Feature

The Misnaming of Parts

What's in a name? A great deal if you're an unrecognised organism fighting to survive.

Adrian Paterson and Brent Emerson

Look at the old dusty scientists in older dusty rooms with a lifetime's work spent poring over smelly, preserved specimens. Dry. Outdated. Tedious. Irrelevant to today's fast-paced conservation-minded world where we know what to save. Who cares about varieties, subspecies and species?

These are the images and thoughts that often spring to mind with the words "taxonomy" and "systematics". Such views permeate most organisations and individuals involved with conservation work. Taxonomists and systematists in New Zealand seem to be suffering from a phenomenon that they are quite familiar with -- misclassification.

While taxonomy and systematics are both studies of biological diversity, they are not the same. Taxonomy is the science of classifying organisms into groups, including the naming of these groups. Taxonomy provides a quick catalogue of the diversity we are witness to. This is particularly true of organisms that are economically or aesthetically important to us. Hence, we have dozens of names for breeds within the single species of sheep, dogs, and cats, but only a single name for several similar species of feather lice in the Ancistrona group.

Taxonomy provides immediate benefits to conservation through the description of distinct groups of organisms. Like everything else, conservation has its politics, and undescribed species do not fare well within this arena. If the black stilt (Himantopus novaexelandiae) remained undescribed -- and hence unrecognised -- it would probably not be receiving the attention that it enjoys today. A wealth of data also exists in the form of taxonomic lists of species for regions, providing the ground plan for ecological and biogeographical studies. Studies of the later kind are proving valuable in identifying key areas for conservation.

Systematics differs from taxonomy by having an evolutionary basis. There is only one evolutionary history, therefore organisms can only be related in a distinct way. Systematics seeks to reconstruct this evolutionary relationship among organisms. Just as our relationships to our parents and grandparents cannot be changed, neither can the relationship of one species to another. It is this stability that is important in conservation work.

Informed Decision Making

Taxonomy and systematics are corner stones for informed conservation decisions. This has been recognised overseas by increased funding, particularly with regard to studying and maintenance of biodiversity. Much of this change in attitude has flowed on from increasing precision created by genetic analysis and a rigorous method of deducing relationships known as phylogenetics.

In New Zealand, the Department of Conservation (DoC) has taken the innovative step of producing a document entitled Setting priorities for the conservation of threatened species which uses 17 criteria based on five factors. One of these factors is taxonomic distinctiveness and can only be assessed by knowing the evolutionary relationships of species.

The tuatara is taxonomically distinct from other reptiles because it is the only living species of a group that arose about 60 million years ago. As a less obvious example of taxonomic distinctiveness, genetic work on seabirds has shown that mollymawks may be more distinct from albatrosses than is currently accepted.

While DoC is to be commended for including taxonomic distinctiveness in setting conservation priorities, in reality it constitutes a small proportion of the assessment. For example, eight subspecies of flax snail (Placostylus ambagiosus) are each given higher priority than the single representative of the genus Spelungula, the Nelson cave spider (S. cavernicola). Systematics can direct conservation efforts toward saving more of the evolutionary variety that New Zealand possesses.

Knowledge of relationships can also assist management decisions for rare or unstudied species by using information gathered from closely related or sister species.

The Cromwell chafer beetle (Prodontria lewisi) is restricted to an 81-hectare reserve and little is known about its basic ecology. It is desirable that it suffer as little study and manipulation as possible. A systematic study of the genus will reveal sister species to the Cromwell chafer. Using information on the ecologies of the sister species will allow more informed management decisions to be made for the Cromwell chafer. As an example, a probable sister species occurring around Alexandra survives in a highly modified habitat. This strengthens the belief that the Cromwell chafer is not exclusively reliant on silver tussock as a food source for the root-feeding larvae; exotic plants may now be assuming this role.

It is most important for conservation that we know what is out there to conserve before it can be conserved. A recent study at the University of Otago on native freshwater galaxiid fish (the returning juveniles of some species that make up the whitebait catch) is a good example. Originally, the study was focussed on comparing genetic diversity within both migratory and nonmigratory species. It was soon apparent that there were substantially more differences within the species Galaxias vulgaris than is normally seen within a species. Further work has indicated the possibility of several different species of "G.vulgaris" instead of one within the Taieri river catchment alone, some with very restricted habitats. These findings have important implications for the conservation of G.vulgaris. Instead of dealing with a relatively common, widespread species, there are several localised species which may be in need of protection.

Decline in Work

Despite the increasing need for systematics and the growing sophistication of phylogenetic methods, recent years have seen a decline in systematic work in New Zealand. Attracting funds for this type of work is difficult. The reasons appear twofold. The main output from systematic work is information for scientists to use in other disciplines. Although this information is often vital for scientists, it is less tangible and immediate than direct conservation research such as radio-tracking wekas or diet analysis of kakapo.

In addition, systematists appear to be overcautious and have been accused of "mental masturbation". After all, wildlife managers want answers yesterday, not some time next year. Systematists, on the other hand, are interested in correctly reconstructing the true relationships of species and building a stable framework for future research. This can only be achieved by inferring from today's evidence (DNA, morphology, behaviour, biogeography) -- we cannot travel back in time to watch evolution occur.

There does appear to be some change in attitude to systematics. Last year the Ecological Society of New Zealand held a joint session with the Systematics Association. This mingling of scientists from two traditionally disparate fields should be both applauded and encouraged. Implications from New Zealand ratifying the Rio earth summit were discussed. It was noted that New Zealand will be bound by the treaty to actively research biodiversity. Systematics and taxonomy, as studies of biodiversity, should directly benefit.

Ultimately, systematics is important in conservation not only for increasing efficiency, accuracy, rigour and information, but for the most basic of reasons best summarised by biologist E.O. Wilson:

Certain measurements are crucial to our ordinary understanding of the universe. What, for example, is the mean diameter of the earth? It is 12,742 kilometers. How many stars are there in the Milky Way? Approximately 1011. How many genes are there in a small virus particle? There are 10 (in a X174 phage). What is the mass of an electron? It is 9.1 x 10^{- 28}grams.

And how many species of organisms are there on earth? We do not know, not even to the nearest order of magnitude.

Adrian Paterson and Brent Emerson are in the Department of Entomology and Animal Ecology at Lincoln University.