Department of Botany & the U.S. National Herbarium The Plant Press New Series - Vol. 11 - No. 1 January-March 2008 Botany Profile Humming to the Tune of Coevolution By W. John Kress and Ethan J. Temeles major goal of systematic, evolu- system to test Thompson’s theory. Both bills of males, whereas on Dominica the tionary, and ecological studies is the pollinators and the plants exhibit char- male-pollinated H. caribaea develops a A to understand the processes that acter polymorphisms, which can be read- second morph with longer, curved flow- shape adaptations of organisms to their ily linked to fitness measures, throughout ers matching the bills of females. The environment. One approach towards this their ranges. Over the last several years nectar rewards of all Heliconia morphs goal is to use patterns of morphological and probably for a number of years to on both islands are consistent with each variation among closely related species come we plan to study co-adaptations sex’s choice for the morph correspond- to make inferences about the kinds of in this plant-hummingbird association ing to its bill morphology and energy ecological processes, such as competi- through extensive observations of both requirements, supporting the hypotheses tion, predation, parasitism, or mutualism, floral and sexual dimorphisms across the of ecological causation of sexual dimor- through which these characteristics have island archipelago in the Eastern Carib- phism and co-adaptation. evolved. This type of study traces back to bean. Our work started nearly a decade ago Charles Darwin and his classic observa- when Ethan Temeles initiated studies tions in the Galapagos Islands of beak he focal system of this research of the purple-throated carib humming- variation and food types among species involves the purple-throated carib bird, Eulampis jugularis, on the island of ground finches in the genus Geospiza. Thummingbird, Eulampis jugularis, of St. Lucia. The males and females are Since Darwin’s time, interactions and its Heliconia food plants, considered identical in plumage, but display some between flowering plants and their polli- one of the strongest examples of ecologi- of the most extreme sexual dimorphisms nators have provided model examples of cal causation of sexual dimorphism to date of any hummingbird species. First, bills hypothesized feeding adaptations, species and a well-documented plant-pollinator of males average 24.8 mm in length, specialization, and coevolution. How- mutualism. Many biology textbooks note whereas bills of females average 29 mm ever, some investigations suggest that that flowers pollinated by hummingbirds in length, a difference of 15 percent. such interspecific interactions are seldom have long, tubular corollas matching the Moreover, bills of males are relatively constant throughout a species’ range and size and shape of the birds’ beaks. Darwin straight, curving downwards at a 15 that populations differ in the traits shaped himself stated that bills of hummingbirds degree angle, whereas bills of females by the interaction. These observations are specially adapted to the various kinds are highly curved, curving downwards at have resulted in the John Thompson’s of flowers they visit. a 30 degree angle. proposed “Geographic Mosaic Theory Our work has provided evidence for These differences in bill morphol- of Coevolution.” Accordingly, studies of co-adaptation by demonstrating that the ogy were associated with differences in co-adaptation between species require an purple-throated carib hummingbird is the the use of the two Heliconia species on analysis of populations across the broad primary pollinator of H. caribaea and H. the island. Males were associated with a geographic distribution of the species. bihai, with flowers of the former cor- red-bracted morph of H. caribaea, which Some populations across this geographic responding to the short, straight bills of they defended against other males and landscape are hotspots of reciprocal males (the larger sex) and flowers of the females. In contrast, females intruded selection and others are coldspots with latter to the longer, curved bills of females. onto male territories to feed and also fed little coevolution. Further evidence for co-adaptation comes at undefended patches of H. caribaea, We have recently described an from a reversal in the floral dimorphism of but more importantly they were the interaction between a plant and its hum- the Heliconia food plants on two islands: predominant visitor to the other Helico- mingbird pollinator found in the Eastern on St. Lucia, the female-pollinated H. nia, a green-bracted morph of H. bihai. Caribbean that provides an ideal tropical bihai develops a second morph with shorter, straighter flowers matching the Continued on page 9 Travel Pedro Acevedo traveled to Bronx, Vicki Funk traveled to Philadelphia, non-profit organization that is web-hosting New York (12/9) to attend a meeting of the Pennsylvania (12/13) to serve