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5

Flaming Front

To clear the forest’s dark impervious maze

The half-starv’d Indian [Aborigine] lights a hasty blaze

Then lifts the Torch, and rushing o’er the Strand

High o’er his head he waves the flaming Brand

From Bush to Bush with rapid steps he flies

Till the whole forest blazes to the skies …

—THOMAS MUIR, “The Telegraph: Consolatory Epistle” (c. 1790s)

Our cots we fence with firing

and slumber when we can

To keep the wolves and tigers from us

in Van Diemen’s Land.

—ANONYMOUS BUSH BALLAD, “Van Diemen’s Land”

THE REVOLUTION THAT SHOOK Pleistocene Australia was part of a global reformation. The world ocean rose and fell. Ice sheets on the scale of continents formed and disintegrated. Climates reversed from glacial to interglacial and back to glacial again in rapid order as though the Earth were being swept by slow-moving planetary storms. A massive wave of extinctions—the most comprehensive since the great Cretaceous extermination—visited the world biota. It was within this context, within the biotic center of the Pleistocene, that the genus Homo emerged. With the arrival of humans, the eccentric, the protective isolation of Old Australia broke down. Well before humans brought other, allied species to the island continent, they carried and distributed fire.

Even for a fire planet like Earth, humans are special. For the first—and probably the only—time an organism seized control over ignition itself. That moment was unique, unprecedented, and it is unlikely that Homo will ever allow another species that experience. Thus the elaborate rituals by which human societies preserve fire have an allegorical dimension. Once acquired, humans would never allow fire to be extinguished. Fire remained as part of Homo’s biological heritage, and around it much of human culture has evolved. Take fire away from a human society and its technological base would be devastated.

The onset of domestication and the acquisition of fire were reciprocal processes: if Homo domesticated fire, it was equally true that the nurturing of fire advanced the domestication of Homo. The hearth fire became the practical and symbolic center of human society; it defined family, group, nation. The hearth expanded to become a ring of fire that shielded humans from the dangers of the night. It divided the world of the human from that of the nonhuman. As the ring moved outward, it projected human will and imprinted a human touch. Humans advanced like a flaming front, steadily expanding their protective, transforming, magical ring of fire.¹

RING OF FIRE

Again and again, as conditions waxed and waned, new species of Homo incubated in Africa, then dispersed to all the contiguous lands accessible to them. The critical range was apparently the chronically disturbed rift valley of eastern Africa. Near here the other great primates flourished; here the fossil record, though always tenuous, is best preserved; here climate and biological potential carved savanna from forest on a landscape abundantly fired by lightning and volcanics. Here it appears Homo emerged as a distinct genus some 2 million years ago.

The event was long in coming. During the Miocene anthropoids had colonized the Gondwana tropics in Africa, Eurasia, and South America. The ancestral great apes, Pongidae, thrived only in Africa and Eurasia, however, appearing about 15 million years ago. Hominidae arrived probably 5–4 million years ago. The hominid alliance included Australopithecus and, perhaps 2 million years later, Homo; some specialists would accept also Ramapithecus, which is ancestral to the australopithecines, and the closest of the great apes, the chimpanzee and the gorilla. While the precise evolutionary relationships between the major members of the alliance are unclear, a reasonable guess is that the earliest hominid, Homo habilis, broke free of Australopithecus around 2 million years ago. Within a few hundred thousand years—that is, by 1.7–1.5 million years ago—it was replaced as the dominant hominid by Homo erectus. H. erectus thrived until 200,000 years ago, and perhaps as recently as 100,000 years ago, when Homo sapiens claimed supremacy.²

Among the critical differences between H. habilis and H. erectus were a dramatic growth in brain size, more sophisticated stone tools, and the acquisition of fire. With firemaking, the new hominids merged two evolutionary trends, one trend common to many genera and one specific to Homo. To the fire adaptations among Earth’s flora and fauna, hominids added others. To the human capacity to make and use tools, they contributed a new implement. Toolmaking was a necessary preadaptation to fire, for without the capacity to grasp tools, humans could not apply or remove firebrands. Likewise, the capacity to start fires by percussion or drilling, as distinct from the much older ability to preserve fire, surely derived from experiments in tool manufacture with flints, bone, and wood.

