Field Museum Public Relations
A new study, published in the Proceedings of the National Academy of Sciences (PNAS), reveals a common fungus, long thought to be a single species, is in fact, at least 126 different species. The Field Museum's Adjunct Curator Robert Lücking, PhD, and colleagues from around the world sequenced the DNA of the fungus, as well as conducted field studies and microscopic analyses. Based on this research, the scientists now predict the existence of at least 450 species! “This result is dramatic; we do not know of any other group of macroorganisms where such unrecognized species diversity had been hidden. It may be, and may remain, unparalleled,” says Lücking.
The fungus has been known under a variety of names – including Cora pavonia and Dictyonema glabratum. The genus name Cora best translates as Heart Lichen, due to the often heart-shaped configuration of the lichen. It is found in cool-temperate to tropical climates, from Florida to as far south as Patagonia in Chile and Argentina, as well as in the Galápogos Islands and Saint Helena. A familiar sight along roadbanks, it is capable as acting as a biological fertilizer, important because soils in these areas are often nutrient-poor.
“This study shows the importance of taxonomic work in recognizing and cataloguing biological diversity. Knowing species is critical for assessing ecosystem function and habitat conservation,” explains Lücking. Many of the previously unrecognized species occur in highly threatened montane shrublands known as paramos—some already converted into agricultural landscapes, others threatened by activities such as mining, while others may come under threat simply due to population growth.
Because the fungus is found in such diverse and widespread areas, the collaboration between scientists was key. Researchers contributing to the study were based at The Field Museum, George Mason University, the Charles Darwin Research Station, Universidad Francisco José de Caldas as well as Costa Rica, Colombia, and Ecuador. “Such collaborations not only make research much more effective, they also guarantee that the data and results are disseminated and put to good work directly in the countries from which they were obtained,” says Lücking.
For now, the challenge for these scientists remains to formally describe all the newly recognized species, which is required by the International Code of Nomenclature. “We’ve finished work on just a dozen species, so much work remains to be done to describe those based on the study. This doesn’t include those we predict to exist but have not yet been discovered,” says Lücking. How long would naming all species take? Lücking explains that a complete description takes a few hours; for 450 species, a single person would have to work about a year, doing nothing else!
This Herculean task may once have been approached by a single scientist, but today scientists work more effectively by forming international collaborations and by using tools that facilitate the work, such as automated taxonomic keys and species descriptions generated from a central database. “These are actually pretty exciting times, allowing us to integrate all kinds of tools and to work together across borders. Nobody would have imagined that when taxonomy took off historically some 250 years ago.”
This study was sponsored by the National Science Foundation grants DEB 0841405, DEB 0715660, and DEB 0206125. Photos available upon request.