commentary Challenges for taxonomy H Charles J Godfray Taxonomy the classification of living things has its origins in ancient Greece and in its modern form dates back nearly 250 years to when Linnaeus introduced the binomial classification still used today Linnaeus of course hugely underestimated the number of plants and animals on Earth As subsequent workers began to describe more and more species often in ignorance of each others work the resulting confusion and chaos threatened to destroy the whole enterprise while still in its infancy In today s jargon we might call this the first bioinformatics crisis Using the tools then available nineteenth century taxonomists solved this crisis in a brilliant way that has served the subject well since then They invented a complex set of rules that determine how a species should be named and associated with a type specimen how generic and higher taxonomic categories should be handled and how conflicts over the application of names should be resolved All these rules revolved around publications in books and scientific journals and their descendants form the current codes of zoological and biological nomenclature But today much of taxonomy is perceived to be facing a new crisis a lack of prestige and resources that is crippling the continuing cataloguing of biodiversity In the United Kingdom a Parliamentary Select Committee is currently conducting an enquiry into the health of the subject for the second time in 10 years and similar concerns are being expressed around the world In this article I shall first explore why descriptive taxonomy is in such straits in contrast its sister subject phylogenetic taxonomy is flourishing Then after this essentially negative exercise I will argue that taxonomy can prosper again but only if it reinvents itself as a twenty first century information science It needs to adopt some of the solutions that molecular biologists have developed to cope with the second bioinformatics crisis the huge explosion of sequence genomic proteomic and other molecular data The problem Why can t descriptive taxonomy attract large scale funds in the same way as other big programmes like the Human Genome Project or the Sloan Digital Sky Survey All three projects are enabling science not in themselves generating new ideas or testing hypotheses but allowing many new areas of research to be opened up NATURE VOL 417 2 MAY 2002 www nature com One reason is that taxonomists lack clearly achievable goals that are both realistic and relevant Of course it would be great to describe every species of organism on Earth but we are still monumentally uncertain as to how many species there are probably somewhere between 4 million and 10 million this goal is just not realistic at present There are various projects aimed at listing for example all the valid described species of animal in Europe or butterflies on Earth see Box 1 overleaf These aims are eminently achievable and very worthwhile but the results are like raw unannotated DNA sequences unexciting and of relatively little value in themselves to nonspecialists Taxonomists need to agree on deliverable projects that will receive wide support across the biological and environmental sciences and attract public interest A second problem is part of the legacy of more than 200 years of systematics Many taxonomists spend most of their career trying to interpret the work of nineteenthcentury systematicists deconstructing their often inadequate published descriptions or scouring the world s museums for type material that is often in very poor condition A depressing fraction of published systematic research concerns these issues In some taxonomic groups the past acts as a dead weight on the subject the complex synonymy and scattered type material deterring anyone from attempting a modern revision As Frank Thorsten Krell pointed out in Correspondence Nature 415 957 2002 original descriptions have to be referred to for ever independent of the paper s quality The problems do not always lie in the past Even today many species are being described poorly in isolated publications with no attempt to relate a new taxon to existing species and classifications Many of these new species will have been described before so sorting out the mess will be the headache of the next generation of taxonomists It is not surprising if funding bodies view much of what taxonomists do as poor value for money One of the astonishing things about T his discipline is made for the web it is information rich and often requires copious illustrations 2002 Macmillan Magazines Ltd From paper to screen is it time for taxonomy to break with tradition and unify on the Internet being a scientist at this particular time in history is the vast amount of information that is available essentially free via one s desktop computer I can download the sequences of millions of genes the positions of countless stars Yet with a few wonderful exceptions the quantity of taxonomic information available on the web is pitiful and what is present typically simple lists is of little use to non taxonomists But surely taxonomy is made for the web it is an information rich subject often requiring copious illustrations At present the output of much taxonomy is expensive printed monographs or papers in low circulation journals available only in specialized libraries These are not attractive deliverables for major research funders Two models of taxonomy The taxonomy of a group of organisms does not reside in a single publication or a single institution but instead is an ill defined integral of the accumulated literature on that group The literature is bound together and cross references itself using the venerable rules of taxonomy encapsulated in the codes But this is not the only way to organize a taxonomy The taxonomy of a particular group could reside in one place and be administered by a single organization It could be self contained and require reference to no other sources 17 NATURAL HISTORY MUSEUM LONDON The discipline will have to reinvent itself if it is to survive and flourish commentary My main argument is that to address the problems outlined above and for taxonomy to flourish now and in the future it has to move from the first to the second model from having a distributed to a unitary organization Such a massive task could only be accomplished group by group as resources became available I believe a number of things would then follow First the only