July 26, 2004 POLLINATION SYNDROMES AND FLORAL SPECIALIZATION Charles B. Fenster,1 W. Scott Armbruster,2 Paul Wilson,3 Michele R. Dudash,1 and James D. Thomson4 1Department of Biology, University of Maryland, College Park, Maryland 20742; email:
[email protected];
[email protected] 2School of Biological Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom; Department of Biology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway; Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska 99775; email:
[email protected] 3Department of Biology, California State University, Northridge, California 91330-8303; email:
[email protected] 4Department of Zoology, University of Toronto, Toronto, ON M5S 3G5; email:
[email protected] KeyWords floral evolution, mutualism, plant-animal interaction, pollinator, pollination ■ Abstract Floral evolution has often been associated with differences in pollina- tion syndromes. Recently, this conceptual structure has been criticized on the grounds that flowers attract a broader spectrum of visitors than one might expect based on their syndromes and that flowers often diverge without excluding one type of pollinator in favorofanother. Despite these criticisms, we show that pollination syndromes provide great utility in understanding the mechanisms of floral diversification. Our conclusions are based on the importance of organizing pollinators into functional groups according to presumed similarities in the selection pressures they exert.