THE ORIGIN OF CIVILISATION

Homo sapiens, our species, has probably existed for at least 200,000 years, and possibly more than 300,000 years. We know this because, although dating methods are less precise for such old materials, the remains of what appear to be archaic forms of Homo sapiens, between 200,000 and 300,000 years old, have been discovered at several sites within Africa. It’s difficult to know precisely how old our genetic lineage is because such finds are extremely rare. But studies of DNA, and the rate at which it can evolve, suggest these early dates are entirely reasonable.

In which case, why did civilisation begin only relatively recently, at the start of the Holocene period, or shortly before, around 11,000 years ago? This issue, the origin of civilisation, is considered one of the most important and difficult in anthropology and archaeology.

It is generally thought that agriculture heralded the origin of civilisation. This is why there is so much interest in the emergence of domesticated strains of crops and animals within the Fertile Crescent after the end of the Younger Dryas period. There appears to have been a revolution in lifestyles that quickly took hold across this region, a process sometimes called the ‘Neolithic revolution’ that led to larger and more sophisticated communities, and ultimately to our modern world.

But Göbekli Tepe has muddied the water here by indicating that a large community of specialists might have existed thousands of years before farming became established, or at least before domesticated strains of plant and animal are recorded. This means agriculture might have developed in response to the emergence of larger-scale communal living, rather than the other way around. Perhaps agriculture was simply a means to an end, a way to feed more mouths. As the saying goes, where there is a will, there is a way, and perhaps the will to live together came first. This is one reason why Göbekli Tepe is so important to anthropologists and archaeologists, because it helps to deduce the motivations, the key drivers, for events. Even so, one still has to explain why it took so long for larger communities with specialists to develop, considering that we had existed as a species for at least 200,000 years already.

Environmental conditions are often cited to answer this question. During the last ice, which began over 100,000 years ago, it is thought that resources, like food and shelter, were harder to find, resulting in low populations that limited the potential for civilisation to begin. But while this might be true at higher latitudes, this argument does not hold so readily for regions near the equator, like Africa, India and south-east Asia. Even though, globally, the world was colder during the last ice age, and therefore more arid because more water was locked within polar and continental ice sheets, towards the equator there would have been regions with temperate climates and relatively comfortable conditions sufficient for civilisation to take hold. So, the occurrence of several ice ages over the last 300,000 years doesn’t really explain why civilisation began only relatively recently.

Sometimes, it is claimed that extreme climate fluctuations, such as the Daansgard-Oeschger oscillations that occurred over the last 40,000 years of the last ice age, tend to disrupt and prevent the formation of larger communities. While this is entirely likely, it does not explain why civilisation did not begin during the last glacial maximum, around 27,000 to 17,000 years ago, in the southern hemisphere, or during the last interglacial period, over 100,000 years ago within Africa. Global climate during either of these epochs was relatively stable for at least 10,000 years. So, why didn’t civilisation begin during either of these stable climate periods?

This has led some to suggest that the Younger Dryas period, which directly preceded the Neolithic revolution, is in some way special, and led to a change in ‘cognition’, or a change in people’s thinking and motivations. If this is correct, what was the change in cognition that occurred, and was the Younger Dryas event responsible for it? If it was, then why did earlier catastrophes, like the one recorded by the Lascaux Shaft Scene, not have a similar effect? Again, it seems this idea, that the Younger Dryas event led to a change in cognition, by itself, does not solve this problem. There are probably other factors in play.

Göbekli Tepe is the earliest structure in the world yet known that hints at the existence of a sophisticated culture, or civilisation. It is reasonable to think that civilisation existed there before anywhere else in the world, especially considering it lies at the heart of the Fertile Crescent where agriculture appeared for the first time while Göbekli Tepe was inhabited. But, although we have very likely solved core aspects of the symbolism of Göbekli Tepe, we do not yet have an answer to these important questions about the origin of civilisation. To try and find them, it will help to look further afield at the context of Göbekli Tepe in the Fertile Crescent. To get a handle on this issue, it is useful to ask a more direct question – who built Göbekli Tepe?

