Plants and Human Conflict

Eran Pichersky

• Publisher: CRC Press
• Year: 2018
• Print ISBN: 9781138615311
• eBook ISBN: 9780429871924
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Biology
• Index: Biological Sciences

Perhaps the least appreciated dramatis personae in human history are plants. Humans, like all other animals, cannot produce their own food as plants do through photosynthesis, and must therefore acquire organic material for survival and growth by eating plants or by eating other animals that eat plants. Humans depend on plants not only as a food source, but also as building and clothing materials and as sources of medicines, psychoactive substances, spices, pigments, and more. With plants being such valuable resources, it is therefore not surprising that plants have been involved in practically all violent conflicts among different human societies. Ironically, plants have also been the source of materials to construct weapons or weapon parts.

Wars have always constituted a large part of human history, and the overall theme of this book is that to understand the history of violent human conflict, we need to understand what specific materials plants make that people find so useful and worth fighting over, and what roles such plant products have played in specific conflicts. To do so, Plants and Human Conflict begins with a chapter explaining the basic biological facts of the interdependence between plants and humans, and the subsequent seven chapters describe the physical and chemical properties of specific plant products demonstrating how the human need for these products has led to wars as well as contributed to the prosecution of wars. These chapters recount some well-known (and some lesser known) historical events in which plants have played a central role.

This book uniquely combines the modern scientific knowledge of plants with the human history of war, introducing readers to a new paradigm that will make them reconsider their understanding of human history, as well as to bring about a greater appreciation of plant biology.

1	Natural Resources as Causes of Violent Conflicts

Universal History

The term “history” generally refers to the field of study of past events that have involved humans. It is often restricted to the period after writing appeared and written records could be found to provide proof of the occurrence of specific events (although clearly many documents, past and present, are not truthful). Events that occurred before the invention of writing are sometimes classified as pre-history. Such ancient events can nevertheless be reconstructed from archeological evidence – human remains and the remains of human artifacts. But history is more than just uncovering past events. Serious students of history harbor the desire to understand why historical events unfolded in the way that they did. In scientific terms, they are interested in understanding the mechanisms involved in bringing about specific historical events, or, put simply, identifying causes of events.

Jared Diamond, in his book Guns, Germs, and Steel ¹ – which is basically a book about human history on Planet Earth in the last 13,000 years (nothing more, but nothing less either) – expressed his wish that human history become a scientific field of study, and not, as the common sentiment is today, something unapproachable by the scientific method. While some scientific procedures, such as the radioactive carbon [¹⁴C] dating technique, have now been widely accepted by historians, a term used here to include also archeologists, anthropologists, and several other related disciplines, there have been two main arguments against using the scientific method of gathering preliminary data, forming hypotheses about mechanisms, and testing their prediction in historical research. The first is that the subject is just too complex, so that every historical event is sui generis, the result of a unique set of a previous constellation of events that constitute the causes of the present event under study, and therefore no general methods can be applied to its study and no general conclusions can be drawn from such study. The second objection is that humans have free will, and therefore human history is not, indeed cannot be, deterministic. “Human choices made this history happen” is a typical comment.²

A specific variation of the complexity cum sui generis argument is the concept of “Great Men” in history. This concept posits that the personalities of charismatic leaders “cause” certain historical events – that is, the leaders’ personalities are the root cause of their behavior. The Great Men concept, which of course includes some great women as well, does not necessarily deny that human personalities are shaped by both their genes and their environment (although people often vehemently disagree on the proportional contribution of nature and nurture). However, while the lives of such Great Men are fertile grounds for biographers, attempts to understand exactly how biological, environmental, and cultural factors contributed to historical events by shaping the personalities of movers and shakers of human affairs, and every other person in society, are generally discouraged by historians, given the multiplicity of such factors and the enormous complexity of their interactions. In essence, historians, both those emphasizing the actions of singular people as well as those inclined to give more weight to the actions of the multitudes, limit their study to proximate causes of historical events – the direct action of people – and refrain from studying how each person at the time that his/her action under study occurred were themselves “caused”, or came into being, by previous events.

In short, whether attributing the cause of historical events to a few prominent human individuals or to popular movements, historians generally avoid studying causes of causes at too many steps removed. But by not pursuing root causes, historians are unable to draw general conclusions that would point to the operation of general “natural laws,” an outcome that historians often appear to approve of rather than lament. Thus, Thucydides’ conclusion³ that the “real,” or ultimate, cause of the Peloponnesian War was not the specific military incidents that preceded it, but instead “What made the war inevitable was the growth of the Athenian power and the fear which this caused in Sparta” is sometimes admired as a stroke of analytical genius but is as often derided as a presumptuous and unbecoming statement from a historian. Overall, the pervasive impression from present-day historical research is that history is not deterministic but is rather a stochastic, random process, and therefore that history cannot be predicted or even retroactively explained by any scientific methodology.

