Systematics: Relevance to the Twenty‐first Century


An overview of systematics, the naming, classifying and ordering of life, shows that it has never been more relevant than in the present time of environmental crisis and species loss. Only 1.9 million of the many millions of species have been named and classified, making it difficult to use and conserve them. Molecular techniques combined with cladistic methods and high‐powered computing ability are producing predictive phylogenies of many groups of organisms and are bringing us closer to working out an accurate tree of life. Evolutionary development is a rapidly expanding field that is helping to explain the molecular mechanisms that control development processes. In future deoxyribonucleic acid (DNA) barcoding of organisms is likely to be in general use to identify organisms, but it will not replace the study of the morphology of organisms. The data basing of large museum and herbarium collections is greatly enhancing the use of collections for systematics research. E‐alpha taxonomy using standardised descriptors is gradually gaining momentum.

Key Concepts:

  • Systematics and naming is basic to all other studies of organisms.

  • It is urgent to increase systematic work because of the continuing loss of species.

  • DNA barcoding is going to be an invaluable tool, but will not altogether replace morphological studies. It is most useful for linking different stages of organisms: seedlings with parent plants, larvae with adult insects.

  • Evolutionary development (Evo‐Devo) is helping our understanding of the molecular mechanisms of floral development and changes.

  • Phylogeography is helping to elucidate the historic movements of organisms around the world.

  • Modern systematics leads to predictive classifications which are most useful for the discovery of new useful chemicals in organisms.

  • Alpha taxonomy is still pertinent and necessary for the practical identification of species and for the users of taxonomy.

  • E‐alpha taxonomy is leading to a better standardisation of descriptors of organisms.

Keywords: systematics; molecular taxonomy; cladistics; phylogeny; phylogeography; barcoding; evolutionary development; classification; databases; alpha taxonomy

Figure 1.

This example of a cladogram shows the hypothesised phylogeny of the plant families belonging to the Caryophyllidae. The numbers below and above the branches are of measures that show the strength of each branch. Fitch branch lengths are above the branches and bootstrap percentages below the branches. These are statistical measurements of support for a particular group on the cladogram. The higher the number the more confidence there is in the group. Reproduced with permission of the Trustees of the Royal Botanic Gardens, Kew.



Angiosperm Phylogeny Group (1998) An ordinal classification for the families of flowering plants. Annals of the Missouri Botanical Garden 85: 531–553.

APG III (2009) An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III. Botanical Journal of the Linnean Society 161: 105–121.

Avise JC (2000) Phylogeography: The History and Formation of Species. Cambridge, MA: Harvard University Press.

Avise JC (2009) Phylogeography: retrospect and prospect. Journal of Biogeography 36: 3–15.

Bremmer K and Wanntorp HE (1978) Phylogenetic systematics in botany. Taxon 27: 317–329.

Chase MW and Albert V (1998) A perspective on the contribution of plastid rbcL sequences to angiosperm phylogenetics. In: Soltis DE, Soltis PS and Doyle JJ (eds) Molecular Systematics of Plants, vol. 2: DNA Sequencing, pp. 488–507. Boston: Kluwer.

Chase MW, Cowan RS, Hollingsworth PM et al. (2007) A proposal for a standardized protocol to barcode all landplants. Taxon 56: 295–299.

Chase MW, Soltis DE, Olmstead RG et al. (1993) Phylogenetics of seed plants: an analysis of nucleotide sequences from plastid gene rbcL. Annals of the Missouri Botanical Gardens 80: 528–580.

Coen ES and Meyerowitz EM (1991) The war of the whorls: genetic interactions controlling flower development. Nature 353: 31–37.

Crane PR, Friis EM and Pedersen KR (1995) The origin and early diversification of angiosperms. Nature 374: 27–33.

Devey DS, Chase MW and Clarkson JJ (2009) A stuttering start to plant DNA barcoding: microsatellites present a previously overlooked problem in non‐coding plastid regions. Taxon 58: 7–15.

Doyle JA and Endress PK (2010) Integrating early Cretaceous fossils into the phylogeny of living angiosperms: Magnoliidae and eudicots. Journal of Systematics and Evolution 48: 1–35.

Ferri G, Alu M, Corradini B and Beduschi G (2009) Forensic botany: species identification of botanical trace evidence using a multigene barcoding approach. International Journal of Legal Medicine 123: 395–401.

Ford CS, Ayres KL, Toomey L et al. (2009) Selection of candidate coding DNA barcoding regions for use on land plants. Botanical Journal of the Linnean Society 159: 1–11.

Friis EM, Pedersen KR and Crane PR (2010) Diversity in obscurity: fossil flowers and the early history of angiosperms. Philosophical Transactions of the Royal Society Series B 365: 359–382.

Funk VA and Stuessy TF (1978) Cladistics for the practising plant taxonomist. Systematic Botany 3: 159–178.

Godfray HCJ (2002) Challenges for taxonomy. Nature 417: 17–19.

Haston E, Richardson JE, Stevens PF, Chase MW and Harris DJ (2009) The linear Angiosperm Phylogeny Group (LAPG) III: a linear sequence of the families in APG III. Botanical Journal of the Linnean Society 161: 128–131.

Hennig W (1966) Phylogenetic Systematics. Urbana, IL: University of Illinois Press.

