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Unmatched tempo of evolution in Southern African semi-desert ice plants

Nature volume 427, pages 63–65 (2004)Cite this article

Abstract

The Succulent Karoo is an arid region, situated along the west coast of southern Africa. Floristically this region is part of the Greater Cape Flora1 and is considered one of the Earth's 25 biodiversity hotspots2. Of about 5,000 species occurring in this region, more than 40% are endemic3. Aizoaceae (ice plants) dominate the Succulent Karoo both in terms of species numbers (1,750 species in 127 genera) and density of coverage3,4. Here we show that a well-supported clade within the Aizoaceae, representing 1,563 species almost exclusively endemic to southern Africa, has diversified very recently and very rapidly. The estimated age for this radiation lies between 3.8 and 8.7 million years (Myr) ago, yielding a per-lineage diversification rate of 0.77–1.75 per million years. Both the number of species involved and the tempo of evolution far surpass those of any previously postulated continental or island plant radiation5,6,7. Diversification of the group is closely associated with the origin of several morphological features and one anatomical feature. Because species-poor clades lacking these features occur over a very similar distribution area, we propose that these characteristics are key innovations that facilitated this radiation.

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Figure 1: Parsimony analysis.

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References

  1. Jürgens, N. A new approach to the Namib region. Part 1: phytogeographic subdivision. Vegetatio 97, 21–38 (1991)

    Google Scholar 

  2. Myers, N., Mittermeier, R. A., Mittermeier, C. G., da Fonseca, G. A. B. & Kent, J. Biodiversity hotspots for conservation priorities. Nature 403, 853–858 (2000)

    Article  ADS  CAS  Google Scholar 

  3. Jürgens, N. Untersuchungen zur Ökologie sukkulenter Pflanzen des südlichen Afrika. Mitt. Inst. Allg. Bot. Hamburg 21, 139–365 (1986)

    Google Scholar 

  4. Ihlenfeldt, H.-D. Diversification in an arid world: The Mesembryanthemaceae. Annu. Rev. Ecol. Syst. 25, 521–546 (1994)

    Article  Google Scholar 

  5. Richardson, J. E. et al. Rapid and recent origin of species richness in the Cape flora of South Africa. Nature 412, 181–183 (2001)

    Article  ADS  CAS  Google Scholar 

  6. Richardson, J. E., Pennington, R. T., Pennington, T. D. & Hollongsworth, P. M. Rapid diversification of a species-rich genus of neotropical rain forest trees. Science 293, 2242–2245 (2001)

    Article  ADS  CAS  Google Scholar 

  7. Baldwin, B. G. & Sanderson, M. J. Age and rate of diversification of the Hawaiian silversword alliance (Compositae). Proc. Natl Acad. Sci. USA 95, 9402–9406 (1998)

    Article  ADS  CAS  Google Scholar 

  8. Schmiedel, U. & Jürgens, N. Community structure on unusual islands: quartz-fields in the Succulent Karoo, South Africa. Plant Ecol. 142, 57–69 (1999)

    Article  Google Scholar 

  9. Hendey, Q. B. Langebaanweg. A Record of Past Life (South African Museum, Cape Town, 1982)

    Google Scholar 

  10. Axelrod, D. I. & Raven, P. H. in Biology and Ecology of Southern Africa (ed. Werger, M. J. A.) 77–130 (The Hague, Junk, 1978)

    Book  Google Scholar 

  11. Ward, J. D., Seely, M. K. & Lancaster, N. On the antiquity of the Namib. S. Afr. J. Sci. 79, 175–183 (1983)

    Google Scholar 

  12. Ward, J. D. & Corbett, I. Towards an age of the Namib. Transvaal Mus. Monogr. 7, 17–26 (1990)

    Google Scholar 

  13. Magallón, S. & Sanderson, M. J. Absolute diversifiation rates in Angiosperm clades. Evolution 55, 1762–1780 (2001)

    Article  Google Scholar 

  14. Eriksson, O. & Bremer, B. Pollination systems, disperal modes, lifeforms, and diversification rates in Angiosperm families. Evolution 46, 258–266 (1992)

    Article  Google Scholar 

  15. Mayhew, P. J. Shifts in hexapod diversification and what Haldane could have said. Proc. R. Soc. Lond. B 269, 969–974 (2002)

