.. The Raging Aftereffects ..
.. of Prehistoric Humans ..
According to generally-accepted scientific theory, the dinosaurs were annihilated in a series of asteroids that impacted the earth hundreds of thousands of years ago. These oversized reptiles were followed on their path to extinction by scores of megafauna, exotic by today’s standards, that roamed the forests and plains. Giant sloths, saber-toothed tigers, and mastodons all vanished, but unlike the dinosaur, their demise was not the overnight result of an apocalyptic deluge from the sky. Instead, their populations dwindled over a hundred thousand years, coinciding with the spread of humanity across the continents.
Fifty thousand years ago, humans wandered onto the Australian land mass, encountering hippopotamus-sized wombats, carnivorous kangaroos, marsupial panthers, twenty-five foot long lizards, and snakes three feet in diameter. Since that time, eighty-five percent of those species have died out. Though the humans hunted the massive animals with ease, they were relatively few, and could not possibly have caused such widespread loss. The extinctions were not the result of a natural climate change, such as an ice age, because they occurred in a temperate climate. Geologist Gifford Miller from the University of Colorado suspects that the humans altered the variety of flora, causing the extensive extinction through regular burning of the forest (Joyce). Certain plant life could not withstand the frequent fires ignited to facilitate hunting and the growth of edible plants, so many species were vastly depleted; the megafauna dependent upon these forests for survival died out in tandem.
Sediments at the floor of Wolf Creek Crater in Australia indicate to Miller that not only did aborigines Australians use fire to effect environmental change, but the fires instigated significant climate shift over the continent as well. These sediments relate the cycles of wet and dry seasons and the associated vegetation changes; the key to Miller’s theory lays in the wet/dry cycle alterations that occurred after the human arrival on the continent fifty thousand years ago. The aborigines set countless fires, and Miller speculates that the climate itself was transformed by the diminished water present in the biosphere. As the forests were wiped out, less moisture was recycled to the atmosphere through vegetal transpiration. The monsoon winds blew the now dryer air inland, where it failed to bring moisture to the interior continent. Consequently, the rainfall decreased, lending a transformative aridity to the inland region and changing it inexorably to desert (Grossman). There is an undeniable link between the burning activities of early humans and changes in the nature of their environment. Whether it manifested through forest depletion, megafauna extinction, or climate shift, the earliest and most basic human technology of fire has caused irreversible damage to the biosphere. Yet, this eon-old human tradition of destruction in the name of innovation continues to the present.
Deforming and deforesting, fire was harnessed by early man to alter the landscape, bend it to his will, and elevate himself above it. According to anthropologist Omer Stewart, it was the “first great force employed by man” (Williams 15), his initiation rite into the realm of scientific discovery and methodology that severed him from his ignorant past, distinguishing him from the apes. Man domesticated the wild forests, taming them with flames and heralding the first ecological transformation of the planet.
There is evidence that the early hominids expended great energy to preserve a piece of the wildfires that would ravage their habitat, realizing its productive potential. By generating wildfires of their own, the humans could make land more habitable and functional toward their survival. As land was burnt bare, useful animal and plant resources flourished. Frequent clearings advanced the growth of “favored plants such as grasses, forbs, tubers, wild fruits, wild rice, hazelnuts, sunflowers, cama, bracken, cassava, and blueberries” (Williams 16). The increase of desired vegetation would in turn attract desired fauna in greater numbers. Animals congregated in droves due to the burnings, and hunting thusly became more efficient. Both the varieties of plant and animal species were vastly improved by fires; vegetation yields grew between 300 and 700 percent, aligning with the matching faunal amplified population of 400 percent. Visibility as well as mobility were aided by the vast barren tracts. Potential threats were sighted from far away due to the open meadows and cleared underbrush; the increased visibility also yielded safer and more fruitful hunting. The multiple benefits of burning contributed to its manifesting as a desirable and frequent occurrence.
The cultivation of fire advanced early human practices that led to the emergence of modern civilization. The ability to attract greater densities of valuable animal resources probably directed the selective grouping of the herds, a process that was the precursor to the “herding-husbanding-domestication of animal populations” (Williams 18). This could have ultimately yielded such concepts prevalent throughout human culture as possession and territoriality. Fire was also used for cooking meat and boiling water, a concept that naturally lent itself to the emergence of ceramics and metallurgy. Fire became enmeshed in the human psyche as a profound religious force, a requisite aspect of creation and damnation mythology. Additionally, it provided warmth and warded away darkness, allowing for population and territorial expansion. Fire was the focal point of early communitarian experience, and as the use of fire flourished, so did family life and the structured, settled living necessary to maintain the fire supply. Gathering at the fire circle, prehistoric humans began to discuss their experience and communicate group knowledge and perceptions. Finally, fire established a precedent that demonstrated to humans that they could exert control over other nonhuman resources, such as animals, and in due course they become the sole species on earth to achieve dominance over their environment (Williams 19).
According to the most widely-accepted theory of evolution, technically-advanced humans emerged only 40,000 years ago in a “big bang” of development with the advent of grammatical speech, followed by symbolic thought. The scientists who promote this theory regard our forebears Homo erectis as big-brained, but primitive. However, various findings over the past thirty years are beginning to turn this theory on its head. At Koobi Fora in Kenya, archaeologists found the stone tools and remains of Homo erectis as well as 1.6 million year old “lenses” of orange earth. This tinted dust is most probably the aftermath of small, contained fires left by early hominids. Jack Harris of Rutgers University believes that these fires were indispensable in keeping large carnivores as well as colder climes at bay in the night of Africa’s Great Rift Valley (McCrone 30-31). Also, thermal alterations on remnants of basalt and quartz tools further bolster the evidence of Homo erectis’ harnessing of fire (McCrone 33). If these claims can be verified, then the use of fire by humans throughout time to overcome environmental forces is a fundamental and defining aspect of human nature.
By taming fire, humans have forged a dynamic relationship with their environment. Fire technology has allowed our species and its predecessors to transcend the natural state, manipulating it to our advantage. Homo erectis’ use of fire illustrates that human evolution is a gradual process; modern humans did not emerge overnight in a “big bang” of development, but rather slowly adapted from their primitive origins. Fire, the very first application of science, has played a leading role in human evolution, for it has accompanied us in our progression for almost two million years. Controlling this powerfully destructive force introduced a new dimension to the human experience. We stopped seeing ourselves as creatures of our environment, but rather as its masters. As we further separated ourselves from natural instinct, we built artificial environments to replace our wild origins. The constructed reality of our environment soon led to the constitution of artificial thought, or abstract concepts, the harbingers of speech and the institutions of society. From the beginning, technology was used to benefit humankind. Simply wielding these instruments, however, effected profound change in our environment, whether this change manifested in deforestation, extinction of megafauna, and climate alteration, or today’s global warming and acid rain. We propose new technologies to reverse these harmful ecological effects, and thusly, the evolution of human endeavor perseveres.
Grossman, Daniel. “Aboriginal Climate Change.” National Public Radio. 17 Mar. 2002.
Joyce, Christopher. “Megafauna Extinction.” National Public Radio. 8 Jan. 1999.
McCrone, John. “Fired Up.” New Scientist. 20 May 2000, Vol. 166, Issue 2239, pp. 30-34.
Williams, Michael. "Deforesting the Earth: From Prehistory to Global Crisis" (Univ. of Chicago Press, 2003) pp. 3-36.
Return to ENVS2 homepage
Send message to Swarthmore College Environmental Studies
last updated 2/05/06webmaster