Herbert PDN, Cywinska A, Ball SL and deWaard JR (2003) Biological identification through DNA barcodes. Proceedings of the Royal Society London, Series B: Biological Science 270: 313–321.

Hollingsworth PM, Forrest LL, Spouge JL et al. (2009) A DNA barcode for land plants. Proceedings of the National Academy of Sciences of the USA 106: 12794–12797.

Hopkins GW and Freckleton (2002) Decline in the numbers of amateur and professional taxonomists: implications for conservation. Animal Conservation 5: 245–249.

Immink RGH, Kaufmann K and Angenent GC (2010) The ‘ABC’ of MADS domain protein behaviour and interactions. Seminars in Cell and Developmental Biology 21: 87–93.

Janzen DH, Hajibabaei M, Burns JM et al. (2005) Wedding biodiversity inventory of a large complex Lepidoptera fauna with DNA barcoding. Philosophical Transactions of the Royal Society Series B 360: 1835–1845.

Kelly LJ, Ameka GK and Chase MW (2010) DNA barcoding of African Podostemaceae (river‐weeds): a test of proposed barcode regions. Taxon 59: 251–260.

Kress JW, Wurdack KJ, Zimmer EA, Weigt LA and Janzen DH (2005) Use of DNA barcodes to identify flowering plants. Proceedings of the National Academy of Science of the USA 102: 8369–8374.

Mayo SJ, Allkin B, Baker W et al. (2008) Alpha e‐taxonomy: responses from the systematics community to the biodiversity crisis. Kew Bulletin 63: 1–16.

Parnell J (1993) Plant taxonomic research, with special reference to the tropics: problems and potential solutions. Conservation Biology 7: 809–814.

Paton AJ, Brummitt N, Govaerts R et al. (2008) Towards target 1 of the global strategy for plant conservation: a working list of all known plant species – progress and prospects. Taxon 57: 602–611.

Scoble MJ, Clark BR, Godfray HCJ, Kitching IJ and Mayo SJ (2007) Revisionary taxonomy in a changing e‐landscape. Tijdschrift voor Entomologie 150: 305–317.

Soltis DE, Moore MJ, Burleigh G and Soltis PS (2009) Molecular markers and concepts of plant evolutionary relationships: progress, promise and future prospects. Critical Reviews in Plant Sciences 28: 1–15.

Soltis DE and Soltis PS (1998) Choosing an approach and an appropriate gene for phylogenetic analysis. In: Soltis DE, Soltis PS and Doyle JJ (eds) Molecular Systematics of Plants, vol. 2: DNA Sequencing, pp. 1–42. Boston: Kluwer.

Soltis DE, Soltis PS, Chase MW et al. (2000) Angiosperm phylogeny inferred from a combined data set of 185‐DNA, rbcL, and atpB sequences. Botanical Journal of the Linnean Society 133: 381–461.

Stevens PF (1991) Character states, morphological variation and phylogenetic analysis: a review. Systematic Botany 16: 553–583.

Systematics Agenda 2000 (1994) New York: American Museum of Natural History and The New York Botanical Garden.

Taylor DW and Hickey LJ (1992) Phylogenetic evidence for the herbaceous origin of angiosperms. Plant Systematics and Evolution 180: 137–156.

Volz SM and Renner SS (2009) Phylogeography of the ancient Eurasian medicinal plant genus Bryonia (Cucurbitaceae) inferred from nuclear and chloroplast genes. Taxon 58: 550–560.

Further Reading

Carol SB (2005) Endless Forms Most Beautiful: The New Science of Evo Devo and the Making of the Animal Kingdom. New York: Norton.

Curry GB and Humphries CJ (eds) (2007) Biodiversity Databases: Techniques, Politics and Applications. Boca Raton: CRC Press, Taylor & Francis Group.

Forey PL, Humphries CJ, Kitching IL et al. (1992) Cladistics: A Practical Course in Systematics. Oxford: Clarendon Press.

Forey PL, Humphries CJ and Vane‐Wright RI (eds) (1994) Systematics and Conservation Evaluation. Oxford: Clarendon Press.

Groombridge B (ed.) (1992) Global Biodiversity: Status of the Earth's living resources. London: Chapman and Hall.

Heywood VH, Brummitt RK, Culham A and Seberg O (2007) Flowering Plant Families of the World. Kew: Royal Botanic Gardens.

Judd WS, Campbell CS, Kellogg EA, Stevens PF and Donogue MJ (2007) Plant Systematics: A Phylogenetic Approach, 3rd edn, Sunderland, MA: Sinauer.

Krebs JR (ed.) (1992) Evolution and Biodiversity – The New Taxonomy. Report of the Natural Environmental Research Council, Swindon, UK.

Soltis DE, Soltis PS and Doyle JJ (eds) (1998) Molecular Systematics of Plants, Vol. 2. Boston: Kluwer.

Stuessy TF (2009) Plant Taxonomy: The Systematic Evaluation of Comparative Data, 2nd edn. New York: Columbia University Press.

Stuessy TF, Hörandl E and Mayer V (2000) Plant systematics: a half century of progress (1950–2000) and future challenges. Jubilee Series, Taxon 49: 401–501.

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Prance, Ghillean T(Jan 2011) Systematics: Relevance to the Twenty‐first Century. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0003608.pub2]