Yet fire was not mandatory to hominids. Australopithecus apparently wandered widely throughout Africa and southern Eurasia without fire, as did Homo habilis, who possessed some stone tools but lacked fire. Few flora are utterly helpless before fire; few fauna recoil in terror from flames. Domesticated dogs and livestock will lie or stand beside humans as they, too, stare into flames. The Philippine tarsier, it is reported, will gather around a quiet fire and even pick up coals (from which practice comes its scientific name, Tarsius carbonarius). Full-blown flight occurs only before rare conflagrations, a reasonable response. When early hominids used fire, they mimicked processes in nature—hunting along fire fronts as did other predators and raptors, scavenging among burned areas, slashing and burning not unlike winds and lightning. But once established, Homo’s fire practices revolutionized human society and its relationship to the natural world.

Homo erectus became a fire creature. The hearth granted heat, light, power. Cooking redefined the availability of foods, rendering edible many seeds, meats, and roots otherwise too tough, poisonous, or unpalatable to consume; anthropogenic fire began to slow cook the Earth. The reformation of diet made possible a reformation in dentition, which allowed new patterns of facial muscles and a loftier skull. A controlled flame fire-hardened wooden spears and gave flint a stony tempering. Later, fire made possible a primitive metallurgy and ceramics. Humans used fire to fell trees, to carve trunks into dugout canoes, even to mine. The hearth fire expanded the realms of climate accessible to human existence. The controlled flame was a technology of incredible, almost universal power.

The warming hearth similarly reconstituted society as it drew together bands of hominids and restructured domestic relationships. It defined a family or a group; it defined Homo. Yet it was a precarious presence, in need of constant attention. Humans knew how to capture and preserve fire long before they knew how to make it. Even when the skills and equipment were present to ignite fire almost at will, fire was preserved in slow matches or coals. The hearth fire acquired ceremonial, sacred properties, and was never to be allowed to extinguish; the role of fire keeper was among the earliest of human roles and institutions. The preservation of fire, in turn, demanded shelter, which fire often helped provide. If windbreaks shielded flames, so too could fire hollow large trees into habitable cavities, and smoke could drive off bears, sloths, and saber-toothed tigers that would otherwise compete for caves. Even without roofs and sides, fire itself made a kind of cave of light and heat. Fire’s brilliance prolonged the day, extended the realm of human activity, even apparently altered the circadian rhythms that governed sleep cycles. With fire, humans—hunted by so many nocturnal predators—could quell some of their fears of the night. Within their protective ring of fire they could work, eat, talk, and sleep.³

That fire ring segregated their cultural world from the natural environment around them. For such creatures there could be no innate fear of fire. Any member who instinctively pulled back from flame would be automatically excluded from the human group. To pass through the ring of fire—to live within it—was, in practice and symbol, the mark of humanity. Around their evening fires they told stories, related myths, danced to rites; fire induced a kind of hypnotic, contemplative reverie. Though sacred, fire remained peculiarly human—a gift (or theft) from the gods, but not often a god itself. Still, the ability of humans to use firebrands and the capacity of so many lands to receive fire expanded the ring of fire from hearth, cave, and hollowed bole outward. It remade the natural world into a humanized world.

Broadcast fire was important for hunting and habitat, for foraging and the early domestication of flora and fauna. Fire could drive game—and most birds and mammals valued as game by humans thrive in fire-prone biotas. Smoke flushed game out of nests and caves. Burned areas were prime sites for scavenging and tracking; the sour odor of charcoal even suppressed most smells, an advantage for humans whose sense of smell was crude. Burning maintained such preferred habitats as savannas and forest-grassland eco-tones. Broadcast burns temporarily swept away cover and made travel easier. With torches humans could hunt fish and wildlife at night. Burning favored many of the tubers, nut trees, forbs, and other plants useful to a diet of foragers and exposed them to harvest. By hunting large browsers and grazers, hominids upset fuel complexes, and had they not fired sites, those fodder-rich biotas would have shifted toward scrub and woodlands.

Early hominids answered a wanderlust that urged even Australopithecus as far as Java by 2 million years ago, H. habilis throughout Africa and possibly into Southeast Asia, and H. erectus from an African hearth to Europe, China, and Java along what was becoming a virtual pilgrimage route for peripatetic hominids. But this time hominids had fire, and their progress through mountains and plains resembled a flaming front, a broadening ring of fire, feeling its way into grasses, brush, bog, and forest, here flaring and there dampening, but always widening like fiery ripples spreading from a central ignition in Africa.

