Sea Slugs, Wombats, Microbes

An expedition to a hidden valley in Papua New Guinea in 2009 discovered a habitat whose living creatures had never been catalogued, a place so remote that even the people who live in the local highlands had never penetrated its rainforest. The explorers came across an unnamed species of woolly rat that was not afraid of human beings, probably because it had never seen any before: the wariness that we inspire in the animal kingdom above the level of the earthworm had yet to reach this remote spot. The entomologist George McGavin’s eyes still light up when he describes the strange insects he recognised there as species distinct from all those previously known to science. As well as esoteric specialities, there were huge beetles and an ant that had evolved to resemble a spider.

There is a special wonder in being the first person to identify a new kind of organism. It is partly to do with expertise: the discoverer has to know his way around the vast and complicated catalogue of living creatures before he can claim to have found a new species. But there is also a sense of revelation. The feeling is captured in the breathless enthusiasm of Alfred Russel Wallace’s notebooks, here describing a butterfly: ‘I trembled with excitement as I saw it come majestically toward me & could hardly believe I had really obtained it till I had taken it out of my net & gazed upon its gorgeous wings.’ Wallace was the first to identify some of the most flamboyant productions of evolution, the birds of paradise, and everywhere he went the delight he felt at what he saw mattered just as much as any thought of scientific ownership. He knew, however, that before such pleasure could be communicated, the species under examination must be given a scientific name.

The ritual of identification has rules. For example, no animal or plant has been allowed more than one scientific name since Linnaeus established the system of applying first a generic and then a specific name in his Systema Naturae two and a half centuries ago. This form of shorthand was a blessing, replacing as it did Latin descriptions that were often wordy and elaborate. There was now a hope that all of nature could be parcelled up, species by species, based on anatomy alone. But the Linnaean system lent a special urgency to the quest to be the first discoverer, the person whose name would for ever be appended to the species. Linnaeus’s own great contribution is reflected in the fact that most plants and animals in Europe still bear his initial: his author abbreviation is simply ‘L’.

In the heady days of species-hunting the race was always on to find something new and preferably spectacular, and to get the credit for it. Richard Conniff’s entertaining book commemorates this contest, particularly during the 18th and 19th centuries. The seekers sought out challenging, unexplored places likely to yield rich taxonomic rewards, notably Amazonia and the Dutch East Indies. Many of them sacrificed their lives for a beautiful mollusc or orchid, which, if they were lucky, still carries their name. Stamford Raffles of Singapore is commemorated in one of the most extraordinary ‘vegetable productions’ on earth, the parasitic Rafflesia (its gigantic flower, the largest known, stinks of rotting meat). One wonders whether that memorial was worth the death of four of his children from dysentery and similar illnesses. It seems that most of Conniff’s heroes spent a large part of their lives shivering from bouts of malaria or removing parasites from their flesh with tweezers.

Long after the collections had been made there were yet more dangers involved in getting them back to an institution where they could be formally named. On 6 August 1852, Wallace’s ship Helen burned in the water, taking with it all of his precious Amazon collections. ‘How many times,’ he wrote later, ‘when almost overcome by the ague had I crawled into the forest and been rewarded by some unknown and beautiful species!’ How could he bear their loss, let alone set out again soon afterwards on the hunt? At this point I hesitate between thinking of him as mad or heroic. Something like the buzz of discovery that McGavin and his colleagues can still experience in Papua New Guinea must have sent Wallace to Indonesia, where he founded the modern discipline of biogeography and famously anticipated Darwin. Even after the specimens finally arrived home and were incorporated into museum collections, dangers remained: hard-won skins could be consumed by pests and although arsenic preparations helped, they also helped their users to an early grave. It was a fraught route by which to arrive at what museums like to describe as their ‘permanent’ collections.

In the 19th century there was more to taxonomy than listing discoveries. It still seemed conceivable that scientists could get to know every single species. Make enough collections and the entirety of creation could be revealed. It didn’t affect the quality of the taxonomy whether or not explorers believed – as most did – that all species had been created by the Almighty. The Jesuit Père David, who explored China in the 1860s, was propelled by his quest for God’s wonders, and careless of personal hardship.