Natufian Culture

The original construction of Göbekli Tepe has been credited to a New Stone Age (Neolithic) culture, after the end of the Younger Dryas period, by the site’s archaeologists because of the earliest radiocarbon date of some mortar from one of its enclosures, circa 9,530 BC. However, the date inscribed onto Pillar, the Vulture Stone, is at least one millennium earlier than this, and corresponds closely to a cultural transition, from Early to Late Natufian in the Fertile Crescent, near the onset of the Younger Dryas period. Therefore, the original builders of Göbekli Tepe are likely Natufian, or contemporaneous with the Natufian, who lived in the Levant near the east coast of the Mediterranean at this time. Is this credible? How much do we know about these people? Were they sufficiently sophisticated to have built a magnificent structure like Göbekli Tepe?

Much research distinguishes between ‘Early’ and ‘Late’ Natufian periods. The Early period, apparently occurring prior to the Younger Dryas mini ice age (before 10,900 BC), is thought by many to be more settled than the Late period, occurring within the Younger Dryas period (around 10,900 to 9,600 BC), for which evidence of a return to a semi-nomadic lifestyle is often suggested, although this trend is not ubiquitous178 and is not reflected at Göbekli Tepe. Research that uses the most accurate and modern radiocarbon dating methods supports this separation of cultures, and suggests it was caused by the dramatic change in climate at the onset of the Younger Dryas period. Obviously, we can now point towards the Younger Dryas event itself as the cause of this change in climate and transition in culture.

The Natufian are the most advanced pre-Neolithic culture yet discovered in the Levant, so if anyone in the region could have built Göbekli Tepe, they are the most likely. But we cannot be sure of this – we cannot simply make this assumption. We should search for evidence that clearly shows who built Göbekli Tepe. Frustratingly, the actual settlement where the people who built Göbekli Tepe presumably lived has not yet been found. According to the site’s archaeologists, Göbekli Tepe is not a residence itself, as they have not found the usual evidence of habitation, such as the everyday implements used for cooking. This makes identification of Göbekli Tepe’s builders difficult.

Stone tools found in the fill that covered the site correspond most closely to the Neolithic period after the Natufian phase, suggesting its builders were Neolithic, and not Natufian. But this is only to be expected and is probably a red herring. The fill used to cover the site will naturally consist mainly of materials and waste from later phases of occupation just before the site was abandoned. So, this evidence doesn’t help us determine who built the site originally, several thousand years earlier.

To help us unravel this mystery we should search for similarities between Göbekli Tepe and Natufian archaeological sites, or other sites. If the Natufian built Göbekli Tepe originally, there should be evidence of their capability at Natufian archaeological sites prior to the construction of Göbekli Tepe. As the precise date of its construction is unknown, both Early and Late Natufian settlements should be considered. Indicators in the form of i) permanent settlements, ii) agriculture required to feed a large workforce, iii) social organisation required to coordinate the whole endeavour, iv) advanced masonry required to cut, erect and carve the pillars, and v) symbolism and artistry found at Göbekli Tepe should be evident. There are only a handful of Natufian archaeological sites currently known. Let’s see what they reveal.

The issue of sedentism is relatively easy to answer, as one of the defining characteristics of Natufian culture, especially Early Natufian, is permanent settlements consisting of boulder-lined huts dug into the ground, forming small villages of a few hundred people. The permanence of these villages is indicated by the energy expended to create the dwellings, for example the movement of large boulders and the levelling of ground, as well as the existence of storage pits, wall plaster, and the remains of small scavenging animals, such as mice and other rodents.

There is general agreement among Paleo-botanists that the earliest evidence anywhere in the world for domesticated varieties of any plant or animal occur after the Natufian period within early phases of the Neolithic in the Fertile Crescent. However, the story concerning cultivation of plants, as a precursor to proper domestication, is much more contentious, and there is little agreement among researchers as to whether the ‘roots’ of plant cultivation and wild animal management can be traced to a core area near Göbekli Tepe, or whether these developments are much more dispersed across the Fertile Crescent and perhaps beyond. Neither is there much agreement on the timing of these earliest experiments in farming. Nevertheless, Natufian people are normally viewed as hunter-gatherers, or more correctly, hunter-collectors, as they appear to have stored grain at their settlements. Part of the problem, of course, with establishing timelines is the interpretation of radiocarbon dating methods. And the Younger Dryas event will no doubt have been very destructive, making any archaeological evidence harder to interpret. But, it is probably true that permanent settlements and initial experiments with cultivation and animal-keeping to supplement a largely hunting and gathering lifestyle went hand in hand for Early Natufians.