Not surprisingly, much of the confirming evidence for erectus is fire. There is a hearth in east Africa dated at 1.7–1.5 million years before the present. Cave fires sustained by H. erectus have been dated at over a million years old in France (Escale Cave), Spain (Torralba-Ambrona), and perhaps Hungary (Vértesszöllös); at Choukoutien, China, charcoal remains date from approximately 450,000 years ago; in Sangiran, Java, from perhaps 1 million years ago. The site at Torralba is particularly interesting because the distribution of charcoal and mastodon bones suggests that fire may have been used actively in the hunt, not merely for cooking afterward. While bones and charcoal give somewhat different dates, some older and some younger, they appear together, hand with brand.⁴

The pace accelerated with the appearance of Homo sapiens. Fossil records suggest an emergence between 200,000 and 100,000 years ago. Genetic records, encoded in DNA, recommend a more recent appearance, perhaps less than 100,000 years ago. Again, the source is Africa, and again another ring of fire radiated outward, a rhythm of anthropogenic burning that added to the other disturbances of the Pleistocene. The timing of its appearance, however, involves sparse evidence and complicated calculations. Migrations occurred not once but several times; new arrivals likely interbred with old residents; fire had to interact with other environmental parameters, particularly with a climate that often dramatically reversed itself within a span of centuries, a transformer that charged biotas into a kind of alternating current. That human procession, however, marched by torchlight.

By 40,000 years ago, H. sapiens had spread anthropogenic fire across Eurasia and the great land bridges—the Sunda and the Sahul—that joined Indonesia and Greater Australia to Southeast Asia. The colonization of the New World followed, synchronized with the ebb and flow of northern ice sheets that elevated Beringia from the seas and kept open a steppe corridor through central Alaska and along the eastern flank of the Rockies. Although some artifacts suggest an entry around 30,000–25,000 years ago, the substantive, confirmatory caches document another wave, or waves, that arrived in the New World with the waning of the Wisconsin glaciation around 11,000 years ago. Within 1,500 years, these new pioneers—big-game hunters—reached the southern tip of the Americas, Tierra del Fuego; the land of fire. The colonization of more remote islands occurred later, in historic times and by boat rather than by land: Greenland, by Inuit and Norse; the Atlantic islands, by Europeans from the tenth to sixteenth century; the Pacific Islands by Melanesians and Polynesians, from 1300 B.C. to around A.D. 900. Anthropogenic fire reached Antarctica only on the eve of the twentieth century. By then Homo’s ring of fire had encircled the Earth many times over.

CARRYING THE FIRE

Just when anthropogenic fire appeared in Australia is unclear. There is evidence for an abrupt, dramatic surge in burning around 40,000 years ago, coincident with the first documented fossils of Homo. But there are tantalizing suggestions that humans and their fires may have arrived much earlier. Homo erectus reached Java more than a million years ago; Homo sapiens swarmed over Asia about 100,000–70,000 years ago. Whether the venerable Wallace Line was as effective a barrier to humans as to other Asian mammals is unknown. For 50 million years Wallacea—a cluster of volcanic islands and deep-water channels—had segregated Southeast Asia from Greater Australia. Only mice, rats, and humans made the passage. One other migrant, the dingo, almost certainly traveled with humans, along a route that avoided Wallacea proper.⁵

The strength of the Wallace barrier flickered inconstantly. Over geologic time, it depended on systems of volcanic arcs, which varied according to plate mechanics. Over the span of the Pleistocene, its geography rose and fell with glacial tides. During glacial maxima, as ice sheets abstracted more and more of the world ocean, sea level fell, and what had been broad seas became channels. Even at its minima, however, a journey across Wallacea demanded at least eight voyages, and never fewer than fifty kilometers of sea had to be spanned. Two major routes seem probable, a southern route through Java and Timor and a northern route through Borneo.

