Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Preserving the evolutionary potential of floras in biodiversity hotspots


One of the biggest challenges for conservation biology is to provide conservation planners with ways to prioritize effort. Much attention has been focused on biodiversity hotspots1. However, the conservation of evolutionary process is now also acknowledged as a priority in the face of global change2. Phylogenetic diversity (PD) is a biodiversity index that measures the length of evolutionary pathways that connect a given set of taxa3,4. PD therefore identifies sets of taxa that maximize the accumulation of ‘feature diversity’. Recent studies, however, concluded that taxon richness is a good surrogate for PD5,6,7,8,9. Here we show taxon richness to be decoupled from PD, using a biome-wide phylogenetic analysis of the flora of an undisputed biodiversity hotspot—the Cape of South Africa. We demonstrate that this decoupling has real-world importance for conservation planning. Finally, using a database of medicinal and economic plant use10, we demonstrate that PD protection is the best strategy for preserving feature diversity in the Cape. We should be able to use PD to identify those key regions that maximize future options, both for the continuing evolution of life on Earth and for the benefit of society.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Taxon richness and phylogenetic diversity in the Cape.
Figure 2: Complementarity analysis of PD and genus richness.

Similar content being viewed by others


  1. 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 

  2. Mace, G. M., Gittleman, J. L. & Purvis, A. Preserving the tree of life. Science 300, 1707–1709 (2003)

    Article  ADS  CAS  Google Scholar 

  3. Faith, D. P. Conservation evaluation and phylogenetic diversity. Biol. Conserv. 61, 1–10 (1992)

    Article  Google Scholar 

  4. Vane-Wright, R. I., Humphries, C. J. & Williams, P. H. What to protect? Systematics and the agony of choice. Biol. Conserv. 55, 235–254 (1991)

    Article  Google Scholar 

  5. Brooks, T. M. et al. Global biodiversity conservation priorities. Science 313, 58–61 (2006)

    Article  ADS  CAS  Google Scholar 

  6. Polasky, S., Csuti, B., Vossler, C. A. & Meyers, S. M. A comparison of taxonomic distinctness versus richness as criteria for setting conservation priorities for North American birds. Biol. Conserv. 97, 99–105 (2001)

    Article  Google Scholar 

  7. Rodrigues, A. S. L., Brooks, T. M. & Gaston, K. J. in Phylogeny and Conservation (eds Purvis, A., Gittleman, J. L. & Brooks, T. M.) 101–119 (Cambridge University Press, Cambridge, UK, 2005)

    Book  Google Scholar 

  8. Rodrigues, A. S. L. & Gaston, K. J. Maximising phylogenetic diversity in the selection of networks of conservation areas. Biol. Conserv. 105, 103–111 (2002)

    Article  Google Scholar 

  9. Torres, N. M. & Diniz, J. A. F. Phylogenetic autocorrelation and evolutionary diversity of Carnivora (Mammalia) in conservation units of the New World. Genet. Mol. Biol. 27, 511–516 (2004)

    Article  Google Scholar 

  10. Survey of Economic Plants for Arid and Semi-Arid Lands. (SEPASAL) database 〈〉 (Royal Botanic Gardens, Kew, London, 1999)

  11. Goldblatt, P. & Manning, J. C. Plant diversity of the Cape region of southern Africa. Ann. Missouri Bot. Gard. 89, 281–302 (2002)

    Article  Google Scholar 

  12. Linder, H. P. The radiation of the Cape flora, southern Africa. Biol. Rev. 78, 597–638 (2003)

    Article  CAS  Google Scholar 

  13. Cowling, R. M. & Lombard, A. T. Heterogeneity, speciation/extinction history and climate: explaining regional plant diversity patterns in the Cape floristic region. Divers. Distrib. 8, 163–179 (2002)

    Article  Google Scholar 

  14. Cowling, R. M., Cartwright, C. R., Parkington, J. E. & Allsopp, J. C. Fossil wood charcoal assemblages from Elands Bay Cave, South Africa: implications for Late Quaternary vegetation and climates in the winter-rainfall fynbos biome. J. Biogeogr. 26, 367–378 (1999)

    Article  Google Scholar 

  15. Linder, H. P. & Midgley, J. J. Taxonomy, compositional biodiversity and functional biodiversity of fynbos. S. Afr. J. Sci. 90, 329–333 (1994)

    Google Scholar 

  16. Nixon, K. C. The parsimony ratchet, a new method for rapid parsimony analysis. Cladistics 15, 407–414 (1999)

    Article  Google Scholar 

  17. Sanderson, M. J. A nonparametric approach to estimating divergence times in the absence of rate constancy. Mol. Biol. Evol. 14, 1218–1231 (1997)

    Article  CAS  Google Scholar 

  18. Williams, P. H. & Humphries, C. J. in Biodiversity: a Biology of Numbers and Difference (ed. Gaston, K. J.) (Blackwell Science, Oxford, UK, 1996)

