Absolutely this is what matters. We understand, more or less, that varieties of life connect to each other in complex webs of inter-dependent relationships that we call ecosystems. The survival of a large predator at the top of the system depends on linkages that reach all the way down to micro-organisms at the bottom. You can’t have one without all the others. There is some flexibility. A species may die or be expelled and another will move into its niche. But there will come a breaking point. The biologist Paul Ehrlich likens it to the piecemeal disassembly of an aircraft. You can go on removing some of its tiniest components – rivets from the wings, say – and for a while it will go on flying. One day, however, you will remove one too many and the system will crash. Conservation is about saving the rivets; fixing the ones that are working loose; catching some even as they fall. Maybe the Somali golden mole is still part of a working mechanism; maybe it is a missing rivet. If it has fallen, then the world is in some small way poorer for its loss. As a proxy for every other unseen or unheard-of subterranean toiler, it deserves, at the very least, a pilgrimage and a decent obituary.
CHAPTER TEN
Unpronounceable Teeth
The pilgrimage is not going to be easy. My naivety now is being worn down like topsoil in the wind, exposing hard little spikes of scepticism. I have to acknowledge that I’ve been kept back from the search by a growing expectation that it will end in failure. The world expert on golden moles, Gary Bronner, has told me that the University of Florence could not produce Professor Simonetta’s barn-owl pellet for his inspection. Now I can delay no longer. The time has come for me to beat my head on the same door. My grasp of Italian does not extend much beyond Vitello tonnato, so it takes me some time to click my way around the Università degli Studi di Firenze website and find the name of its communications supremo, Silvia D’Addario. I compose a carefully worded email in English, explaining my business and framing my questions – is Professor Simonetta still alive? Does the zoology department have the holotype? – and hit the Send button. My expectations, however, are low. Institutional bureaucracies are difficult to penetrate, and some recent encounters have wrestled me almost to a standstill. In particular, I have been sandbagged by the Natural History Museum, which suddenly wants money to answer my questions. I had asked: What was the origin of the stuffed giant golden mole, Calcochloris trevelyani, in the museum’s mammals gallery? Were any specimens in the collection shot by Roualeyn Gordon-Cumming or Frederick Selous? Not vital questions, to be sure, but historical details of particular interest to anyone fascinated, as I am, by this rare collection of bygones.
The answer to the first, I later realised, I had already found for myself (see Chapter Three), but I still wanted to know about Selous and Gordon-Cumming. The reply came from a department previously unknown to me, NHM Research Consulting, which explained that (unlike newspaper enquiries, which are answered rapidly and gratis) the museum was ‘obliged to charge’ for helping authors. Answering my questions apparently would require four hours’ work, charged at £95 for the first hour and £75 for every hour or part-hour thereafter, so I could expect a bill of £320, which VAT would stretch to £384. This saddened me not just because it makes fact-checking unaffordable but, more importantly, for the hole it exposes in the museum’s own recorded history. The statue of Frederick Courteney Selous stands, rifle in hand, in the Central Hall alongside Charles Darwin, Thomas Henry Huxley and Richard Owen. And yet, extraordinarily, the museum has no accessible record of the surviving exhibits it owes to him. To grind salt into the wound, an internal memo attached to NHM Research Consulting’s email even manages to misspell his name, ‘Salou’. Somehow I manage not to weep.
But the gloom lifts. Next day I get a friendly email from Florence. Great news! The professor lives! Silvia D’Addario has passed my message on to him, and is not asking to be paid. Like a teenager on Valentine’s Day I haunt my inbox waiting for the professor’s reply. Realistically, of course, I know it could take weeks (I had to wait nearly a month for the helpful Gary Bronner), or it might not come at all. Meanwhile, confidence plummeting, I submit finally to the realisation – which has been gradually dawning on me – that my knowledge of zoology is more appropriate to the five-year-old who fell in love with Brumas than to the white-haired author now scratching his beard. Viewing a chimpanzee, I can easily enough believe in the shared ancestry of Homo sapiens and Pan troglodytes. But how can whales be related, as I am assured they are, to hippopotamus and deer? I now find myself stuck even for an adequate understanding of what constitutes a species, never mind a genus. Reassuringly, I find I am not alone. Bigger brains than mine, including Aristotle’s and Darwin’s, have been gnawing at these questions for centuries, and certainties are as elusive as the quagga.