The largest known Natufian settlements likely consisted of up to a few hundred villagers, indicating a limited form of social organisation or hierarchy. Was this sufficient to construct a grand project like Göbekli Tepe? No other older archaeological site yet found compares even remotely with the scale and vision of Göbekli Tepe, and it is only several millennia later that Jericho in Palestine, hundreds of kilometres to the south, comes close to it. This is one of its most astonishing aspects; it is completely anomalous in this respect. Perhaps several hundred Natufian villagers might have been able to construct it given sufficient motivation – the kind of motivation that might be provided by the extreme circumstances of the Younger Dryas event.

Early Natufian dwellings consisting of megalithic circles dug into the ground, with a topping of wood and brush, hardly equate to the level of sophisticated stone-working demonstrated at Göbekli Tepe, but their architecture is not so different. Probably the most advanced masonry skills uncovered at any Natufian site are found at Tell Qaramel, over 150 kilometres south-east of Göbekli Tepe, with the construction of a stone tower supported by megalithic foundations. The tower was rebuilt on the same spot several times over the course of many hundreds of years, with some foundation stones nearly one metre thick. Although these towers are confidently dated to the Late Natufian period and afterwards, there appears to have been an even earlier stone tower built on the same spot in the Early Natufian period, although it is difficult to be sure because little remains from this period.

Regarding the large-scale artistry evident at Göbekli Tepe, there are no clear indications of these skills anywhere within Natufian settlements. Instead, typical artistic finds in Early Natufian settlements appear to be limited to small stone, clay and bone sculptures, with shell and stone jewellery. But, as we have seen, grand artistic displays are found at many ancient cave sites in Western Europe, such as Chauvet, which are tens of thousands of years older than Göbekli Tepe. Considering this expertise existed at such an early time within Europe, soon after people had migrated over long distances westward from Asia, it makes sense to presume this expertise existed across the whole of Eurasia. It was likely ubiquitous, although perhaps it was rarely expressed in such a durable form as stone.

Indeed, some of the symbolism found at Göbekli Tepe is also found at Late Natufian sites. A prominent example is Hilazon Tachtit cave, near Galilee, where an elderly woman is found buried together with the remains of a boar leg, eagle wing tip, over fifty tortoise shells, stone martens and an aurochs tail184. This is interpreted by the site’s archaeologists as the burial site of an important person, probably a shaman. And stone plaquettes, are not uncommon among Natufian sites – they are found at Tell Qaramel, for example. But the age of these plaquettes is unclear – they might be Neolithic and not Natufian. Nevertheless, a potential connection with Göbekli Tepe, in terms of cultic practices involving similar animal varieties and symbolism, is easy to make.

Very interestingly, cupules, which are small hemispherical holes carved into a rock surface about the size of a tennis ball, are found in abundance in stone floors near Natufian burial sites. The same kinds of cupules are found at Göbekli Tepe, both in the nearby bedrock and on the tops of many pillars. They are also found at many other ancient sites across Europe and the Near East, indicating use of these marks spans an extraordinarily wide timespan and geography. In fact, they are found across the whole world at megalithic sites, including Easter Island. It is thought by some that these cupules, and megalithic circles and constructions in general, are associated with astronomical observations. Probably, they can be linked to the ancient Laurasian system of astro-mythology defined by Witzel.

What should we conclude from this brief survey of Natufian archaeological sites? Is it clear that Göbekli Tepe was built by a Natufian community? Not really. There appears to be quite a large cultural gap between known Natufian sites and Göbekli Tepe. So much depends on whether a phase of Natufian cultural development is discovered that forms a bridge between currently known sites and Göbekli Tepe. This phase of development might, of course, be found eventually at Göbekli Tepe itself. The main problem is that the level of communal organisation required to build Göbekli Tepe does not seem to be present at any known Natufian site.

