A COUPLE of years ago, Stylianos Chatzimanolis received a box of insects in the post. The package came from London’s Natural History Museum: Chatzimanolis was updating the classification of an obscure group of beetles and – as taxonomists often do – had asked to borrow some specimens.
The beetles had been collected long ago but never formally described. They were just roughly classified as members of the same genus, Trigonopselaphus. But when Chatzimanolis opened the box, he could see that one of the 24 specimens clearly didn’t fit in. Long-bodied, with a segmented, sinuous abdomen, it was much larger than the others and had a distinctive, iridescent head.
As he read the beetle’s yellowed, handwritten label, he realised the specimen had been collected in 1832 in Argentina by Charles Darwin during the voyage of the Beagle. Somehow it had never been described. It was stored away unnamed, then disappeared into the museum’s vast beetle collection. Finally, after 180 years in limbo, Chatzimanolis gave it a name: Darwinilus sedarisi, in honour of Darwin and the writer David Sedaris, whose audiobooks he listened to while writing the description in his office at the University of Tennessee.
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The rediscovery of Darwin’s long-lost beetle was a remarkable stroke of fortune, but the wider story – of a new species being found in a museum collection – is surprisingly common. More than 1000 new beetle species are described each year from the Natural History Museum’s collection alone.
And it’s not just insects that are found languishing in museums: new species of snakes, fish, amphibians, reptiles, snails, spiders, crustaceans and even large mammals have all emerged from the archives. Museum collections are now at least as important as field expeditions for discovering new species. By some estimates, 75 per cent of newly described species are already part of a collection somewhere on the planet. But with museums worldwide falling victim to neglect and underfunding, these vital sources of biological knowledge are in peril.
For centuries, scientists have been describing and classifying the natural world. But despite their endeavours, we have barely scratched the surface. In 1758, when Linnaeus published the tenth and definitive edition of Systema Naturae, around 10,000 species had been named. He considered this to be fairly comprehensive – but he was wrong. By most estimates, there are about 10 million species on the planet; fewer than 2 million of them have been named. Around 18,000 new ones are described every year. At that rate, it would take centuries to name everything.
Some species are discovered the old-fashioned way: intrepid biologists trek into some unexplored tract of forest or swamp, collect specimens and send them home. But you don’t have to go into the wilderness to find a new species. In 2015, entomologists at the Natural History Museum of Los Angeles County announced the discovery of 30 new species of flies captured in city backyards. David Ebert of the Pacific Shark Research Center in California has named 10 new species of shark from specimens he found for sale in a single Taiwanese fish market.
Museums offer an even richer vein of new species. They sit in neglected and forgotten corners, linger in basements and storage cabinets. Their labels turn yellow and fade. The person who collected them dies. Surrounded by millions of other specimens, they become lost in time – until someone opens a drawer or takes the lid off a jar and sees something unknown inside.
Beetlemania
When you visit a large, established museum, it is impossible to get a sense of the immense size and breadth of the collection that sits beyond the public spaces. The Natural History Museum has 10 million beetles that fill 22,000 drawers. The Smithsonian National Museum of Natural History in Washington DC has 30 million insects. The American Museum of Natural History contains more than 250,000 bats. The herpetology collection at the California Academy of Sciences in San Francisco has 300,000 reptiles and amphibians. At the Duke University herbarium in North Carolina, the moss collection alone is made up of more than 160,000 specimens. All told, US natural history collections contain an estimated 1 billion specimens. Across the world, that number probably exceeds 3 billion. In short, there is far too much material for taxonomists and curators to assess, identify and name.
And it keeps on coming. Collectors in the field capture specimens and then prepare them for their afterlife. Mammals and birds are skinned, gutted and placed in a case filled with carnivorous beetles, which strip the flesh in hours, leaving behind a meticulously cleaned skeleton. Insects are pinned; fish and amphibians are dunked in preservative. The collectors take tissue samples, add location data and dispatch specimens to their home collection, where – in theory – they are identified, classified and stored away.
If a specimen is found to be new to science, it is designated as the holotype: the one upon which the description is based. A new branch sprouts on the tree of life. As with all holotypes, it is clearly marked with a red tag to denote its primacy and locked away. A holotype is irreplaceable and so is subject to the highest security. The search then begins for paratypes: additional specimens that taxonomists need to fully describe and define a new species.
But identification and classification is a painstaking process. The time that passes between the collection and description of a specimen is known as its shelf life. The average across all orders of organisms is about – although almost a quarter of new species found in collections have waited more than 50. Even when a specimen is examined, it is often misidentified and wrongly named. In 2015, researchers at the University of Oxford and the Royal Botanic Garden Edinburgh, UK, assessed the accuracy of plant collections in 21 countries. More than half the specimens they examined had been given the wrong name. Between 1970 and 2000, the number of tropical plant specimens in herbaria doubled, but .
Sometimes, important specimens are merely misplaced. That’s what happened to Darwinilus sedarisi. “The Natural History Museum is not a small place,” says Chatzimanolis. “They have millions and millions of specimens. If you misplace something, the chances of finding it there again are near zero.”
“There are thousands of unrecognised species hiding in our collections”
But miracles do happen. In 2008, University of Copenhagen entomologist Alexey Solodovnikov was at the museum looking through unsorted beetles. After briefly inspecting Darwin’s specimen, he moved it, tentatively and incorrectly, into a box with other Trigonopselaphus beetles. And there it stayed, until Chatzimanolis opened the box.
