Guns, Germs and Steel, by Jared Diamond

A non-fiction book examining the history of human civilisation might seem an odd work to review in an SFF blog but bear with me, there is some relevance to it. Guns, Germs and Steel sets out to answer some fundamental questions about civilisation, which is defined as the introduction of farming, thereby producing enough food to support large, settled communities with social structures, rulers, priests and armies. In particular, why did civilisation develop in some parts of the world but not others?

The author covers a lot of ground while trying to answer that question, in the process conveying an excellent summary of what is known (and not known) about the early history of civilisation. Simplistic theories I recall from my youth to explain why people of European origin have dominated the history of the past few centuries, concerning such matters as an invigorating climate or the tenets of Protestant Christianity, are ruthlessly dismissed with evidence-based logical reasoning. Instead, Diamond argues that a range of environmental factors made the varied history of different parts of our planet almost inevitable.

The most fundamental factors concern how easy it was to begin farming, and this largely depended on three factors: the suitability for domestication and improvement of the wild crops available in each area; the suitability for taming and domestication of the large wild herbivores (or in a few cases omnivores) in each area; and the combination of climate and terrain. For all three factors, the Fertile Crescent of the Middle East (centred on what is now Iraq) had substantial advantages. The ancestors of most of what became crops of world importance lived wild in the area. So did the ancestors of nearly all of the large animals which have proved suitable for domestication (the "big five" being sheep, goats, cattle, pigs and horses; others, such as camels, are of only regional importance). The climate was good for cultivation, with a long growing season, and the varied terrain meant that not all crops ripened at once; those higher up in the hills and mountains would ripen after those in the valleys and plains, ensuring a steady availability of food rather than a sudden glut. These advantages enabled the Fertile Crescent to become the cradle of the civilisation which developed in the surrounding areas, including all of Europe.

Although centres of agriculture developed independently in several other parts of the world, most of them were much less well endowed with plants suitable for cultivation, so it was difficult for them to gain the same food value out of a given amount of land or physical effort. Most also lacked large animals suitable for domestication, which not only denied them a source of convenient protein but also meant that they had no power source to do the heavy work of ploughing and transport or to act as war mounts. That was a massive disadvantage, and accounts for the rapid adoption of such animals wherever they were introduced (e.g. the use of horses by the natives of North America).

Another advantage of the Fertile Crescent is that lands with similar climates and growing seasons (including Europe and North Africa) extended to the east and west, making it easy for the new farming practices to spread. In the Americas, with a north-south rather than east-west axis, it was much harder for such practices to spread from temperate lands in North America to those in the South (and vice versa), because the tropical Mesoamerica blocked the way - and crops and animals adapted to temperate climes rarely succeeding in making that journey until long-distance transport became feasible.

Once the process got underway, other factors came into play to ensure that the early civilisations were able to spread and dominate their neighbours. The higher population densities and more intensive food production of these civilisations allowed them to develop ruling classes and armies against which more primitive, dispersed and decentralised cultures had no resistance. Furthermore, the high densities, combined with the close proximity of humans and animals, provided fertile ground for the development of new diseases. People in such civilisations gradually built up immunity to such diseases, but when they arrived in new lands (most especially in the sixteenth century when Europeans began to arrive in the Americas in some numbers) the native peoples had no such resistance and the death rate from the resulting epidemics could be as high as ninety percent.

With such huge advantages giving it a flying start, one might wonder why the Fertile Crescent is relatively poor today. The answer, the author points out, is that they used their land too intensively. With what used to be extensive woodland cleared for farming, and goats eating almost anything that grew there, the soil became impoverished. Long-term changes in rainfall patterns also had a part to play in worsening the conditions for agriculture in various parts of the world.

Once civilisations had made a start, other factors determined which were able to develop technology and which were not. Once again, the location was all important; the ready availability of metal ores suitable for easy processing for copper, tin and later iron, was vital to developing modern industries.

The evidence amassed by the author indicates that in almost (although not entirely) every respect, it was the relative advantages in natural resources - climate, terrain, cultivable plants, domesticable large animals, and minerals - which determined which cultures have flourished and which have not. Some mysteries remain, however; such as why an early civilisation as advanced and extensive as the Incas of South America never developed writing or invented the wheel.

One other interesting point is raised, and that is the importance of a high population density over a large area in sustaining early technological advances. Many early innovations were probably introduced many times over, only to be lost as the small isolated bands of hunter-gatherers which developed them died out. It was important for innovations to be spread widely over a large population for them to become well established. Furthermore, cultures could lose their technologies if they became isolated in sufficiently small groups. A poignant example is given of the natives of Tasmania, a large island which used to be joined to mainland Australia. At that time, the Australian aborigines - including those in Tasmania - were using sophisticated stone tools, large-scale fish traps, boomerangs and other technologies. It is estimated that about 4,000 people were living in Tasmania at the time of the separation some 10,000 years ago, but by the time the first Europeans arrived they had lost all of their advanced technologies and were surviving only at the most primitive level of existence. Even worse, on some smaller islands similarly separated from mainland Australia, estimated populations of 200-400 died out completely. It seems that there are certain minimum levels of population to sustain any kind of existence, and the more advanced is the civilisation, the larger the population needs to be.

Some technologies have been lost even by advanced civilisations just a few centuries ago. Early in the fifteenth century China possessed large fleets of huge, advanced sailing ships and several major expeditions (involving up to 28,000 men) were launched, reaching as far as Africa. China looked set to dominate the world in the way that Europe began to at the end of that century - but then, as a result of political infighting, the ruling group which was closely associated with the expeditions lost power and their successors promptly scrapped the fleets together with the capability to build and use them. I could add more recent examples, admittedly of much less significance: in the last few decades the West has developed and abandoned both the capacity to land men on the Moon and the ability for passenger planes to speed across the Atlantic at twice the speed of sound. Nuclear power is also being abandoned by several countries. Technological capabilities do not always advance, even for us.

So what is the relevance of all this to SFF? I think that there are some clear lessons here for authors who are engaged in world-building, especially of primitive civilisations, and who want to make their worlds as realistic as possible. Also for those concerned with writing stories of survival after disasters, either on this planet or others, in which a rapid slide down to basic subsistence level of existence seems likely. There is far more in the book than I can go into here, but I recommend it to anyone interested in why and how civilisations develop - and manage to survive.