    Article  Google Scholar 

  16. Hulbert, R. C. Jr The rise and fall of an adaptive radiation. Paleobiology 19, 216–234 (1993)

    Article  Google Scholar 

  17. McCune, A. R. in Molecular Evolution and Adaptive Radiation (eds Givnish, T. J. & Sytsma, K. J.) 585–610 (Cambridge Univ. Press, 1997)

    Google Scholar 

  18. Scott, L., Steenkamp, M. & Beaumont, P. B. Palaeoenvironments in South Africa at the Pleistocene–Holocene transition. Quat. Sci. Rev. 14, 937–947 (1995)

    Article  ADS  Google Scholar 

  19. Landrum, J. V. Wide-band tracheids in leaves of genera in Aizoaceae: the systematic occurrence of a novel cell type and its implications for the monophyly of the subfamily Ruschioideae. Pl. Syst. Evol. 227, 49–61 (2001)

    Article  Google Scholar 

  20. Mauseth, J. D., Uosumi, Y., Plemons, B. J. & Landrum, J. V. Structural and systematic study of an unusual tracheid type in cacti. J. Plant Res. 108, 517–526 (1995)

    Article  Google Scholar 

  21. Parolin, P. Seed expulsion in fruits of Mesembryanthema (Aizoaceae): a mechanistic approach to study the effect of fruit morphological structures on seed dispersal. Flora 196, 313–322 (2001)

    Article  Google Scholar 

  22. Klak, C., Khunou, A., Reeves, G. & Hedderson, T. A phylogenetic hypothesis for the Aiozoaceae (Caryophyllales) based on four plastid DNA regions. Am. J. Bot. 90, 1433–1445 (2003)

    Article  CAS  Google Scholar 

  23. Swofford, D. L. PAUP*4.0b2: Phylogenetic Analysis Using Parsimony (Sinauer Associates, Sunderland, Massachusetts, 1998)

    Google Scholar 

  24. Fitch, W. M. Toward defining the course of evolution: minimum change for a specified tree topology. Syst. Zool. 20, 406–416 (1971)

    Article  Google Scholar 

  25. Felsenstein, J. Confidence limits on phylogenies: an approach using bootstrap. Evolution 39, 783–791 (1985)

    Article  Google Scholar 

  26. Sanderson, M. J. A non parametric approach to estimating divergence times in the absence of rate constancy. Mol. Biol. Evol. 14, 1218–1232 (1997)

    Article  CAS  Google Scholar 

  27. Rambaut, A. & Charleston, M. TreeEdit version 1.0 alpha 4–61 [online] 〈http://evolve.zoo.ox.ac.uk/software/TreeEdit.html〉 (2000).

  28. Scott, L., Anderson, H. M. & Anderson, J. M. in Vegetation of Southern Africa (eds Cowling, R. M., Richardson, D. M. & Pierce, S. M.) 62–84 (Cambridge Univ. Press, 1997)

    Google Scholar 

  29. Tankard, A. J. & Rogers, J. Late Cenozoic palaeoenvironments on the west coast of Southern Africa. J. Biogeogr. 5, 319–337 (1978)

    Article  Google Scholar 

  30. Wikström, N., Savolainen, V. & Chase, M. Evolution of the angiosperms: calibrating the family tree. Proc. R. Soc. Lond. B 268, 1–10 (2001)

    Article  Google Scholar 

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Acknowledgements

We thank P. Bruyns, A. Ellis and T. Verboom for critical discussion and comments, and G. Aguilar, F. Conrad and A. Khunou for technical support. This research was supported by the National Botanical Institute, Cape Town, the Mesemb Study Group (UK) and grants from The National Research Foundation, and by The University of Cape Town's University Research Committee (T.A.H.).

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Authors and Affiliations

  1. Bolus Herbarium, Department of Botany, University of Cape Town, 7701, Rondebosch, South Africa

    C. Klak & T. Hedderson

  2. Leslie Hill Molecular Systematics Laboratory, Kirstenbosch Research Centre, National Botanical Institute Cape Town, Private Bag X7, 7735, Claremont, South Africa

    G. Reeves

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  1. C. Klak
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Correspondence to C. Klak.

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Klak, C., Reeves, G. & Hedderson, T. Unmatched tempo of evolution in Southern African semi-desert ice plants. Nature 427, 63–65 (2004). https://doi.org/10.1038/nature02243

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