Present address: Jagiellonian University, ul. Gronostajowa 7, 30-387 Kraków, Poland
How sympatric is speciation in the Howea palms of Lord Howe Island?
Article first published online: 10 AUG 2009
© 2009 Blackwell Publishing Ltd
Volume 18, Issue 17, pages 3629–3638, September 2009
How to Cite
BABIK, W., BUTLIN, R. K., BAKER, W. J., PAPADOPULOS, A. S. T., BOULESTEIX, M., ANSTETT, M.-C., LEXER, C., HUTTON, I. and SAVOLAINEN, V. (2009), How sympatric is speciation in the Howea palms of Lord Howe Island?. Molecular Ecology, 18: 3629–3638. doi: 10.1111/j.1365-294X.2009.04306.x
W.B. was a postdoc researcher at Silwood Park, now replaced by M.B. Together with PhD student A.S.T.P., M.B. works on the speciation genetics of plants of Lord Howe Island. R.K.B. is professor at the University of Sheffield and is interested in the genomics of the Howea palms. W.J. Baker is Head of Palm Section at Kew and has been working with V.S. on Howea for many years. M.-C. Anstett has been collaborating with the team on pollination biology, she has now left Montpellier to run her own stable yard. C.L. is professor at the University of Fribourg and was working with the team while still at Kew last year. I.H. is a scientist at the Museum of LHI. V.S. is the PI of the project, and works on the genomics of speciation in various taxa.
- Issue published online: 20 AUG 2009
- Article first published online: 10 AUG 2009
- Received 20 March 2009; revision received 8 June 2009; accepted 9 June 2009
- genetic differentiation;
- Lord Howe Island;
The two species of the palm genus Howea (Arecaceae) from Lord Howe Island, a minute volcanic island in the Tasman Sea, are now regarded as one of the most compelling examples of sympatric speciation, although this view is still disputed by some authors. Population genetic and ecological data are necessary to provide a more coherent and comprehensive understanding of this emerging model system. Here, we analyse data on abundance, juvenile recruitment, pollination mode and genetic variation and structure in both species. We find that Howea forsteriana is less abundant than Howea belmoreana. The genetic data based on amplified fragment length polymorphisms markers indicate similar levels of variation in the two species, despite the estimated census population size of H. belmoreana being three times larger than that of H. forsteriana. Genetic structure within species is low although some weak isolation by distance is detectable. Gene flow between species appears to be extremely limited and restricted to early-generation hybrids – only three admixed individuals, classified as F2s or first generation backcrosses to a parental species, were found among sampled palms. We conclude that speciation in Howea was indeed sympatric, although under certain strict definitions it may be called parapatric.