Human Ecology Forum The Major Transitions in the History of Human Transformation of the Biosphere András Takács-Sánta Hungarian Academy of Sciences and Eötvös University Research Group for Evolutionary Genetics and Molecular Genetics Eötvös Loránd University of Sciences Pázmány Péter sétány 1/C, 1117 Budapest HUNGARY1 Abstract or even more, that is the transitions were not always “revolu- tionary” changes. In this article the six most important tran- The aim of this interdisciplinary review is to provide a sitions are examined. In chronological order these are: new framework for the research in the history of human • The use of fire — from at least 250,000 years ago. transformation of the biosphere. It focuses on the major tran- • Language — from at least 40,000 years ago. sitions, which resulted in a considerable increase in our • Agriculture — from at least 10,500 years ago. species’ impact on the biosphere (in relation to the state • Civilization (states) — from about 5,500 years ago. before the transition). Six such transitions are identified, in • European conquests — from the 15th century A.D. chronological order these are: 1) the use of fire, 2) language, • The technological-scientific (r)evolution and the dom- 3) agriculture, 4) civilization (states), 5) European conquests inance of fossil fuels as primary energy sources — and 6) the technological-scientific (r)evolution and the dom- from about the second half of the 18th century A.D. inance of fossil fuels as primary energy sources. Such an Ranking the transitions according to their importance inquiry of our biosphere transforming activities may be of would be a hard task and it is not the aim of this article. great importance in establishing ecologically sustainable Nevertheless, this does not mean that each of the transitions societies. was followed by an equal increase — either in absolute terms or in relation to the situation before the transition — in our Keywords: human transformation of the biosphere, transformation of the biosphere.3 human evolution, environmental history, global change, sus- tainability The Model In discussing the major transitions the model of Holdren Introduction and Ehrlich (1974) is used. According to this model, the extent of human transformation of the biosphere depends on Every living organism transforms the biosphere — the three factors directly (and is in direct proportion to all of part of the Earth in which life engaged in active metabolism them): 1) population size, 2) per capita economic output, and naturally exists (Hutchinson 1970) — to a certain extent 3) environmental impact (i.e., transformation of the bios- (Odling-Smee, Laland and Feldman 1996), but Homo sapiens phere) per unit economic output. (Obviously, the three fac- is by far the most efficient species in this respect.2 Our bios- tors are not independent and behind these direct causes there phere transforming activities have become so extended that can be found an intricate web of indirect ones.) It is worth even our own well-being — as well as the existence of many dividing the third factor into further elements. The environ- other species — is already threatened. This review outlines mental impact per unit economic output depends on at least the history of our species’ becoming so different from other three factors: 1) how “environmentally friendly” are the tech- species in regard to transformation of the biosphere. In other nologies used, 2) what is the structure of the economy words, it describes the history of the increase in the extent (whether it is composed of economic activities causing (and pace) of this transformation. This increase has not been greater or lesser environmental impact), and 3) what is the linear. Transitions can be identified, which resulted in a con- spatial pattern of the economy (to what extent the certain siderable increase in our impact on the biosphere, not in phases of the economic process are separated in space — in absolute terms, but in relation to the situation before the tran- most cases environmental impact increases with greater sition. In some cases these increases took several millennia separation). Human Ecology Review, Vol. 11, No. 1, 2004 51 Human Ecology Forum Model and Framework: Problems and Virtues tant environmental changes. Furthermore, it should be con- The Holdren-Ehrlich model is highly suitable for use sidered not more than a brief account, aiming mainly at the and provides an appropriate guideline for the discussion of stimulation of discourse and further research by providing a this article. Nevertheless, it has some drawbacks as well. new framework. Here, one of these is worth emphasizing: the model fails to describe the dynamics of changes, in other words, it does not First Transition: The Use of Fire reflect the pace of environmental transformation. In regard to the adaptability of nature and society, however, not only the Our species, Homo sapiens,originated from Homo erec- absolute extent of a certain environmental transformation, but tus about 600,000 years ago (Clark et al. 1994). The first also the length of its time interval is important (see Dietz and undisputed direct evidences of human use of fire (a techno- Rosa 1994 for more). (The chances of adaptation decrease logical change4) are related to Homo sapiens. These are about with increasing pace of transformation.) 250,000 years old and derive from Europe and the Near East The above-mentioned events can be considered as tran- (Pennisi 1999). Archaeological evidence, however, indicates sitions, because they all increased considerably at least one of that humans were able to survive in northern Eurasian habi- the three factors in the model. However, since — at least in tats (above about 50˚ N latitude) by about 500,000 years ago, this model — the extent of human transformation of the bios- which would have been rather difficult without fire (Stiner phere cannot really be determined numerically, the identifi- 2002).5 cation of the major transitions is inevitably subjective. The domestication of fire was an important prerequisite Therefore, theoretically it is possible to identify less or more for the use of biomass energy (and much later for that of fos- transitions than those discussed in this article. In spite of this sil fuels). Biomass was our first extrasomatic energy source limitation, identifying the six major transitions discussed and it has remained important ever since. (The amount of here seems to be plausible according to our current state of extrasomatic energy available to us correlates positively with knowledge. the extent of transformation of the biosphere.) A complex approach is used to identify and discuss the The use of fire has increased transformation of the bios- major transitions. I rely on both the natural and social sci- phere for the following reasons (Bellomo 1994): ences as well as philosophy, without giving distinguished role • Fire made possible the clearing of vegetation (even in to either of these. I believe that natural forces, social struc- large areas).6 Later, it became useful in hunting large tures and ideas (or values held by people) have played almost animals — by the help of fire they could have been equally important roles in shaping our biosphere transform- driven toward the place of slaughtering. ing activities. Likewise, these activities have shaped the • Fire could have been important in keeping off carni- social structures, and ways of thinking as well. Thus, this vores dangerous to humans. It is likely that this was review leans on the results of several disciplines, hopefully our first efficient means against them. This may have providing new insights not visible from narrower perspec- resulted in the growth of human populations. tives. • The use of fire made easier the peopling of colder To my knowledge, the history of human transformation areas and made possible the inhabitation of very cold of the biosphere has not yet been investigated focusing on places. The expansion of the geographical area of such major transitions. Although some other works are sim- humans is usually accompanied by the growth of the ilar to this one in some respects, there are considerable dif- world population. ferences. It is because these other papers determine the • Cooking has been an important utilization of fire. By major transitions from a single aspect only (e.g., Bennett and cooking, potential foods unavailable before have Dahlberg 1990; Simmons 1996), concentrate on shorter time become palatable and also the digestibility of some intervals (e.g., Crosby 1986; McNeill 2000; Meyer 1996; kinds of food was improved (Wrangham et al. 1999). Turner et al. 1990), discuss considerably fewer major transi- Energy input increased in this way could have signifi- tions (Ponting 1991), or use a different framework (e.g., cantly contributed to the increase in the relative size of Simmons 1993). the brain (its size in relation to body size), an organ Although this article examines the history of human demanding a lot of energy (Aiello 1998). (This contri- transformation of the biosphere from our species’ origins to bution certainly does not mean a simple cause-effect the present, it is inevitably fragmentary because it concen- relation.) Relative brain size correlates positively with trates mostly on the periods of the major transitions, puts mental capacities and any increase in the latter results more emphasis on the consequences of the transitions than on in extended transformation of the biosphere (mainly their causes, and