Exploration was by no means confined to rainforests. Conniff is particularly good on the early history of species ‘bagging’ in North America. Every ornithologist will know the name of John James Audubon, but there were many other impressive pioneers in recording life on the continent. I hadn’t realised the extent to which Thomas Jefferson, for example, engaged in speculation about the affinities of fossilised mammoth bones that had turned up in West Virginia: there are even species named jeffersoni. But taxonomy also attracted charlatans and deranged enthusiasts. Constantine Rafinesque, according to Conniff a ‘brilliant crackpot’, is said to have submitted a paper for publication describing a dozen new species of thunder and lightning. He scooted across America, trying to get his name for a species into print first, even if he had not actually examined it. In the process he wrongfooted many more scrupulous and scholarly systematists and, surprisingly, some of the ‘wild effusions of a literary madman’ fulfilled the rules of nomenclature. Conniff doesn’t mention that Rafinesque’s name is celebrated in Rafinesquina, an ancient but rather dull and common fossil brachiopod shell.

There were some who challenged the need for all this naming, but the utility of precise taxonomy became obvious when the malarial parasite was linked to the mosquitoes whose attentions had been such an inconvenience to Wallace and his fellow explorers. This is one of the great detective stories in medicine; the identification of mosquito species and their parasites, which could be passed on to human hosts, played a crucial part in pushing back the disease. Suddenly, the capacity to distinguish insects by the tiniest differences in wing venation or ‘hairs on legs’ became much more than a diverting hobby for eccentric naturalists: it was a lifesaver. Once mosquitoes were banished, swampy tracts of Italy that had been uninhabitable became desirable suburbs of Rome. Future species hunters would never again have the nightmare of recurring fever; instead, quinine and mosquito nets were packed alongside spirit jars and labels. A utilitarian argument has been used ever since to justify species hunting: who knows if this small weed might not contain a cure for cancer?

There is an important difference between the species hunters and taxonomists who delight in nature’s richness, and those who seek out its underlying laws. Nowadays, we call the latter evolutionary biologists. Good scientists though some of them are, they sometimes find the profusion of nature almost an embarrassment. Many of the more extreme reductionists would, it seems, prefer the wild to consist of no more than three interacting species so that it could better approximate to their theoretical models. Conniff’s excellent chapters on early species hunters are interrupted by an account – yet another account – of the Darwin-Wallace story. But Wallace is not now the forgotten figure he may once have been. He was a much more immediate writer than Darwin and his seminal contributions to animal distribution studies are acknowledged by most academics. More important, after his barnacle studies, Darwin was no longer really a ‘species man’. He became instead what he famously described as ‘a machine for generating hypotheses’. Cooped up in Down House, he didn’t go back into the field overseas, contenting himself with his prolific correspondence with those who did. Not so much a describer, rather an explainer: the first evolutionary biologist. Wallace always relished nature’s profusion, and loved exploration. It might have been better for this book to have left to one side the familiar story of the first, compromised Darwin/Wallace statement of the theory of evolution by natural selection.

Contrarily, one of the most vituperative priority battles in the history of taxonomy unaccountably makes no appearance here. Edward Drinker Cope and Othniel Marsh spent much of the latter part of the 19th century trying to outsmart or even out-cheat each other in the pursuit and naming of the dinosaurs that were then being unearthed across America. They used every trick imaginable to get hold of specimens, name them and publish the findings before their rival could. Cope wrote more than a thousand papers in his mad rush for priority. Marsh and Cope each described the same species several times, making for nomenclatural nightmares that are still being sorted out. The whole thing was made more complicated by the fact that dinosaur fossils can be named from just a few bones, so that different bits of the same species could easily get a different label. The spirit of Cope and Marsh lives on in China. Recent important fossil discoveries in 520-million-year-old Cambrian strata in Yunnan Province have been chased by at least three scientific teams, who pay peasant excavators for their rarer finds. The finders’ names are still jostling for priority.

The most significant dampener on the rush to identify species may well have been the realisation that the task of their scientific description was Sisyphean as the numbers of species on earth moved into the millions; the likely total is still being debated. We probably know almost all the birds, but beetles present a taxonomic Everest of which the foothills have hardly been climbed; as for the microbes, their numbers multiply as the molecular techniques to study them become more sophisticated. Then there is what Conniff describes as ‘the commonplace modern attitude that if you have seen one tree, or sea slug, or wombat, you have seen them all.’ Can it be that the taxonomic sensibility has been snuffed out? Do we have to invoke the utilitarian argument about cancer cures for people to care about the discovery and protection of nature?

Unnamed creatures as remarkable as any 19th-century discovery are still lurking out there. A current programme of exploration of the deep sea floor has revealed an alien world of vampire fish and ghostly squid as fantastical as anything whooping through the trees in Amazonia. The depths of Lake Baikal are a treasure trove of arthropod novelties, and when the people who work there describe their finds the thrill of discovery is obvious. The internet has stimulated a revival of the gifted amateur, and one can only hope that Conniff’s fine book may help to create a few more Alfred Russel Wallaces.