I find I am in dire need of expertise. With the Natural History Museum now out of my price range, I try the Royal Society, which kindly suggests the Science Media Centre, which couldn’t sound more discouraging if it tried. Their job, a woman patiently explains, is to help journalists with hot scientific news, not chase philosophical phantoms with writers who can’t even explain their books properly. Nor can she think offhand of any available expert on taxonomy – rarely the subject of hot scientific news – but she says she’ll ask around. And, glory be, she does. Within a few hours I get a call from the Centre’s mental health expert, Joe Milton, who (I thank the gods of serendipity) turns out to have a Ph.D. in taxonomy. Would I like to see his thesis, which – serendipity alpha plus! – addresses the very issues I am interested in? Precisely eight minutes after the email from Silvia D’Addario, Joe’s paper drops into my inbox.
‘Phylogenetics’ is not a word to quicken the pulse. It is exactly the kind of philological construct that would offend the plain-speaking Tim Smit, a lofty palisade against common understanding. And yet it offers the most graphic account of what we all are, where we’ve come from and where we might be going. It’s all about family trees – ‘reconstructing evolutionary history’, as Joe Milton puts it. ‘Phylogenetic trees’ are those familiar branching diagrams that show relationships between species and track them back to common ancestors. It’s as simple, and as complex, as that. Somewhere, way back in the primal fog, the golden mole and I were one.
The naming of species is as old as language. Early hominids will not have taken long to realise that the animals they saw were not infinite in their variety, though they were many, but were organised like themselves into discrete groups of approximate lookalikes, all reproducing themselves in their own image. For each of these they would have had a word or a sign. There were animals you could eat, and animals you could be eaten by. Nothing was more important than knowing which was which. As the millennia rolled by, animals were a decisive influence on human culture, subjects of graphic and culinary art, symbols of economic power and objects of worship. Animal imagery was fundamental to the ancient cultures of Egypt and Greece, and has been a rich vein of metaphor ever since. To suggest everything from undying love to bitter contempt, we liken each other to apes, asses, badgers, bats, bears, bees, cats, chicks, cockroaches, cows, dogs, donkeys, eagles, elephants, fleas, foxes, hens, hyenas, jackals, lemmings, lions, mice, monkeys, moths, ostriches, owls, pigs, puppies, rats, skunks, tigers, turkeys, whales, wolves, and even once in a while to moles. The distinction between species is so basic to the way we look at life that, outside the community of natural science, we seldom give it a critical thought. That’s a horse. That’s a cow. That’s a Rafinesque’s big-eared bat. All are immutable products of Creation/evolution, which come indelibly labelled and neatly parcelled in family groups. Or so I had always thought.
‘Taxonomy’ (not to be confused with taxidermy) is the science of labelling and organising these groups. It has a long history. Joe’s thesis traces it back to Pliny, Aristotle and Theophrastus, all of whom devised formal classifications of living things. The system of plant classification developed by Theophrastus in the third century BC, which earned him the sobriquet ‘father of botany’, remained
in use until the eighteenth century. Only then was it superseded by the work of Carl von Linné – the soi-disant Carolus Linnaeus – whose Systema Naturae, first published in 1735, marked the beginning of modern taxonomy. Linnaeus, with commendable but naive over-ambition, believed he could record absolutely everything that flew, swam, walked or crawled on earth. He was a man of deep religious conviction who believed his task was to ‘reveal the Divine Order of God’s Creation’. It might be no coincidence that it chimes so closely with the verse in Genesis (2: 19) in which Adam was commanded to do likewise:
And out of the ground the LORD God formed every beast of the field, and every fowl of the air; and brought them unto Adam to see what he would call them: and whatsoever Adam called every living creature, that was the name thereof.
Adam never finished the job; nor did Linnaeus; nor has anyone since, and I can’t find anyone who believes there is any realistic chance of the ‘Divine Order’ ever being fully revealed to Adam or anyone else. My own luck, however, continues to improve. Only two days after Joe Milton’s call, to my great and happy surprise I find myself back, gratis, in the Natural History Museum being shown specimens collected by Frederick Selous. These are not mammals, however, but insects. They are hide beetles (that’s ‘hide’ in the sense of animal skins), busy operatives in nature’s clean-up squad, which feed on the skins of dead animals. For collectors like Selous and Gordon-Cumming they must have been an expensive nuisance. They are about the size and colour of olive pips and, to anyone but an entomologist, about as interesting to look at. But never mind. The man who displays them is keen to the point of obsession. Maxwell Barclay is a premier-league entomologist, in charge of the museum’s enormous beetle collection. To spend a few minutes in his domain is to recall the Scottish biologist J. B. S. Haldane’s famous aphorism: ‘The Creator, if He exists, has a special preference for beetles.’ There is ample evidence, too, of the prescience of Haldane’s other oft-quoted remark: ‘Now, my own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose . . . I suspect that there are more things in heaven and earth than are dreamed of, or can be dreamed of . . .’
I had asked Joe to recommend an expert who would have the patience to talk me through the basic rules of taxonomy and perhaps make the universe seem just a little less queer. Max Barclay has generously volunteered. Yet again I ascend the familiar staircase past the sculpted giants – Darwin, Selous, Owen, Huxley. A Chinese girl is photographing Darwin, crouched down and shooting upwards past his huge marble boot. No one is paying any attention to his neighbours. The entomology department is a low cluttered space crammed like a wasps’ nest high under the eaves. Max Barclay is a brilliant lecturer and I form an attentive audience of one. He confirms what I have already suspected. Had I been writing a hundred years ago, the issue would have been a whole lot simpler. Then there was a broad understanding, though no clear definition, of what was meant by ‘species’, and animals were grouped into ‘families’ on the simple premiss of how closely they resembled each other. It’s a whole lot more difficult now.
Aristotle in the fourth century BC had some notion that appearance wasn’t everything – he was able to conclude, for example, that a whale was not a fish – but even Linnaeus, who had no idea about evolution, was noting similarity rather than relatedness. As Max points out, similarity is a fairly good proxy for relatedness – we all tend to resemble our families – but it is not the whole story. Darwin began to realise this, and believed the system of classification should be more like genealogy. Max explains how this works in practice: ‘Instead of a series of separate boxes into which things were thrown because they looked alike, he was working up a system that looked like a family tree, where you could trace relationships between living and fossil groups, and between different living groups.’ It is not a term that Darwin himself would have used, but this is where phylogenetics began.
It didn’t put an end to the difficulties, though. Even now, no one has come up with a definition of ‘species’ that works for all living things, though for higher organisms such as mammals there is an accepted rule of thumb, first proposed by the twentieth-century German evolutionary biologist Ernst Mayr. A species, he said, was not just a group of plants or animals that looked alike. It was, literally, a matter of breeding. According to his ‘biological species concept’, any two organisms that can breed together and produce fertile offspring are members of the same species. If they cannot breed, or can produce only infertile offspring (as in, say, a mule from a union of horse and donkey, or liger from lion and tiger), then they are of different species.