This is not to say that a Natufian community could not have built Göbekli Tepe alone. The extreme circumstances of the Younger Dryas event might be sufficient to explain the apparent cultural discontinuity between known Natufian sites and Göbekli Tepe. But as things stand, it is not obvious they do.

Therefore, until more archaeological evidence is found, either at Göbekli Tepe or elsewhere, that fills in the details of this gap, this remains an open problem. But logically, we have the following three scenarios.

1.Göbekli Tepe was constructed initially by non-Natufian refugees settling in a new land, perhaps from Western Europe where this level of artistry and knowledge is evident, in line with Mary Settegast’s Atlantean hypothesis. The problem with this idea is that evidence of a more advanced civilisation than the Natufian just before the Younger Dryas event is lacking, so one would have to also argue that their homeland was destroyed by the cataclysm or, due to sea level rise over the last 13,000 years, possibly resides under 100 metres of water. This is Graham Hancock’s view.

2.Göbekli Tepe was constructed by a Natufian community relocating from elsewhere in the Levant more advanced than any currently known. Again, the problem with this view is that there is no evidence of a more advanced Natufian settlement in the Levant, so again, one would have to argue that it was destroyed by the cataclysm or, perhaps due to sea level rise, has not yet been found.

3.Göbekli Tepe was constructed by a Natufian community, or similar community in Anatolia. The earlier phase of cultural development, which spans the cultural gap between the grandest phases of Göbekli Tepe’s construction and known Natufian sites, will be found through further excavations at Göbekli Tepe or nearby sites, like Tell Qaramel.

If either case 1 or 2 is correct, then it implies that civilisation had already begun elsewhere and therefore the Younger Dryas event played only a minor role in its development. In which case, neither a change to a warmer climate nor a change in human cognition are obvious drivers for the origin of civilisation. Normally, the possibility that the green shoots of civilisation could have appeared before our current Holocene period, the last 11,000 years or so, is ruled out by scholars on the basis that agriculture is a necessary prerequisite. But Göbekli Tepe shows this view is not quite correct, and that initial attempts to form larger communities of specialists can occur without recognisable agriculture. In other words, we are no longer constrained in our search for the origin of civilisation by the appearance of domesticated plant and animal varieties. This is the important lesson Göbekli Tepe demonstrates. In which case, how can we know if civilisation began at other sites in earlier times? What evidence should we seek instead? We’ll come to an answer for this question in the next section.

But, on the other hand, if case 3 is correct, which I consider most likely as there is no clear evidence to support case 1 or 2, then we should consider whether the Younger Dryas event was pivotal in the development of civilisation. Perhaps, in this case, the extreme nature of this disaster led to a kind of existential crisis that resulted in a more collaborative and cohesive form of religion. And, in turn, this catalysed the formation of larger communities that could develop the specialisms displayed at Göbekli Tepe.

Göbekli Tepe might even represent a kind of nexus, or cultural ‘melting pot’, where people with diverse backgrounds, including refugees from distant lands, combined their efforts and expertise with Local Natufian survivors to achieve a grand vision. And whether or not it represents the true origin of any particular specialisation is perhaps not the key issue. More important than that is the strong sense of community that it demonstrates. Perhaps it is this sense of community that fuelled the Neolithic revolution that followed. Therefore, it can be argued that through its destructive capacity, the Younger Dryas event might have forced, or persuaded, mankind to cooperate in larger numbers, to civilise, in order to survive and recover via the medium of religion.

The key factor, then, in Göbekli Tepe’s importance is possibly its expression of an organised religion, as this likely drove people to cooperate through a shared belief system, and shared vision. The origin of this belief system, which appears to be a kind of comet cult with astronomical mythology, predates Göbekli Tepe according to Witzels’s Laurasian hypothesis. However, the construction of Göbekli Tepe, triggered by the Younger Dryas event, appears to represent a step-change in the importance and organisation of this astronomical cult.

It appears, then, that the destructive capacity of comets led to a strengthening of existential inquiry, which today we would call religion. This organised religion, mutated by time and distance into various guises, continued through to the Bronze Age, and shaped later proto-Indo-European and proto-Afro-Asiatic cultures. It appears the Younger Dryas event and Göbekli Tepe represent a step-change in religious or mystical belief and organisation that defined later civilisations and continues to resonate today.

