Roslin team helps solve elephant riddle

A recent study has revealed that Swedish naturalist Carl Linnaeus unwittingly combined two different species of elephant when he created the first description of an Asian elephant in the 18th century.

The study, published in the Zoological Journal of the Linnean Society, involved researchers from The Roslin Institute and a host of international collaborators.

Naming system

Linnaeus is considered the father of taxonomy - the system for naming all living things.

When he first came up with the name Elephas maximus, Linnaeus used two elephant examples as his reference points.

One was a five cm-long pickled foetus in a jar from the collection of one of his contemporaries, Albertus Seba. The other was a Latin description of an elephant written by John Ray, a British naturalist who studied at Trinity College, Cambridge.

Species blueprint

Seba published a thesaurus of animal specimens in 1734. His elephant became known as the Asian elephant type specimen, which scientists have used ever since as the baseline reference for identifying the endangered species.

The international team of scientists has now discovered that Seba's elephant is actually an African elephant by analysing the DNA of the foetus.

The most prominent differences between Asian and African elephants are that African elephants have bigger ears, are generally larger and have more wrinkled skin.

Museum discovery

The African elephant, Loxodonta africana, wasn't identified as a separate species to Elephas maximus until 1797 by German naturalist Johann Blumenbach, 60 years after Seba's work.

The team then tracked down the elephant described by Ray to a skeleton still on show in the Museum of Natural History in Florence.

By analysing DNA from a bone fragment, the team can confidently say the skeleton is the true type specimen for the Asian elephant Elephas maximus.

Famous elephant

The team is almost 100 per cent certain that this is the skeleton of Hansken, a female Asian elephant. She became a travelling curiosity at the time and was known to have died in Florence in 1655.

Although Ray only saw the skeleton of Hansken, the great Dutch artist Rembrandt van Rijn painted the elephant from life when he saw it in Amsterdam in 1637.

This now means that Rembrandt's paintings and sketches are the original and correct portrayal of the type specimen of an Asian elephant.

Genome insights

The Roslin Institute researchers contributed to the study through the Institute's state-of-the art genomics facilities, ARK-Genomics.

In 2013, a group of UK scientists (including those in ARK Genomics) sequenced and published the genomes of two important viruses that infect Asian Elephants, known as Elephant Endotheliotropic Herpesvirus.

The viral DNA used in the study was extracted from two infected Asian elephants.

Because of the nature of such samples, the Roslin team sequenced about 5 per cent virus DNA and about 95 per cent Asian elephant DNA.

Sharing data

As news of the UK study spread, Mr Watson was approached by the Danish researchers asking if they could see the data from the Asian elephant.

The virus researchers could never have predicted that data from the virus sequencing project would be used in such an interesting way.

This work demonstrates how important it is that researchers deposit their scientific data in public databases, where it will be used by others in ways they could never have imagined.

As well as being a great story of scientists piecing together scientific evidence spanning centuries, this is also a story about the power and importance of data-sharing.

Mick Watson