Location information can often be wrong too, or so vague as to be useless. And in plenty of cases, specimens aren’t identified at all. A faded, handwritten label might bear the tantalising annotation “novel species?”. Or simply “nov. sp.?”.
This is a problem worldwide. But it creates rich, virgin territory for intrepid taxonomists to explore.
One such explorer is Matthew Buffington, an entomologist at the US Department of Agriculture. “When I go to the Natural History Museum, I’m not too interested in what their identified stuff is. Usually it’s wrong. The labelling is somewhat questionable. The locality data, a label that says ‘Argentina, 1990’ – scientifically, that’s almost a useless specimen.” Instead, he heads for the drawers and cabinets holding specimens that have no names. “The real fieldwork, the moment of discovery, all takes place in what we call the unsorted material,” he says. “Most of us who cruise around looking at collections, that’s where we’re spending our time, because we know there are undescribed things there.”
Adam Wall, assistant collections manager for crustaceans at the Natural History Museum of Los Angeles County, agrees. “I guarantee you there are hundreds if not thousands of yet-to-be recognised species essentially hiding in our collections,” he says. “They’re just chock-full of undescribed species.” Kristofer Helgen at the University of Adelaide in Australia says he’s aware of at least 50 unknown species of mammal waiting to be classified in museum collections.
In 2003, he discovered one himself. He was visiting the Field Museum of Natural History in Chicago to examine the skulls and skins of a group of small, raccoon-like mammals called olingos, which live in the cloud forests of Central and South America. But when he pulled open a drawer, he stumbled on something totally different. “I knew instantly they weren’t olingos,” he says. “They’re nothing like anything anyone has ever described or put a name on.” After a decade of investigation, which included an expedition to Ecuador to find the animal in the wild, Helgen named the species the olinguito (Bassaricyon neblina). The holotype was collected in northern Ecuador in 1923, but misidentified as an olingo, filed away and forgotten. “It’s a perfect illustration of how something can hide in plain sight,” he says.
There’s plenty more where that came from. Earlier this year, Helgen was part of a team that unveiled a , the Skywalker hoolock gibbon (Hoolock tianxing). The animal lives in the tropical forests of Myanmar and southern China, yet the holotype was discovered in New York City, in the American Museum of Natural History. It was collected in 1917, but misidentified.
However, as the importance of museum collections grows, they are increasingly threatened – by neglect, by lack of funding, by dwindling staff and by natural disasters. In April 2016, a fire destroyed the National Museum of Natural History in New Delhi – the largest and most important natural history collection in India, containing who knows how many undescribed species. Five years earlier, the Tohoku earthquake damaged numerous museum collections along the east coast of Japan. For weeks afterwards, curators managed an army of volunteers who cleaned mud from thousands of specimens by hand.
More insidious threats can be devastating too. In the tropics, the humidity invades everything, degrading specimens until they rot. An infestation of beetles can eat a collection to oblivion.
Many collections also have to contend with chronic under-resourcing. In recent years, a lot of institutions have seen drastic reductions in funding, and the number of taxonomists and curators has declined. In 2001, the Field Museum had 39 curators; today, there are 21. The National Museum of Natural History in Washington DC has seen the number of its curators fall from a high of 122 in 1993 to a current low of 81. In the past, many larger institutions had a team of curators working in each discipline: three or four mammalogists, a couple of ichthyologists, several entomologists. Frequently, these have been replaced by one overburdened collections manager – or nobody at all.
To add insult to injury, specimens go missing from museum collections all the time. Even holotypes occasionally go walkabouts. Sometimes an entire collection disappears. At a smaller institution, or in an academic department, an expert in a particular group will retire or die and leave behind thousands of specimens. Occasionally, these orphaned collections are adopted by larger institutions. Often they’re not.
All of life is here
For many on the front line, it feels as if natural history collections have been set adrift. The public often think they are quaint, Victorian throwbacks: dusty, dimly lit and no longer useful. But they are more important now than ever. They provide an indelible taxonomic record of life on Earth, and life on Earth is changing. By some estimates, current rates of extinction are a thousand times higher than the natural background rate. For some species, a few specimens in natural history collections are the only examples that exist.
Collections have multiple practical uses too. They allow researchers to understand the effects of processes such as climate change, by comparing the species present in a particular region across time. Specimens can help pinpoint the introduction of invasive species and changes in bird migration patterns. They can even allow epidemiologists to track the outbreak of viruses that jump from animals to people, such as Ebola and Zika.
Most important of all, conservationists can’t protect a species until they know it exists. “If it turns out that what you thought was a single, widespread species actually consists of 25 species, each with a very small range, then your whole strategy for conserving that genetic heritage is very different,” says James Hanken, director of the Harvard University Museum of Comparative Zoology.
Sometimes, a new species is discovered in time to put a conservation strategy in place. Other times, not. Since naming Darwinilus sedarisi, Chatzimanolis has found just one more specimen, broken and badly damaged, at the Museum of Natural History in Berlin. In the wild, though, its habitat has been impacted by human activity. The beetle is probably gone for good. All we have left are specimens pinned in boxes.
This article appeared in print under the headline “Behind the scenes at the museum”