Evidence for early human presence, however, is indirect. During the glacial epoch of 150,000–100,000 years ago, there is a geologic record of deposition, debris flooding, and vegetation change—from rainforest to scleroforest—and charcoal that has been interpreted as a possible consequence of human activity. There is, it appears, a pulse of change that subsequently settles into a more routine, but altered landscape. During this initial outburst, burning increased fourfold. It is suggested that early humans might have followed the Sahul savannas, then gradually encroached by fire into more heavily forested lands as seasonal and secular drought permitted. Once established, they could have used fire to keep open major corridors and hunting sites against reclamation by rainforest.⁶

Another line of evidence concerns the Pleistocene remains of hominid skulls. While the skulls all differ from those typical of contemporary Aborigines, they fall into two distinct groups, “robust” and “gracile.” The robust shape is the more ancient, as close to H. erectus as to H. sapiens. One speculation is that it represents a hybrid or intermediate type such as Homo soloensis, which flourished in Java between 300,000 and 100,000 years ago. Or it may represent an earlier subspecies of H. sapiens, analogous to the Neanderthal of Europe. Either way the hominid possessed fire, and if the geologic record prior to the last glacial epoch expresses a pulse of anthropogenic activity, then the robust Australian was the likely agent. There are, however, no sites that directly date Homo to these early times.⁷

The gracile Australian arrived later, probably crossing into the Sahul during the last glacial maximum, around 55,000 years ago. By 40,000 years ago this hominid had spread to both southwestern and southeastern Australia. From then onward the archaeological record is firm. Both robust and gracile skulls coexist, and probably there was interbreeding. Eventually the gracile form predominated. The modern Aborigine—remarkably varied in physical traits—is the evident outcome. By 20,000 years ago the Aborigine had colonized the perimeter of Australia, including Tasmania (then joined to the mainland), and had penetrated up rivers to the freshwater lakes of the interior. The climate overall was wetter, colder, and probably less intensely seasonal than today. Only the most arid core, small offshore islands, and the higher mountains of the southeast were not fully settled. As the last of the Pleistocene glaciations (c. 30,000–12,000 years ago) waned, sea level rose. At its minimum (roughly 16,000 years ago) sea level had plummeted 150 meters below current values. As the world glaciers receded, however, the seas returned. By 14,000 years ago the resurgent ocean submerged most of the Arafura plains that bonded Australia to New Guinea. By 12,000 years ago, the relentlessly rising seas permanently separated Tasmania from the mainland. By 8,000 years ago, Australia and New Guinea became separate islands. Two millennia later, the sea level stabilized and the littorals claimed approximately their present positions.⁸

The rising seas did not end all human migration to Australia. The earliest migrants had depended on watercraft; but these were primitive affairs, little more than log rafts, probably of Asian bamboo. With time the seas to the north, west, and east of Australia became the scene of maritime cultures, and Australia was visited many times, intentionally or accidentally. Around 4,000 years ago, a new stone toolkit of delicate flakes arrived; so did the dingo, macrozamia cultivation, and new styles of hearths. The likely origins are the Indian subcontinent, whose inhabitants exploited the new technology of seacraft and monsoonal winds to bypass the Wallace barrier. The introductions quickly spread across Australia. The eastern mountains, in particular, experienced an order-of-magnitude increase in human activity. Polynesians must have visited the Australian coast during their voyages. In the seventeenth century Malaccan traders and trepang gatherers began routine visits to the northern coastline of Australia, a practice that continued, intermittently, until the twentieth century. The impact of Malaccans and Polynesians, however, was minor: the patterns of Aboriginal life had been laid down over the preceding millennia, an existence that more or less bypassed the Neolithic revolution which was, on other continents, transforming foragers and hunters into herders, farmers, and urbanites. The phenomenal isolation of Australia continued until European colonization in the eighteenth century, and when it again broke down, the rate and magnitude of change proved almost catastrophic.⁹

If it is not clear just when Homo first arrived in Australia, neither is it obvious what routes early humans used to disperse throughout the continent. One theory argues for a coastal colonization. Watercraft were essential to make it to the Sahul, and rafts could continue to carry humans around the resource-rich perimeter. Movement inland followed rivers and clustered around the many lakes that splashed across Pleistocene Australia. Another theory suggests a more interior route, exploiting the watered savannas that wound between the desert core and the more heavily wooded coasts. In this instance, the rivers would lead to the well-lardered coasts and lakes; and from the grassy plains humans could gradually claim the forested bush and mountains. Obviously both patterns could coexist. What seems indisputable is that by 40,000 years ago humans had colonized the major landscapes of Australia. The more inhospitable environments—cold glaciated mountains, arid stony deserts—did not come under year-round human influence until the past few millennia. Whether or not other humans were on the scene, the newcomers wrote a separate record, one preserved not only in fossil bones and campsites but in the environment. Their primary tool was fire.

Erectus or sapiens, robust or gracile, one variable population or two (or more) distinct groups—regardless, Homo brought fire with him and picked up fire from the new lands he entered. His techniques for preserving fire were adequate to survive short sea voyages. It may have been, as in historic times, that fires were simply maintained on the craft in dishes of clay and sand. It may well have been the case that foraging parties were alerted to the new islands and eventually to the Sahul by bushfires. Even small fires with columns on the order of 1,000 meters can be seen from distances of up to 110 kilometers, which would readily render the Sahul coastline visible from Timor; more intense fires are common in heavier fuels. At night the light from fires carries brilliantly, a beacon. It is habitual for voyaging peoples to identify fire with humans, so it is possible that the smoke not only alerted early parties that land existed but promised human society as well. Once humans did arrive, their own ignitions made that promise a reality.¹⁰

The record of early hominids is, by and large, a record of fire. Fossil sites are universally associated with fire—with open hearths, with stony ovens, with charred bones, including cremations. Charcoal both preserves and makes possible dating by carbon-14 methods. It is obvious that the abrupt dispersal of humans around 40,000 years ago brought with it an unprecedented wave of burning that reinforced, if it did not catalyze, the internal revolution within the scleroforest that assured the dominance of Eucalyptus. Hearth fire contended with wildfire, broadcast fire with bushfire.

While fire practices varied in detail, they showed a remarkable uniformity in intent and effect. By the time Europeans arrived, the structure of the forest reflected tens of millennia of Aboriginal fire, a profound modifier of climate and a selector of biotic stocks. Virtually the entire landscape of Australia was itself, as Josephine Flood concludes, “an artefact created by Aborigines with their fire-sticks.” Even forested bush often resembed an open woodland or savanna, astonishingly like the oak woodlands and champion fields of England. Large grassy corridors were carved by fire for access to prime foraging and hunting sites.¹¹

Of course fire had its limitations. It could not roll back glaciers in the Tasmanian Alps, alter the patterns of the seasons, stay the rising seas, or, unaided, wipe out rainforest. Fire was a catalyst, a shaper, a multiplier of other effects and other practices. It was subtle, intimately tied to local sites and local practices. Without drought, fire could not invade rainforest, and anthropogenic burning could not indefinitely hold out against a wet climate intent on restoring rainforest over scleroforest. Fire could not promote thirsty flora in a dry climate. Fire interacted differently in various environments, affecting savanna in ways distinct from its effect on a Mediterranean terrain or a subalpine forest. Likewise, fire practices acted differently when used in concert with other human practices. Broadcast burning by one group would not be identical with burning by another group, or by similar groups at different times in their history.

Still, of all the implements in the toolkit of the Aborigine, fire was the most powerful because it went to the dynamic heart of Australian life. As Norman Tindale expressed it, “for at least fifty millennia during the Late Pleistocene, and subsequently, man has ranked with climate as the arbiter of change in Australia.” The Pleistocene revolution was a human revolution. Gently, insistently, violently, the Aborigine put Old Australia to the torch.¹²

FIRES OF REVOLUTION

The tempo of environmental reform intensified as the Pleistocene approached the last of its glacial epochs. Global changes revised, then rewrote over and again the physical geography of Australia. Temperature and precipitation regimes fluctuated, storm tracks migrated, seasonality became more pronounced—and less so. During glacial maxima conditions cooled, dried, and spread uniformly over season and place, sea level fell, and increased moisture made otherwise inhospitable sites in the interior habitable. During the interglacial periods, the climate was warmer, often wetter, and more seasonal and regional in distribution; sea level rose such that as much as 25 percent of the Sahul flooded. Rapid change became itself an inexpungable feature of Old Australia.