But, this remains quite speculative, and we still do not have a proper understanding of the development of civilisation. While Göbekli Tepe suggests the Younger Dryas event might have been important, I have already argued that it cannot have been solely responsible – there must be other important factors in play.

Giant Clusters of People

Even if the Younger Dryas event was significant, pivotal even, we still need to find evidence that supports the view that a change in cognition, or religion, can lead to larger communities. It is an easy thing to say, and it might appear obvious, but is there any evidence that actually supports this case? How can a change in cognition lead to larger communities of specialists?

Furthermore, taking this view does not explain, given that there are likely to have been earlier cosmic catastrophes, why it was the Younger Dryas event only, and not an earlier catastrophic event, that led to a change in cognition sufficient to cause the origin of civilisation. If there were other events of this kind, what was so special about the Younger Dryas event?

In fact, to address this question properly, it will be useful to think again about what is meant by the ‘origin of civilisation’. It is often assumed that there was some specific trigger that caused civilisation to begin. But what if this view is wrong? What if the process is much more gradual than this? And in any case, what is really meant by ‘civilisation’? We have taken it to mean something along the lines of ‘the emergence of specialisms within larger communities’. But this is quite a vague definition, open to interpretation. Can a more precise definition be found? Probably, to make sense of it all, we should go back to basics. What is meant by a large community of specialists?

In the animal kingdom, especially within ape communities, some of the elements of civilisation are already observed. For example, chimps and gorillas form hierarchal communities of several dozen. They typically have a male leader – the chief chimp or the silverback gorilla. But this falls far short of what we instinctively think of as ‘civilisation’.

Nevertheless, it is a useful starting point for thinking about civilisation in a human context. We can think of this kind of grouping, a small tribe of several dozen individuals with a dominant leader, as the most basic kind of organisational group within a human culture.

Probably, when our species first evolved, we were organised into many relatively small tribes each led by one or more dominant elders. We hunted and gathered our food, made temporary dwellings, and migrated as nomads. In order to prevent in-breeding, these tribes would not have been entirely isolated. They would have encountered each other frequently along their travels, and interbred to keep the gene pool healthy. And, of course, in addition to this largest organisational unit, the tribe, there would have been smaller groupings all the way down to individuals. We see this amply demonstrated today. Although most of us now live in cities, there remains a major fraction of the population who continue to live more isolated lives in the rural environment whilst still taking full part in society as a whole.

Indeed, we see this most basic level of organisation, the small tribe, even today, among some cultures in South America, Africa and New Guinea.

Some of these so-called ‘lost’ tribes continue to live in the remotest regions without any contact with the broader world. They do not take part in our modern global society, and can truly be considered separate cultures.

Clearly, they are not what we mean by ‘civilisation’. Despite the fact these lost tribes have a specific culture, which encompasses their language, traditions, mythology, artistic expression and understanding of the world, and even though their tribes will probably include individuals with specialist skills of some form, such as chief, shaman, weaver and so on, we do not consider these remote tribes to be civilised.

So, what actually is civilisation? It seems the vague notion of ‘larger communities with specialists’ is not particularly useful, because it doesn’t spell out how large a community needs to be, or which specialisms are needed, to be considered civilised. And in any case, it is practically impossible to identify all possible types of specialisation or hierarchal organisation, with all their various nuances, to produce a definition of civilisation on this basis.

So, let’s forget about a definition of civilisation that requires specific hierarchies or specialisms. This road leads nowhere except to prejudice. Instead, let’s use the definite and countable attribute of size as a definition of civilisation. This is much easier, and therefore more useful. In fact, the etymology of the word ‘civilisation’ comes from those who reside in ‘cities’. So, population size is an instinctive indicator of civilisation.

And, rather than becoming bogged down in setting a specific population, or population density, as a target above which civilisation is defined to exist, and below which it doesn’t, let’s instead take a relative definition. Therefore, let’s say that, relative to a specific environment, a culture organised into small tribes is less civilised than one formed of much larger tribes. The nature of the environment is important because it can have an influence on the group size it can support. This means the size, or degree of civilisation, of communities within different environments should not be compared. It’s all relative.