    Google Scholar 

  19. Goldblatt, P. et al. Radiation in the Cape flora and the phylogeny of peocock irises Moraea (Iridaceae) based on four plastid DNA regions. Mol. Phyl. Evol. 25, 341–360 (2002)

    Article  CAS  Google Scholar 

  20. Linder, H. P. Evolution of diversity: the Cape flora. Trends Plant Sci. 10, 536–541 (2005)

    Article  CAS  Google Scholar 

  21. 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 

  22. Cowling, R. M. & Proches, S. in Plant Diversity and Complexity Patterns: Local, Regional and Global Dimensions (eds Friis, I. & Balslev, H.) 273–288 (The Royal Danish Academy of Sciences And Letters, Copenhagen, 2005)

    Google Scholar 

  23. Midgley, G. F., Hannah, L., Roberts, R., MacDonald, D. J. & Allsopp, J. Have Pleistocene climatic cycles influenced species richness pattern in the greater Cape Mediterranean Region? J. Mediterr. Ecol. 2, 137–144 (2001)

    Google Scholar 

  24. Proches, S., Wilson, J. R. U. & Cowling, R. M. How much evolutionary history in a 10x10 m plot? Proc. R. Soc. Lond. B 273, 1143–1148 (2006)

    Article  Google Scholar 

  25. Erwin, T. L. An evolutionary basis for conservation strategies. Science 253, 750–752 (1991)

    Article  ADS  CAS  Google Scholar 

  26. Davies, T. J. et al. Darwin's abominable mystery: insight from a supertree of the angiosperms. Proc. Natl Acad. Sci. USA 101, 1904–1909 (2004)

    Article  ADS  CAS  Google Scholar 

  27. Wilson, K. A., McBride, M. F., Bode, M. & Possingham, H. P. Prioritizing global conservation efforts. Nature 440, 337–340 (2006)

    Article  ADS  CAS  Google Scholar 

  28. Goldblatt, P. & Manning, J. C. Cape Plants, a Conspectus of the Cape Flora in South Africa (National Botanical Institute of South Africa, Cape Town, South Africa, 2000)

    Google Scholar 

  29. Mooers, A. O., Heard, S. B. & Chrostowski, E. in Phylogeny and Conservation (eds Purvis, A., Brooks, T. L. & Gittleman, J. L.) (Oxford Univ. Press, Oxford, 2005)

    Google Scholar 

  30. APG. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II. Bot. J. Linn. Soc. 141, 399–436 (2003)

Download references


We thank E. Arnold, K. Balele, W. Barrington, N. Bergh, F. Conrad, L. Csiba, C. Cupido, A. Dold, the Fourcade Botanical Club, K. Davis, J. Donaldson, P. Drew, T. Fulcher, G. Gardiner, J. Gittleman, P. Goldblatt, N. Helme, E. Kapinos, A. Khunou, N. B. Lester, A. Mabunda, M. Powell, D. Snijman, K. Tolley, T. Trinder-Smith, A. G. Verboom, E. van Jaarsveld, S. Vetter, C. Williams, M. Wolfson, F. Woodvine, and especially I. Nänni, for assistance; the conservation authorities of the Western, Eastern and Northern Cape in South Africa for granting collecting permits as well as the managers of nature reserves and private landowners; A. Proust/iAfrika for the picture in Fig. 1; and T. Barraclough, M. Chase and H. Possingham for comments on the manuscript. We thank the Darwin Initiative for the Survival of Species, the South African National Biodiversity Institute, the University of Cape Town, the Royal Botanic Gardens Kew, the Bentham-Moxon Trust, the US National Science Foundation, the University of Virginia and the European Commission (HOTSPOTS/EDIT) for funding.

DNA sequences have been deposited at GenBank/EMBL under accession numbers AM234779–AM235167 (see also Supplementary Information)

Author information

Authors and Affiliations


Corresponding authors

Correspondence to Félix Forest or Vincent Savolainen.

Ethics declarations

Competing interests

DNA sequences have been deposited at GenBank/EMBL under accession numbers AM234779–AM235167 (see also Supplementary Information). Reprints and permissions information is available at The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Methods, Supplementary Table 1 and Supplementary Figures 1-6. (PDF 1380 kb)

Supplementary Table

This file contains a table listing the taxa included in the phylogenetic analysis of Cape angiosperm genera based on rbcL plastid sequences and associated Genbank/EMBL accession numbers. Genera with one Cape species recorded in the SEPASAL database ( are indicated. (PDF 694 kb)

Supplementary Information

This file contains the phylogenetic tree of the Cape flora (chronogram) and the optimization of the three types of utility. (PDF 564 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Forest, F., Grenyer, R., Rouget, M. et al. Preserving the evolutionary potential of floras in biodiversity hotspots. Nature 445, 757–760 (2007).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing