Chapter One
NATURE
WE HUMANS are one in a million: to be exact, one species among 1,392,485, according to a recent tally by the zoologist Edward O. Wilson. Those are the ones we know: estimates of the total number of living species range from five to thirty million and up, depending on how one reckons. A substantial majority of Earth's species are insects: something like 751,000 by Wilson's tally. Plants account for another 248,428, the vast majority being flowering plants (which coevolved with insect pollinators). Among the vertebrates, bony fishes are the largest group, with 18,150 species, leaving aside the 63 species of jawless fishes and the 843 cartilaginous fishes (lampreys, sharks). Amphibia and reptiles account for 4,184 and 6,300 more species; birds for 9,040, and mammals for 4,000, give or take. Not to mention invertebrates other than insects: tunicates and cephalochordata (1,273), molluscs (roughly 50,000), and arthropods (12,161). And single-cell organisms: algae (26,900), fungi (46,983), protozoa and microbes (36,560). Of our fellow vertebrates we have an inventory that is nearly complete-over 90 percent, it is estimated. On the plants and invertebrates, however, we may only have made a start. We earthlings sail through the void on an ark that is impressively biodiverse.
Biodiversity is a lively issue these days, mainly because of the number of species that are going extinct, either by natural causes, or because we space-hungry humans are destroying their habitats. Wilson estimates that perhaps 17,500 species (mostly insects) go extinct each year in tropical forests, and that we humans have accelerated the historical rate of extinction by a factor of one thousand to ten thousand. Biologists and conservationists are concerned that vast numbers of species may be forced into extinction ahead of schedule (extinction is the ultimate fate of all species) before they can be found and classified. There is concern, too, that in our ignorance we may be destroying species vital to the fabric of ecosystems on which we depend for our own survival.
Systematic biology, or taxonomy, is reputed to be a humdrum, cataloging science-a reputation entirely undeserved, let it be said. We depend on those few among us who collect, describe, name, and classify our fellow passengers on the global ark. But how exactly do we find, collect, identify, and order those millions of species? That is my subject here: not the biology or the ethics of biodiversity, but its practices and their history. Though people have always named plants and animals, the science of species inventory is relatively new, beginning with the big bang of Carl von Linne''s invention of the (Linnaean) binomial system of naming in the mid-eighteenth century. And though much has been written on theories of species, relatively little is known of the practical work that produced the empirical base for theorizing. When and how were those inventories created and made robust? Who organized and paid for collecting expeditions, collected and prepared specimens in the field, compiled lists, built museums and herbaria, and kept vast collections in good physical and conceptual order? Of these practical activities we do not as yet know much. This book is a step toward acquiring such knowledge.
The history of our knowledge of biodiversity is first and foremost a history of collecting and collections. Remarkably little has been written about the craft and social history of scientific collecting: it remains a "black box," as the historian Martin Rudwick observed a few years ago, an activity that has "barely been described by historians, let alone analyzed adequately." There are now signs of a growing interest in the history of collecting science, but it is perhaps understandable why this black box is only now being opened. Although collecting is a widespread and varied obsession, modern scientific collecting is sober and businesslike, not irregular or idiosyncratic. It is done en masse and methodically, because modern taxonomy requires large and comprehensive collections. Scientific collecting is exacting and quantitative science, as methodical and organized as taking stock of galaxies, subatomic particles, or genes. Modern specimen collections are quite unlike the romantic "cabinets of curiosities" of earlier centuries. Modern herbaria consist of cases filled with hundreds of thousands of large folios of pressed plants in paper. Museum study collections are rooms of metal boxes, each with trays of animal skins and skulls in neat rows neatly labeled-all seemingly humdrum and unromantic.
Yet the scientific visions that inspire collectors to go afield, and the varied activities that go into making large collections, are anything but humdrum. Collecting is an activity that has engaged diverse sorts of people-unlike laboratory science, which is restricted to a relatively few approved types. The botanist Edgar Anderson once did an experiment, in which he took a manila folder at random from an herbarium case (a Southwestern grass, it turned out to be), to discover the kinds of people who had collected the specimens. It was an amazingly diverse lot: a botanist on the Mexican Boundary Survey of the early 1850s; an immigrant intellectual German who had come to America in 1848 to escape political persecution; the wife of a mining engineer stationed in a remote mountain range, who dealt with the isolation by studying the local flora; a Boston gentleman, who made collecting trips to New Mexico for thirty years; a Los Alamos scientist and amateur botanist; university professors of botany; and college students who bought a second auto and spent a summer holiday collecting. "Though they have sometimes been contemptuously referred to as 'taxonomic hay' by other biologists," Anderson concluded, "herbarium specimens can be quite romantic in their own dry way."
Anderson's experiment is easily replicated: page through museums' accession lists, and you will see hundreds of names of people who contributed specimens to scientific collections, from a few odd skins to tens of thousands. Read taxonomists' checklists-which give for each species the name of the naturalist who first described it, and when-and you will glimpse a living community of collectors and naturalists stretching back 250 years, in which amateurs have the same honor and dignity as the most eminent professionals. Species collectors are as diverse as the species they collect, and no other community of scientists preserves such a deep sense of its collective identity and past. Taxonomists' elaborate system of keeping track of names, which anchors each species to the name historically first given to it and to the actual specimen first described-the "type" specimen-keeps the past forever present. All sciences have their heroes and founding myths, but taxonomy is about the only one with a living memory of all past contributors, famous and obscure.
Scientific collecting was (and is) also an unusually complex and varied kind of work. Collecting expeditions are more complex socially than anything one might find, say, in a biochemistry or gene-sequencing lab. They require a great deal of book knowledge, but also practical skills of woodcraft and logistics, as well as firsthand experience of animal habits and habitats. Modern natural history is an exacting science whose practitioners must also cope and improvise in difficult field conditions. Collecting expeditions afford an experience of nature that mixes scientific and recreational culture in a way that lab sciences never do. Collecting parties usually travel light and depend on local inhabitants for information and support, making survey collecting a diversely social experience. And because of that diversity, the identity of scientific collectors has been less fixed than that of laboratory workers. In the black box of modern expeditionary collecting, there is much of interest.
We know nature through work, the environmental historian Richard White has observed, whether it is poling canoes against the current of a great river (his particular case), or building dams across it to tap its energy, or hauling fish out of it, or diverting its waters for irrigated farming-or, historians may add, studying its hydrology and natural history. So too is our scientific knowledge of nature acquired through the work of mounting expeditions; observing plant and animal life; and collecting, preparing and sorting specimens. Historians have only recently begun to address the work of field science. And of all the field sciences, natural history survey is an exceptionally inviting subject-because the work of systematic, scientific collecting is so varied.
One is also struck, paging through scientific inventories of species, by the lumpiness of the history of their discovery. Species have accumulated steadily, but more rapidly in certain periods than in others. The first such period of discovery was the Linnaean: roughly the second half of the eighteenth century. Then, after a pause of a few decades in the early nineteenth century, another period of rapid discovery set in from the 1830s to the 1850s, which I shall call "Humboldtian," after the encyclopedic author of Cosmos, Alexander von Humboldt. Following another pause, the pace of finding and naming again quickened from the 1880s into the 1920s, by which time a substantial proportion of vertebrate species had been found and named. Since the mid-twentieth century the pace of discovery of new vertebrate species has been a fitful trickle (though lists of invertebrates grow ever longer).
These cycles of collecting and naming vary a good deal from one group of animals to another, depending on their accessibility and interest to us. Those that are large, fierce, freakish, beautiful, edible, lovable, or dangerous were inventoried early on. These include birds, carnivores, primates, and large game. Inconspicuous or insignificant creatures, or those that do not appeal-because they are slimy, cold-blooded, annoying, nocturnal, or just very good at avoiding our notice-were not fully inventoried until the surveys of the late nineteeth and early twentieth century or even later. These groups include rodents, bats, insectivores, amphibians, and reptiles.
Birds-those visible, audible, and beloved objects of watchers and collectors-were so well inventoried in the Linnaean and Humboldtian periods that the discoveries of the later survey phase show up as mere blips on a declining curve of discovery. (Fig. 1-1.) In contrast, discoveries of mammalian species display the most pronounced cyclic pattern, with marked activity in the first two phases, but the most productive collecting in the survey period. (Fig. 1-1.) The pattern for North American mammals is even more pronounced, with discoveries more concentrated in the 1890s, and the earlier peak shifted from the 1830s and 1840s to the 1850s and 1860s. Different groups of mammals show some variation in this basic pattern. Most carnivore species were described in the eighteenth century, and most of the rest in the 1820s and 1830s-we humans have taken a keen interest in our closest competitors. Rodents, in contrast, were hardly known to Linnaean describers and not fully known to science until the age of survey, when it first became apparent just how prolific of species this group has been-it would appear that the Creator loves rodents as well as He does beetles. (Fig. 1-1.) Insectivores display the same strikingly lumpy pattern of discovery; as do also Chiroptera (bats), though with a stronger period of discovery in the mid-nineteenth century and a less striking peak in the early twentieth. Discoveries of North American reptiles and amphibians also display this periodicity, though less markedly: relatively few were described before 1800, most in the 1850s, with small peaks in the age of survey and after. (Data on world species of these groups is either absent or harder to tabulate.)
These distinctive periods in the pace of collecting and describing suggest that the process of discovery was not random and individualistic, but that individual efforts were synchronized by larger cultural, economic, and social trends. This is not a novel thought. It is a commonplace (and doubtless true, as well) that early modern naturalists were inspired by the flood of new knowledge that was a by-product of the expanding global reach of European trade and conquest. And we now also know that Linnaean taxonomy grew out of the widespread interest in Enlightenment Europe in state-sponsored agricultural improvement, including schemes for acclimatizating exotic species to northern countries.
It is also clear that the early-nineteenth-century flowering of collecting and naming resulted from the greater affordability of transoceanic steam travel and from European imperial expansion and settlement, especially in the rich tropical environments of the southern hemisphere. In North America, naturalists like John James Audubon followed the military frontier into the species-rich environments of the southeastern United States. And the western boundary and transport surveys of the 1850s took naturalists like Spencer Baird into the faunally diverse and virtually unworked areas of the American West. No one has tried to map the historical geography of taxonomic knowledge onto that of imperial expansion and settlement, but I would expect a close correlation. If trade has followed flags, so also have naturalists and collectors. Access was crucial: wherever improved transportation technology and colonial infrastructure afforded ready access to places previously expensive or dangerous to reach, there the pace of discovery of new species will soon pick up.
The third of these cycles of collecting-I have without fanfare been calling it "survey" collecting-is the least well known and the most surprising. We do not think of the late nineteenth and early twentieth centuries as being a great age of discovery in natural history; but they were. One need only peruse the annual reports of national and civic museums to appreciate the enormous enthusiasm for expeditions and collecting. In the United States alone dozens or scores of collecting expeditions were dispatched each year to the far corners of the world between 1880 and 1930: hundreds in all, or thousands-perhaps as many as in the previous two hundred years of scientific expeditioning. They certainly produced as much knowledge of the world's biodiversity as any of the earlier episodes of organized collecting.
It was in the age of survey that scientists became fully aware of the world's biodiversity. In places that were explored but not intensively worked, like the American West or much of South America, faunas and floras that had seemed closed books were reopened and vastly expanded. In its first two years of operation in the western states, the U.S. Biological Survey turned up seventy-one new vertebrate species-an abundance that some zoologists found hard to credit. Inventories of vertebrate animals became so complete that subsequent discoveries of new species became media events. Why, then, has this phase in the discovery of biodiversity remained the least well known?
One reason is that collecting expeditions were mostly small and unpretentious, unlike the grand voyages of imperial exploration. Scientific collecting in the age of survey was accomplished mostly by small parties (three to half a dozen) whose purpose was to send back not exotica and accounts of heroic adventure and discovery, but rather crates of specimens. It is the dramatic explorations of the earlier periods that have caught the eye, because they were designed to catch the eye-of investors, princes, publishers, readers, chroniclers. It is no accident that the heroic voyaging of eighteenth-and early-nineteenth-century explorers-Cook, Vancouver, Lape'rouse, Humboldt, Bougainville, Murchison-is well documented and remembered. Or that historians have dwelt on the feats of American explorers from Lewis and Clark to later ventures like the Harriman Alaska Expedition, or the adventures of polar explorers, rather than on the more numerous but less flashy modern discoverers of biodiversity. Still, this imbalance needs to be set right, and I hope this book will help do that.
(Continues...)
Excerpted from All Creaturesby Robert E. Kohler Copyright © 2006 by Princeton University Press. Excerpted by permission.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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