on the the Latin American Plants Initiative. Caribbean Flora initiative sponsored by search committee for a new Curator of Alain Touwaide and Emanuela the New York Botanic Garden. Botany at the Academy of Natural Sci- Appetiti traveled to Italy (10/2 – 10/7) to Walter Adey traveled to Philadelphia, ences of Philadelphia. participate in the meeting of the Inter- Pennsylvania (10/10) to give a technical Carol Kelloff traveled to George- national Association for the History of presentation of the Algal Turf Scrubber town, Guyana (10/8 – 10/19) with Karen Nephrology in Palermo, to work at the (ATS) Energy Project at the Region 3 Redden (George Washington University National Library in Rome, to present three EPA; to Kennett Square, Pennsylvania postdoctoral fellow) to meet with staff at seminars in Naples, and to present a paper (12/2 – 12/4) to give a technical presenta- the University of Guyana and the Centre at the Meeting of the International Society tion to Exelon officials; to Blacksburg, for the Study of Biological Diversity. for the History of Medicine in Figline Virginia (12/5 – 12/7) to give an invited W. John Kress traveled to Cambridge, Valdarno; to Siena, Italy (10/12 – 10/29) presentation at Virginia Tech; and to Massachusetts (10/4 – 10/10) to attend to attend the 100th Conference of the Ital- Conowingo Dam, Maryland (12/12) to the Island Biogeography Symposium at ian Society for the History of Medicine; review test plans with engineers and Harvard University and to work with Ted and to deliver a paper at an international officials and to make a presentation to the Fleming on their vertebrate pollination and conference organized on the occasion of University of Maryland, Department of dispersal book; to Millersville, Pennsylva- the 750th anniversary of Pietro D’Abano’s Natural Resources. nia (11/7) to give a lecture on tropical pol- birthday in Abano Terme; and to Venice, Laurence Dorr traveled to Cambridge, lination systems at Millersville University; Italy (11/28 – 12/9), to work at the Marci- Massachusetts (11/1 – 11/5) to pres- and to Panama City, Panama (12/4 – 12/7) ana National Library. ent a talk to the New England Botanical with post-doc David Erickson to meet Warren Wagner traveled to St. Louis, Club on Malagasy plants that have been with STRI Director Biff Bermingham Missouri (10/06 – 10/15) to attend the introduced into cultivation, and to exam- and Oris Sanjur for discussions on DNA board meeting of the National Tropical ine Malvaceae in the Harvard University barcoding the woody plants in the Forest Botanical Garden, gave a presentation on herbaria. Dynamics Plot on Barro Colorado Island. the McBryde Pacific Botany Program, and Robert Faden traveled to St. Louis, Mark and Diane Littler traveled to attended the annual Systematics Sympo- Missouri (12/2 – 12/5) to attend a meeting South Florida (12/25 – 2/15) to conduct sium of the Missouri Botanical Garden; on a proposed Cultivated Flora of North field research on marine algae and sea- and to St. Louis, Missouri (10/30 – 11/2) America at the Missouri Botanical Garden, grasses based at the Smithsonian Marine to attend the first working group of the and to conduct herbarium work on African Station, Ft. Pierce. Encyclopedia of Life and contribute to the Commelinaceae. Rusty Russell traveled to Panama species web pages for plants at the Mis- City, Panama (10/22 – 10/26) to take part souri Botanical Garden. in a meeting of the Mellon-funded Latin Kenneth Wurdack traveled to Cam- The Plant Press American Plants Initiative at STRI; and bridge, Massachusetts (12/14 – 12/17) to to Princeton, New Jersey (11/20) with conduct research at Harvard University. New Series - Vol. 11 - No. 1 Christine Allocca to meet with Aluka, a Chair of Botany Visitors Warren L. Wagner ([email protected]) Ki-Oug Yoo, Kangwon National Uni- Hongli Tian, Beijing Institute of Botany, versity, Chuncheon, South Korea; Cory- China; Nelumbo (Nelumbonaceae) (4/25- EDITORIAL STAFF loideae and Vitaceae (12/12/06-12/11/07). 10/24). Editor Lei Xie, Chinese Academy of Sciences; Yunjuan Zuo, Beijing Institute of Botany, Gary Krupnick Clematis (Ranunculaceae), Circaea and China; Panax (Araliaceae) (5/7/07- ([email protected]) Fuchsia (Onagraceae) (1/1/07-12/31/08). 5/6/08). News Contacts MaryAnn Apicelli, Robert Faden, Ellen Tieyao Tu, Kunming Institute of Botany, Melissa Luckow, Cornell University; Farr, Shirley Maina, Rusty Russell, Alice China; Nolana (Solanaceae) (1/18/07- Leguminosae (7/16/07-6/30/08). Tangerini, and Elizabeth Zimmer 1/17/08). Tracey Parker, Independent researcher, The Plant Press is a quarterly publication Ling Zhang, Xishuangbanna Tropical Managua, Nicaragua; Central American provided free of charge. If you would like to be added to the mailing list, please contact Dr. Gary Botanic Garden, Chinese Academy of plants (9/18-10/2). Krupnick at: Department of Botany, Smithsonian Sciences; Instant Identification System Institution, PO Box 37012, NMNH MRC-166, (1/22/07-1/21/08).