However, if we consider two cultures within similar environments, whose communities have very different sizes (or more properly, size distributions), we can say the one with larger groups (on average) is more civilised. This seems like a good definition. Cultures formed of larger groups must be more organised, and therefore civilised, to be able to exist within the same environment. The typical size of the least civilised tribe, judging from archaeological evidence of hunter-gatherers and existing lost tribes, is in the region of 50 to 100 people.

Ultimately, then, it comes down to population size. What we need to do is try to understand why communities with specific sizes form. If we can understand this, then we can understand the origin, or more properly, the development of civilisation. Essentially, we need to understand how giant clusters of people form.

Now, it turns out that in the realm of physics, the phenomenon of clustering is fairly well understood. Because stable clusters are seen to occur for all sorts of different physical systems, from atomic nuclei, which are essentially just clusters of more fundamental particles known as protons and neutrons, to stable protein clusters within cells, known as ‘organelles’ which have important roles in biology, physicists have looked at the question of how stable clusters can form in a very general sense and have come up with some important insights.

In fact, this is an area of research in which I specialise. In my particular case, I was interested to know how giant stable clusters can form in aqueous solutions of small soluble molecules, like amino acids, the building blocks of proteins and therefore an essential component of life. The problem here is that small soluble molecules like amino acids have traditionally been assumed to form uniform dispersions within water. But this view might be contradicted by recent experiments. Instead, it appears giant clusters form in these solutions, which are stable, and my recent research has sought to try and understand this. It might even be important to the origin of life.

I find it quite satisfying that the same kind of insights into these problems can also help to understand the development of civilisation. There is a deep kind of ‘universality’ here. We see stable clusters form again and again in science in a wide range of completely different systems. Why is this?

The answer, or one answer, to this question is that when the particles of an evolving system are attracted to each other when they are close together, but repel each other, if only very slightly, when they are further apart, then we can expect stable clusters of particles to form. It doesn’t matter what kind of particles they are. In our case, when thinking about civilisation, we can equate a particle with a person. So long as there is a kind of interaction between particles, or people, that is slightly repulsive at long range and fairly attractive at short range, if the particles are mobile so that the system can evolve, and the repulsive and attractive interactions are not too strong, then for these systems we expect large stable clusters of particles, or people, can form under the right circumstances.

Therefore, populations of animals, including humans, have this same kind of clustering behaviour because the underlying interactions between individuals, in a very average sense, have a long-range repulsive component balanced by a short-range attractive part. Of course, this assertion needs some justification.

Consider our species, although these observations are quite general across species. We can say that between a pair of individuals, in a very average sense, a weak long-ranged repulsion exists because of the competition for resources. We all need to eat and drink. In an average sense, the closer two people approach each other, the more effort they need to expend to find food and water. This effect is ‘always on’. It doesn’t matter what culture we live in, regardless of its sophistication, we compete for food and water. The more food and water one person consumes, the less is available to other people nearby. In an average sense, this is equivalent to a long-range repulsion. It is long-ranged because the area of land we each scour to search for food and water is large.

This concept of competition for resources has been generalised, for humans in modern societies, to include all the resources we consume, and is known as our ‘ecological footprint’. It is estimated that our personal ecological footprint today ranges from about 0.5 hectares for people in the poorest countries, to as much as 10 hectares for people living in the richest (and most wasteful) countries. This is the amount of land needed to sustain each person for one year. Dividing this area by 365.25 gives the daily ecological footprint.

Let’s take 1 hectare, which equates to a circle with diameter about 113 metres, as the annual ecological footprint of an early hunter-gatherer. This is the amount of land needed to support each hunter-gatherer for one year. For the time being this estimate is good enough – we are thinking conceptually here, we don’t need to know precise values. Although this area seems like a lot, it doesn’t mean that hunter-gatherers could not approach each other closer than 113 metres. That’s obviously nonsense. What it means is that as more hunter-gatherers crowd together within a community, the further they each need to travel, on average, to find food and water. And as travelling to find food and water takes effort, all other things being equal, it will be avoided. Therefore, the competition for resources drives people to form smaller clusters, or communities.

