Portal de Periódicos da CAPES

THE DIVERSIFICATION OF HALENIA (GENTIANACEAE): ECOLOGICAL OPPORTUNITY VERSUS KEY INNOVATION

2003; Oxford University Press; Volume: 57; Issue: 11 Linguagem: Inglês

10.1111/j.0014-3820.2003.tb01495.x

1558-5646

K. Bernhard von Hagen, Joachim W. Kadereit,

Plant and animal studies

EvolutionVolume 57, Issue 11 p. 2507-2518 Free Access THE DIVERSIFICATION OF HALENIA (GENTIANACEAE): ECOLOGICAL OPPORTUNITY VERSUS KEY INNOVATION K. B. von Hagen, K. B. von Hagen Institut fuer Geobotanik, Martin-Luther-Universitaet Halle-Wittenberg, Neuwerk 21, 06099 Halle, Germany E-mail: vonhagen@botanik.uni-halle.deSearch for more papers by this authorJ. W. Kadereit, J. W. Kadereit Institut fuer Spezielle Botanik und Botanischer Garten, Johannes Gutenberg-Universitaet Mainz, Bentzelweg 9, 55099 Mainz, Germany E-mail: kadereit@mail.uni-mainz.deSearch for more papers by this author K. B. von Hagen, K. B. von Hagen Institut fuer Geobotanik, Martin-Luther-Universitaet Halle-Wittenberg, Neuwerk 21, 06099 Halle, Germany E-mail: vonhagen@botanik.uni-halle.deSearch for more papers by this authorJ. W. Kadereit, J. W. Kadereit Institut fuer Spezielle Botanik und Botanischer Garten, Johannes Gutenberg-Universitaet Mainz, Bentzelweg 9, 55099 Mainz, Germany E-mail: kadereit@mail.uni-mainz.deSearch for more papers by this author First published: 09 May 2007 https://doi.org/10.1111/j.0014-3820.2003.tb01495.xCitations: 34AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Abstract The plant genus Halenia (Gentianaceae) consists of herbs growing in temperate and tropical alpine habitats and most species possess flowers in which nectar is produced in spurs. This probably helps reward only specialized long-tongued pollinators, and a narrow pollinator/flower relationship is thought to accelerate diversification rates (a key innovation). To test the pattern of diversification of Halenia against the unspurred sister group we reconstructed phylogenetic relationships among 22 species plus outgroups using nuclear ITS and chloroplast rpl16 intron sequence data. We show that Halenia originated in East Asia and migrated via North America into Central America. From there, it colonized South America three times independently, probably within the last million years. Significant changes in diversification rates were found during the evolution of Halenia using a sister group method, a likelihood method, and a diversity-through-time plot. In contrast to other studies, we could not observe a direct speciation rate effect of the evolution of nectar spurs in comparison with the unspurred sister group of Halenia. Rather, increases in diversification occurred following the colonization of Central and South America by spurred progenitor taxa. This later switch in diversification may have resulted from the availability of new geographical and ecological opportunities, or from the availability of more and different pollinators in these regions. Following the latter hypothesis, the nectar spurs were a preadaption and functioned as a key innovation only in this new biotic environment. After an initial rapid increase, a reduction in diversification rate was observed in Central America, probably illustrating density dependence of speciation rates. Finally, we found preliminary evidence for the key innovation hypothesis in geologically young spurred and unspurred lineages of Halenia in South America. Citing Literature Volume57, Issue11November 2003Pages 2507-2518 ReferencesRelatedInformation