This climatic revolution paralleled a biotic revolution. The Pleistocene was a time of major extinctions and recolonizations. Extinction was a global phenomenon, but it affected different continents at somewhat different times and with different intensities. It was felt with special keenness in Australia. Among flora, scleroforest completed its accession over rainforest, and Eucalyptus claimed primacy among the scleromorphs. Among animals, megafauna were preferentially devastated. About a third of Australian megafauna—mostly giant marsupials like Sthenurus, a huge browser, and Thylacoleo, a lionlike carnivore—vanished between 50,000 and 15,000 years ago. The major extinctions, affecting the largest megafauna, occurred between 40,000 and 20,000 years ago. A slower rate of extinction, acting on somewhat smaller megafauna, continued for a few thousands years after than time. A third wave of extinction swept away two marsupial carnivores on the mainland—Thylacinus and Sarcophilus (the Tasmanian tiger and devil, respectively)—between 5,000 and 3,000 years ago. The magnitude of the Australian extinctions is comparable only to those in the Americas. Unlike the Americas, however, the species were not replaced, except by Homo and his sometime associate, the dingo.¹³

These coincidences—the advent of humans, the disappearance of a rich megafauna, the sudden ascendancy of the eucalypt—have argued for a causal linkage. Clearly massive extinctions have occurred in the geologic record without human assistance. Equally, the record of human colonization in prehistoric times is a register of selective biotic extinctions, and megafaunal extinctions, in particular, have tended to trail human migrations. In Pleistocene Africa, where humans and megafauna evolved in collaboration, few species were exterminated; in Eurasia, there were more; in Australia and the Americas, extinctions were apparently rapid and extensive. The historical record is especially telling with regard to islands, whether invaded by Siberians, Europeans, Madagascans, or Polynesians. Because of their isolation from human migration routes, both the Americas and Australia were effectively vast islands. Humans exploded into them almost without control.

Thus the Australian scene could be considered two ways: it was a climatic phenomenon, the last in a rhythm of Pleistocene extinctions from natural causes; or it was an anthropogenic artifact, among the first of the historic extinctions by marauding humans outfitted with spear and torch. The evidence is not unequivocal for either position. But it does appear that the extinctions occurred across all climate zones, that they preceded the onset of major aridity during the glacial maximum, and that the timing of migration and extinction is uncannily close.

What is apparent is that the Aborigine moved into an environment which was undergoing dramatic, perhaps irreversible change. These were circumstances to which Homo—an ambulatory weed, a species nurtured in the Pleistocene, a torch-carrying pyrophile—was well adapted. Of all creatures humans were prepared to survive in a disturbed environment, and humans became in turn a contributing disturbance. Whether the Aborigine hunted megafauna to extinction, or whether he burned away critical environments, or whether he favored some species who subsequently outcompeted rivals, or whether he only hastened an irrevocable decline driven by distant sunspots and Milankovitch wobbles in the Earth’s orbit, he was an important, an unprecedented presence. While his hunting mimicked other carnivores and his torch mimicked lightning fire, the rapidity, the purposes, and the scale of those actions made his abrupt arrival new and troubling. The Aborigine did not move passively into niches vacated by climatic extinction: some of those niches he created and others he actively sustained. As Josephine Flood argues, “the weight of circumstantial evidence favors human hunters as the decisive factor” in the revolution that was Pleistocene Australia.¹⁴

The interpretation of prehistoric fire history is anchored by two deep sediment cores. One comes from Lynch’s Crater on the eastern coast of Cape York Peninsula; the other, from Lake George in the tablelands of New South Wales. The Lynch’s Crater sequence dates back 140,000 years. During glacial maxima, scleroforest advanced somewhat on rainforest and charcoal lightly laced the preserved pollen. Then, around 40,000 years ago, the charcoal content abruptly increased tenfold and rainforest elements melted away before scleroforest. Thereafter, the charcoal content shrank to a lower, steadier level, then peaked after the last glacial maximum (c. 20,000 years ago). It disappeared when, after relentlessly wet conditions were reestablished, rainforest reclaimed the site around 8,000 years ago.¹⁵