This was a significant refinement of Darwin’s theory of evolution. If a population was isolated from others of its kind, then over many generations it could diverge so widely from its cousins that it was no longer capable of breeding with them. This might happen because of different diets or feeding patterns, mating behaviour or natural selection. The next theoretical tweak was by Mayr’s compatriot Willi Hennig. It is now that another polysyllabic brute, ‘phylogenetic systematics’, enters the lexicon, though only to be supplanted by yet another, ‘cladistics’, meaning the study of ‘clades’. Just in typing the word I fear the ire of Tim Smit; another barrier to non-speakers of zoologese. Yet I find it is quite a useful one to hang on to – a good theoretical handhold. A clade is a single branch of the evolutionary tree comprising a species and all its descendants. The tree metaphor here works perfectly. Clearly the length of a clade will vary, depending on how far back up the tree you climb. Long clades may include many shorter ones – the side-branches and twigs that split from the main stem. Thus a clade may contain just a few species, or many thousands.
Hennig’s big idea was a scoring system designed to show just how closely related various species, or groups of species, actually were. It is not just a matter of counting points of similarity – that might lead you to put whales in the same clade as fish – but rather of deciding which characteristics are the ones that matter. Crudely simplified, it means distinguishing between characteristics in their most primitive, ancestral state (plesiomorphous, if you want the technical term) from the derived or advanced (apomorphous) states that have been passed down the line. It is these derived characteristics which contain the ‘phylogenetic signals’ and mark out family relationships. Simplifying further, it allows scientists to distinguish between species that are genuinely related, and those which have developed similarities – long probing snouts, powerful digging claws, dense waterproof coats, for example – simply through sharing similar environments. As an entomologist, Max takes his example from the world he knows best. ‘If you look at swimming insects,’ he says, ‘they all look very similar. They all have fringes of bristles along the legs, they all have some kind of water-repelling structures, and they all have some kind of air-carrying structures.’ Usually, however, they have developed these characteristics independently and have not inherited them from common ancestors. Lost characteristics can be just as misleading. ‘Under a Linnaean system,’ says Max, ‘flightless birds might all be put together as a group, whereas it may be that many birds that have appeared on oceanic islands have lost the ability to fly without in any way being related to one another.’
All this bears directly on nomenclature. At the time Linnaeus was devising his binomial system, most educated people in western societies would have known a smidgen of Latin. In every way, it made good sense. Having a shared academic language eased the problem of international communication. Everyone, or everyone who needed to, knew that Homo meant ‘man’, and sapiens meant ‘wise’. The sapiens bit might be arguable, but Latin speakers knew their species from their genus, and understood clearly what was being said. In the twenty-first century even scientists tend to know Latin only by rote. For this reason, and because of the increasing participation of scientists using different alphabets, it is often suggested that the ponderous and often difficult binomials should be replaced with alpha-numerical codes that would be better un
derstood by computers. It is hard to see this happening. ‘We have close to a million species already assigned Latin names,’ says Max, ‘so any attempt to change the system would require absolutely vast retrospective work, taking lifetimes.’ It is also alien to the human instinct for naming things. Not even a scientist would want to refer to number 53471c, rather than, say, Brachytarsomys villosa, or the hairy-tailed tree rat.
The number of taxonomic levels – main branches on the tree – has multiplied since Linnaeus, whose genera (plural of genus, the groups into which related species are placed) were extremely large. Again Max takes his example from insects. ‘He had the genus Papilio, in which most of the butterflies were placed. Nowadays Papilio is only a group of swallowtail butterflies, and most of the others are in different genera because people have become aware of more species, and more differences, and as we’ve got more species we’ve had to come up with more categories in order to explain those differences. Since Linnaeus, people have been chopping the genera up smaller, and introducing other levels of classification.’ At the end of my one-man seminar he lends me an undergraduate-level primer on the principles of taxonomy, which themselves seem to be evolving faster than any of the species under review. Armed with this, plus Joe’s thesis and other learned volumes from various (mostly American) universities, I begin to construct some kind of basic understanding.
The Hunt for the Golden Mole Page 19