As Diamond points out, there are several well-established scientific disciplines that have a major historical component, such as astronomy, geology, and, of course, biology. What they all have in common is having as their subjects of study complex systems that keep changing their states because of previous actions. Oxygen molecules are the same now as they will be a million years from now and will behave the same way in response to other chemicals (depending on temperature, pressure, etc.) at both times, and therefore a simple equation can predict their behavior anytime. On the other hand, any living human being or another animal, a plant, or even a bacterium is a complex system that changes from one minute to another, because each constantly carries out biochemical reactions that change its chemical composition, internal structures, external shape, temperature, etc., and therefore will not behave the same way over time. A geological formation, such as a mountain, also changes over time (for example, by erosion), so its properties and “behavior” (e.g., how it retains heat or deflects wind) will also change over time.

Nevertheless, leaving human beings aside for the moment, all scientists treat such complex systems, both inanimate and living, as systems that can be studied by the application of the scientific method, so that their behavior in the past can be explained mechanistically and their future behavior can in principle be predicted, given sufficient knowledge. For all these systems, the concept of free will does not apply, and so any observed situation in these areas of study is thought of as the outcome of deterministic processes, the end result of a chain of causes and effects. Such chains of events are indeed often extremely complicated and therefore present conditions of a given system often defy – for now – complete mechanistic explanations, and futures states of such systems are often not amenable to accurate predictions. For example, atmospheric scientists still do not understand well why specific ice ages occurred when they did and how they played out, and they cannot predict the occurrence of the next ice age and its particular length and severity. Nor can geologists predict with any accuracy when and where earthquakes would occur or their strength. However, these shortcomings are attributed simply to lack of sufficient information as well as the inability to conceptually and technically analyze all the data already available. The argument that these issues are simply not amenable to the scientific method is not entertained by any serious scientist.

Although a general scientific definition of “complexity” does not yet exist, a strong argument can be made that living organisms constitute the most complex systems on earth in the sense that they are made up of the largest number of distinct parts – tens of thousands of unique genes, proteins, and metabolites – that interact with each other in multiple ways. Before Darwin published his book On the Origin of Species ⁴ in 1859, in which he promulgated the principle of biological evolution by natural selection, the descriptive study of living organisms – their components and their interactions with each other – was called “natural history.” This term is still sometimes used in this way, for example in the designation of natural history museums, while the study of the interactions among living organisms with each other and with the environment has evolved into the scientific discipline called ecology. Once the validity of the process of biological evolution was established, the term natural history came to describe, in addition to the aspects detailed in the original definition, also the study of the origins, evolution, and interrelationships of organisms. By that extended definition, human history is clearly a subfield of both natural history and ecology.

To be sure, for most people the motives for studying ecological systems that do not include people versus studying those that do are fundamentally different. Even ecologists don’t really want to write a book of a thousand pages describing how a geographical area with its myriad plants, animals, and microbes changed from year to year from say 500 bc to 500 ad. At best, they want to learn the principles that govern changes in such a system, so we can use this information to predict ecological changes today. But if this geographical area was the British Isles, and we were historians, we would likely try to record all “major” events, and some minor ones, that occurred there and involved humans during this time. We will note some changes to the system as a whole – for example, deforestation and the gradual elimination of many non-domesticated animal species – but only because humans were the causative agent (or so we imagine), and because such changes had in turn an effect on human affairs later on. “Random” natural events such as earthquakes, floods, or droughts will also be noted, but again only for their effects on humans, and would therefore be labeled as “natural disasters.” Basically, we will define our interest as “human history,” not ecology, and the interest of our readers would most likely be based simply on the need to relate to their own ancestors (if they are British) or to generally satisfy their curiosity about the past of our conspecifics, not to mention political needs such as establishing national standing and territorial claims. A “scientific” understanding of human history – abstracting the rules from specific cases – is not the major driving force in conducting historical research and writing it up, nor in reading historical research. But as I argue in this book, a scientific understanding of human history is not possible when the roles of all other components in the ecological system are minimized or completely ignored, and humans are considered as the sole causative agents of any action.

Besides the claimed insurmountability of the complexity problem, the second objection to making human history part of the scientific discipline of natural history, as mentioned earlier, is the idea of free will, which sometimes goes together with the blanket denial of any biological basis for human behavior. As noted above, humans as well as other living organisms are complex systems that are constantly changing. The cells that make up the human body grow and divide, and sometimes die, in response to both genetic and environmental cues. Information from the body itself and from outside the body is obtained by the nervous system and is stored in the brain, which undergoes physiological and chemical changes in response to these inputs. Given the complexity of the system, it is indeed difficult to predict what output a given input will elicit. Fair enough, but the concept of free will claims something fundamentally different. The concept of free will posits that output (human action) is independent of input – or, to put it another way, given a single defined input, multiple output choices are possible. If correct, it means that a person can somehow “choose” his action unconstrained by the condition of his brain, whose chemical and physiological state at the time the choice is made had been determined by the interactions of all past inputs, up to and including the said input, with the “hardware.” This concept is obviously at odds with the basic physical laws of nature, denying as it does that there is a physical cause, and only a physical cause, for each action, and has therefore been refuted by scientists beginning with the ancient Greeks. Nevertheless, the belief in free will is pervasive among laymen and even scientists.⁵

With the concept of free will disposed of, there is really no reason why in principle human history should not become a sub-discipline in both scientific fields of ecology and natural history. Perhaps this approach has been most closely adapted by those anthropologists who call themselves sociobiologists. Sociobiology, as defined by E.O. Wilson,⁶ is the study of social living organisms based on population genetics and evolutionary biology principles. Sociobiologists note that even learned ­behavior requires some hardware – some biological structures such as a brain – for it to be acquired and executed, so any genetic variation that leads to differences in that hardware could cause differences in behavior among individuals, and therefore could be subject to natural selection. The sociobiological approach does not specifically address how much “nature” versus “nurture” there is in any specific behavior, except to reject the extreme notion, still present in some cultural anthropology circles today, that all human behavior is learned and is transmitted among people absolutely independently of human biology, an untenable position since any human behavior, as noted above, has to reside in a biological system. The argument that cellular activities underpin behavior should not be turned into caricature statements such as “there is a gene for liking classical music” or “there is a gene for being a murderer.” Most behaviors are the results of the interplay between multiple genes as well as many environmental inputs.

Since the argument that “I am aware, or conscious, of making a decision, therefore I have free will to choose” is both scientifically untenable and inconsistent with experimental evidence, it follows that explanations of historical events that invoke “human choice” as ultimate causes cannot provide a complete, mechanistic explanation to human history. The analysis of the historical events described in this book will therefore be based strictly on materialistic arguments for cause and effect that are not dependent on human awareness. Such arguments, however, should not be confused with dialectic materialism, based on the writing of Marx and Engels (neither of them used the actual term, although Marx wrote about the “materialistic conception of history”). These two intellectuals knew little biology and in particular nothing about the biological basis of human behavior, and therefore, while correctly describing many “problematic” social conditions (problematic in the sense that at least some people consider these conditions to violate certain moral and social codes), often misidentified the ultimate causes of such conditions and proposed (or predicted) unrealistic courses of action to change these conditions. In keeping with the scientific treatment of history in this book, it is important to note that this book does not define anything as a “problem” and therefore does not propose any solutions. Instead, I attempt here to objectively present facts, identify patterns, and draw general conclusions about how the natural world operates under such circumstances. It must be emphatically stressed that such an approach should not tempt the reader to draw any conclusions concerning my own notions about the “justness” of the identified mode of operation of the natural world which humans are part of, and certainly not see it as a moral endorsement. Far from it – particularly, but not exclusively, when violence is involved. But morality is not an issue within the purview of science, and of this book.

From the ongoing discussion above it is fair to conclude that human behavior is a subject that falls within the scope of ecology, as does the behavior of any other living organism.⁷ In this book I will therefore definitely adopt the sociobiological framework. Contrary to the often-expressed sentiment that we should avoid turning to nature to explain human events, my argument is that there is no other way to fully explain human behavior (and culture generally) except by examining nature. As pointed out by Richard Dawkins in his influential book The Selfish Gene, ⁸ the evidence is clear that humans behave in principle like any other living organisms, driven by selfish genes and subjected to natural selection. However, by “examining nature” I do not mean only human nature, but the entire natural milieu that humans are embedded in. In fact, as my training is neither in human biology nor in history but in plant biology, the main focus of this book is to describe and illuminate specific aspects of plants that in my opinion have played very significant, indeed inordinate, roles in influencing the course of “human” history. Many of these aspects, of course, have already been studied, analyzed, and extensively written about, most notably the transition of human societies to farming, which depended largely on t...

Table of contents

• Cover
• Half-Title
• Title
• Copyright
• Dedication
• Contents
• Preface
• Acknowledgements
• Author
• Chapter 1 Natural Resources as Causes of Violent Conflicts
• Chapter 2 Fighting Grains
• Chapter 3 War and Slavery Capitalism – Sugarcane, Tobacco, and Cotton
• Chapter 4 Killer Spices
• Chapter 5 Caffeine, Opium, and Other Drugs for the Masses
• Chapter 6 Wood and Rubber
• Chapter 7 Modern Land Grabs –Hawaii, Palestine, and Latin America
• Chapter 8 Black Plant Power – Coal and Oil
• Appendix: Chemical Notations
• Scientific Glossary
• Index