The Lake George core dates back 350,000 years. Steppe grassland typified the glacial maxima, while Casuarina woodland characterized the interglacials. There is some charcoal preserved in the interglacial sediments, but around 130,000 years ago the oscillation ends; charcoal content quadruples; scleroforest, with a heavy eucalypt component, dominates the biota, resisting the climatic pressures to submerge the site under rainforest. A steady rhythm of burning persists unchanged into the Holocene. The overall quantity of preserved charcoal rises slightly. It is clear that ignition is now chronic, that the large amplitudes in the preserved charcoal contents signify droughts that allowed average fires to become extensive. It is suggested that the sudden magnification of burning prior to the last interglacial represents anthropogenic firing. If so, it is the earliest record of human presence in Australia—and an isolated artifact. More reasonable is the persistence of burning throughout the last glacial epoch, through wet and dry periods both, a regularity for which natural causes are an unlikely explanation.¹⁶

Other evidence testifies to remarkable changes around the whole continent at about 40,000 years ago. There are preserved hearths at Devil’s Lair in the southwest, at Lake Mungo in western New South Wales, and at Keilor in Victoria—all of which date from 38,000 to 32,000 years ago. Many hearth sites from around the continent date to around 20,000 years ago. Among indirect, geomorphic evidence there are charcoal-laden deposits (“red alluvium”) laid down by streams along the Darling Scarp that date to 37,000–28,000 years ago; charcoal lenses washed into the Koonalda Cave of the Nullarbor Plain, probably around 30,000–20,000 years ago; charcoal, silt, even charred wood deposited along the Darling and Lachlan drainages of the southeast around 21,000 years ago. In Tasmania even uplands were occupied and fired by 20,000 years ago and held in partial defiance of a returning interglacial climate. A major resurgence of burning and destabilized soils materializes around 7,000 ago; it is speculated that new lands, more heavily forested, were being opened to exploitation and burning. With the onset of roughly contemporary climate conditions around 6,000 years ago, that pattern of chronic firing, broken occasionally by drought-borne conflagrations, continues. Whatever else happened in Old Australia—whatever processes contributed to the extermination of its megafauna—anthropogenic fire was on the scene. If it did not contribute to the wave of extinction, it did reshape the environment in ways that made a megafaunal reconquest unlikely.

The subtlety and universality of anthropogenic fire makes it difficult to evaluate. There is no way to avoid its presence in Pleistocene Australia, yet there is no way to assess its full impact. Perhaps it is enough to say that anthropogenic fire was there, that it was ubiquitous, that it was capable of interacting with the rest of the Australian environment in ways that no other human implement could. It made the environment after the arrival of Homo fundamentally different from that which existed prior to Homo. Whether or not Aborigines actively destroyed megafauna or the megafaunal habitat through the use of fire, they certainly changed the conditions by which that environment could be repopulated. They changed the rules of the game. They made it impossible for the old species to regroup and reclaim their old niches. The Aboriginal firestick may well have been the smoking gun of Pleistocene extinctions.

It has often been observed that in Australia, unlike its closest analogue, America, no new megafauna replaced those that were lost. But this is not quite true: the versatile, omnivorous Homo seized those niches—not in one locale, but across the whole spectrum of Old Australia; not a single biota, but all of them. A variety of human cultures replaced the variety of Pleistocene creatures. Some forty species of megafauna were lost, but some seven hundred tribes of Aborigines, organized into perhaps two hundred linguistic groups, took their place. The specificity of their differences was fantastic; it is said that a tribe on one side of Sydney Harbor could not communicate with a tribe on the other. Once humans moved in, once anthropogenic fire was established, they were difficult to dislodge. In the new regime some creatures would thrive, and some would suffer. Their relationship to Homo—and to anthropogenic fire—would determine much of their relative standing. “The land the English settled was not as God made it,” archaeologist Sylvia Hallam concluded. “It was as the Aborigines made it.”¹⁷

Increasingly, as climate stabilized to roughly its present conditions around 6,000 years ago, human history drove natural history. The isolation of Australia discouraged other biotic invaders. Some new anthropogenic elements apparently intruded around 4,000 years ago, but otherwise Aboriginal existence was remarkably stable. Only other humans could dislodge what humans had fashioned. That did not occur until European colonization, which set in motion a biotic revolution that swept across Aboriginal Australia as the Pleistocene had Old Australia. Apart from outright extinctions, there was a profound restructuring of habitats such that indigenes, including the Aborigine, found it all but impossible to reoccupy old sites. Inevitably, fire was a vital catalyst. Once more it became for humans a point of entry, a tool of landscape modification, a weapon of interspecific (and intercultural) warfare. The history of this second invasion, as of the first, is one equally illuminated by fire and obscured by smoke.

