Combination of old and new improved taxonomy

More types and fewer mistakes thanks to new combination of methods

Example of Linné's classification system of plants © historical
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No one can say exactly how diverse nature really is. One of the reasons is that both traditional and modern methods of delimiting species are susceptible to error. An international team of researchers has now developed a new, integrative taxonomy approach that reduces the average error rate for species delimitation from one third to about three percent.

The Swedish naturalist and taxonomy pioneer Carl von Linné developed in the 18th century in addition to the binomial nomenclature and a principle of order for animal and plant species. He based his system mainly on features of external morphology. "Of course, there are many species of animals, so-called cryptic species, that are very similar in nature, but independent and occupy a completely different role in the ecosystem. So morphology is not always a sure guide for the delimitation of species, "says Professor Schlick-Steiner from the Institute of Ecology, describing a basic problem of taxonomy.

She and her international team have now shown that not only morphological access but also modern taxonomic methods such as DNA methods, cytogenetics or chemistry are highly susceptible to error. That's why the scientists in their study, published in the prestigious journal Annual Review of Entomology, have developed a new integrative taxonomy approach.

Proven combined with new

"We analyzed 184 arthropod studies from 48 journals and were able to show that when used in isolation, all methods of speciation have a high error rate. On average, the error rate is one-third, "says Schlick-Steiner. She and her colleagues therefore propose an integrative taxonomy that combines multiple methods, incorporating traditional morphology.

"Morphology has a somewhat dusty coat but is still very important. Using only DNA methods dispenses with a great deal of knowledge that has been accumulated over the centuries. In addition, even DNA methods have their errors ". According to Schlick-Steiner, it makes sense to combine morphology with a DNA method and another method that can be selected according to the research project. "That way we can reduce the average error rate from one third to about three percent". display

Application in conservation, evolutionary biology and entomology

Incidentally, the high error rate is not a purely academic problem, but also has practical effects. "Today we are talking about a biodiversity crisis without knowing exactly how many species we have and what role they play in the ecosystem. Presumably, it is far more than previously thought, "explains Schlick-Steiner. Apart from that, other areas of research benefit from good taxonomy, such as evolutionary biology, conservation biology, crop protection and medical entomology.

Thus, it has been found that there are cryptic species in the Anopheles mosquitoes, which differ in the transmission of malaria in the hazard potential. With this knowledge, resources can be used more efficiently in the fight against a disease that requires one million lives each year. "The taxonomy is unfortunately a stepchild of modern biology, " the ecologist regrets. "Our study is therefore also an appeal to taxonomy".

(University Innsbruck, 05.10.2009 - NPO)