Summary of the talk that Anna Marie Roos (University of Lincoln) gave on 3rd February 2014
The understanding of Earth’s biodiversity depends critically on the accurate identification and nomenclature of species. Whenever a new species is discovered, under the International Code of Zoological Nomenclature, it is given a scientific name using binomial nomenclature and a “type” specimen is preserved, usually in a museum or research collection, so that other researchers can refer to it for physical details about the species. The type specimen is considered to be the representative for the entire species, exemplifying the defining features of that particular species. However, many species were described centuries ago, and in a surprising number of cases their nomenclature or type material remain unclear or inconsistent.
An elephant. Woodcut after C. Gessner.
Credit: Wellcome Library, London.
A prime example is provided by Elephas maximus, or the Asian elephant, one of the most well-known mammalian species. In 1758, Linneaus gave this name to the creature in his definitive work, the 10th edition of the Systema Naturae. In his description, Linneaus cited several “syntypes” or examples of elephant specimens in Europe, and he did not make any distinction between Asian or African Elephants. For him, an elephant was an elephant. He simply did not see enough live specimens to distinguish between the two.
A remarkable specimen referred to by Linnaeus is the well-preserved, near-complete, body of an elephant foetus in a spirit jar, held today at the Swedish Museum of Natural History (NRM) in Stockholm. This specimen was initially owned by the Dutch West India Company, and later became part of Albertus Seba’s natural history collection. Linnaeus acquired the specimen after convincing King Adolf Frederick of Sweden to purchase it for his personal collection: “I am pleased that the little elephant has arrived. If he costs a lot, he was worth it. Certainly, he is as rare as a diamond,” (May 18, 1753).
The taxonomist subsequently described the fetus in his Systema Naturae as Elephas maximus, and it eventually became the type specimen for the Asian elephant. But when the specimen was transferred to the Swedish Natural History Museum in the early 1800s, the curators began to suspect the baby was actually an African elephant, as it had large ears and domed head. In the early 2000s, Anthea Gentry, a mammal curator at the London Natural History Museum (NHM) thought much the same thing.
Although the animal’s DNA proved too degraded to yield conclusive evidence, Tom Gilbert and his colleague Enrico Cappellini at the University of Copenhagen turned to the elephant’s proteins, which were more stable. Specifically, they used morphological, ancient DNA (aDNA), and high-throughput ancient proteomic analyses to demonstrate that this fetus is actually an African elephant, genus Loxodonta, NOT an Asian elephant.
An elephant walking. Photogravure after Eadweard Muybridge,
Credit: Wellcome Library, London.
Once they realised that the current type specimen for the Asian elephant was fallacious, the scientists had to search for a different and more appropriate one. Rules issued by the International Commission on Zoological Nomenclature, the arbiter of all animal species, state that a new type specimen should first be drawn from any other examples listed in Systema Naturae or seen by Linnaeus. On of the candidates was a description of an elephant skeleton by 17th-century botanist John Ray that Linneaus cited. This is where I came in; I had previously worked with a biologist to identify when a particular specimen of Aldabra Tortoise was first mentioned (it turned out the reference was in the writings of the 17th-century naturalist James Petiver, and the subsequent solution to the nomenclature dispute involved was reported by the Wall Street Journal). Using my archival analysis of 17th-century botanist John Ray’s travel accounts and letters, we confirmed that an additional specimen, mentioned in a description by Ray (1693) and subsequently cited by Linnaeus, has been preserved as an almost complete skeleton at the Natural History Museum of the University of Florence.
Having confirmed its identity as an Asian elephant through both morphological and ancient DNA analyses, we thus were able to designate this specimen as E. maximus, the definitive type example of this species. Other evidence indicates that this elephant specimen may have been drawn and described by Rembrandt. Our paper (recently published in the Zoological Journal of the Linnean Society, the New York Times and the subject of articles in Nature News and Huffpost) is a case study of how historians of science and scientists can work together to make discoveries of relevance to both fields. Our work also shows the importance of the study of material culture and art history to the history of science.
The new type specimen for the Asian Elephant. Credit: Natural History Museum, Florence.
Anna Marie has co-authored a paper related to this talk:
Cappelini, E. et al. (2014) Resolution of the type material of the Asian elephant, Elephas maximusLinnaeus, 1758 (Proboscidea, Elephantidae). Zoological Journal of the Linnean Society, 170:1 pp.222-232.
Links:
Nature News: http://www.nature.com/news/linnaeus-s-asian-elephant-was-wrong-species-1.14063
New York Times: http://www.nytimes.com/2013/11/19/science/a-historical-elephants-new-identity.html?_r=0
Zoological Journal of the Linnean Society: http://onlinelibrary.wiley.com/doi/10.1111/zoj.12084/abstract
Cabinet of Natural History 