“THIS THEIR PLACE OF DWELLING WAS ONLY A FIRE”

With uncanny mimicry, the genus Homo recapitulated the experience of the genus Eucalyptus. From an origin in other environments, humans adapted to the unique circumstances of Old Australia. Their total numbers were never extraordinary, but the specificity of their adaptations was astonishing. Societies of small endogamous clans favored genetic drift; their physical variability remained high. In effect, they became sclermorphs, discovering cultural equivalents to sclerophylly. With language the Aborigine possessed a means by which information and experience could be stored outside genetic codes. With nomadism, Aborigines could exploit the various resources made available at different places and at different times, overcoming the nutrient impoverishment or aridity of particular sites. With fire, the Aborigine could manipulate the dynamics of entire biotas.¹⁸

Like the eucalypts, Aborigines were uniquely indigenous to Australia. Genetic marker studies suggest that Aborigines have no close affinities with other human groups. The closest affinities—and they are based on traits that date back to very early origins—are to Southeast Asian and Melanesian peoples. Rather, the Australians developed in Australia. If they did not receive fresh genetic stock from outside sources, neither did they export their own. Until Europeans arrived, the isolation of Aboriginal Australia was almost total: nothing came in, and nothing left. Early colonization by the Aborigines and their subsequent isolation, however, meant that an entire continent bypassed the Neolithic revolution which had spread domesticated flora and fauna—agriculture—to the Old World. Unlike the Americas, no autonomous agricultural centers developed in Australia. None was necessary. Population remained light, and resources ample. The landscape could be “farmed” to an adequate degree by fire.

Within Aboriginal society fire was pervasive. It assured Aboriginal dominance over megafaunal Australia much as it confirmed eucalypt dominance over megafloral Australia. Fire and Aborigine were never far apart; on this the hottest and the driest of the vegetated continents, Aborigines habitually walked across the landscape armed with smoldering firesticks. Of fire’s role at the nuclear core of Aboriginal life, perhaps William Dampier put it best: “This their place of Dwelling was only a Fire, with a few Boughs before it, set up on that side the Winds was of.” Their shelter existed for the fire, not for themselves. The hearth, as Robert Hughes has observed, was for the nomadic Aborigine “of far greater significance than the home.” They carried their hearth—the society that it created and symbolized—with them.¹⁹

Yet the Aborigine had forged, as had the eucalypt before him, a Faustian bargain with fire. The dependence on fire was perhaps too total; the reliance on fire, for all the subtlety of its usage, too singular. Once committed to a fire-dependent society, anything that altered the status of fire or fuels would ripple catastrophically throughout the social and ecological system. Add new ignitions, remove old flora, alter the seasonal timing of fires—such changes would selectively reorder a biota. Tease apart the fuel structure and a whole ecosystem could unravel. While their reliance on the firestick made Aborigines a power in Old Australia, the society that lived by the firestick could also die by it. A landscape shaped by fire could be seized by more powerful fire.

When that moment occurred—when European fire arrived—it set into motion a biotic revolution that rivaled that of the Pleistocene. With breathtaking speed Europeans destabilized and restructured the fire regimes of Aboriginal Australia on a scale that had not been experienced for tens of millennia. Repeatedly, instinctively, Aborigines turned to fire to drive off the invaders. But the Europeans had even more assertive fire arms, and with domesticated biological allies they could attack the fuel structure of Australian fire regimes. A wave of extinction and of humanly dictated repopulations followed.

The pillars of smoke by day and of flames by night that likely beckoned the first humans across the waterways to Australia were a kind of siren song. They suggested that other humans were present, that humans could thrive in this environment because it could be manipulated by fire. Yet once in Australia there was apparently no means to depart and few alternatives to the widespread use of fire for survival. The rafts that brought early migrants to the Sahul could not be rebuilt with Australian materials. The route to Australia was a one-way journey, and once committed to a fire-intoxicated society, there were few opportunities to escape the firestick. The Aborigine, and Aboriginal Australia, became vulnerable to anything that distorted ignition, fuels, or the health of Aboriginal society. With palpable irony the smokes of Aboriginal Australia beckoned the Europeans, as the smokes of Old Australia had once called the Aborigines.²⁰