This repulsion between individuals due to competition for resources is weak and long-range, with a distance equal to the maximum distance travelled each day to find food and water, and an ‘intensity’ equal to the daily ecological footprint divided by the average area of land searched for food and water each day. To see this, consider the following example. Compare the effort expended by hunter-gatherers who hunt on foot to those who hunt on horseback. Those on horseback have a much larger range, and therefore they experience the competition for resources over a much larger area each day. At the same time, because their ecological footprint is nearly the same (apart from feeding a horse), it means the intensity of their mutual repulsion is less for those on horseback. In other words, finding food and water via horse-riding is easier, and therefore the competition for resources is less intense. This means horse-riding offers an advantage that enables larger communities to develop. Of course, this assumes a very average view. We are thinking in terms of averages over people in a population as well as an average over each day in the year.

Now, if we only ever experienced this long-ranged repulsion we would forever roam the wilderness as individuals. We would be trying to avoid each other as much as we could to prevent overlapping the areas within which we can search for food and water each day. The closer we approach each other, the stronger this repulsive urge becomes.

Of course, this is not what happens – we do not all roam the wilderness as individuals. Even the least civilised hunter-gatherer tribes, both ancient and modern, have populations of around 50 to 100 people. Why? Obviously, it is because, on average, we like to be together. We enjoy each other’s company, we benefit from helping each other and, of course, we need to procreate. In terms of interactions between individuals, in a very average sense, we can express this desire to be together as a short-range attraction. It is short-ranged because the behaviour that leads to this attraction generally takes place at short-range, whether it is having a conversation, helping someone skin a goat, or having sex.

It is quite clear, then, that in a very average sense we can view people as having strong short-range attractive interactions and weak long-range repulsions. And, as has been said, these kinds of system are known to exhibit giant clusters provided neither the attractive nor the repulsive interactions are too dominant. This idea, of a competition between a long-range repulsion and short-range attraction, has already been applied with some success to model clustering in plant ecologies, but here we are using it to understand the formation and stability of human communities.

In fact, the clusters that form will have a preferred size. This is because, on the one hand, if the cluster gets too large then there is more to be gained by splitting into two separate clusters than by growing further. That is, for large clusters the long-range repulsions dominate and force the cluster to separate. On the other hand, if a pair of clusters is too small, they have a lot to gain by merging. That is, for small clusters the short-range attractions dominate and cause small clusters to merge.

Between these cases there is a ‘sweet spot’, or optimal cluster size, that is preferred where the short-range attractions and long-range repulsions are balanced. The stronger the attraction, the larger the cluster, while the stronger the repulsion, the smaller the cluster. These forces balance against each other to determine a specific optimal cluster size.

A survey of the size of hunter-gatherer archaeological sites illustrates this concept nicely. Analysis of many hundreds of such sites indicates that, because resources vary in their availability significantly throughout the year, hunter-gatherer tribes tended to split into smaller groups during the winter. These would then merge again in the spring or summer. Typically, hunter-gatherer group size appears to have been in the region of a few dozen in winter, while it could be a few hundred in summer. Of course, there is a lot of variation in these sizes; these are just estimated averages.

It appears, then, that the same basic principle applies to us as it does to protein molecules inside cells or to nuclear particles within an atomic nucleus. The same basic physics produces the same basic behaviour.

The Development of Civilisation

Now that it is understood why humans form clusters, or communities, we can begin to understand why the size of these communities can change, depending on their circumstances. We can begin to understand how civilisation, defined as the trend towards the formation of larger and larger communities, can develop. Essentially, we need to think about the factors that influence, in a very average sense, the strength of the short-range attractions and long-range repulsions that exist between us. Pulling together all the strands of evidence leads to the following synthesis, a proposal for a new understanding of the development of civilisation.

Beginning with hunter-gatherers with only very basic Stone Age technology, it seems the balance between the competition for food and water and the desire to be together, for all sorts of reasons, tends to lead to community sizes from a few dozen to around a few hundred people, depending on the season and environment. Any increase in community spirit inevitably leads to larger communities. Likewise, any new technology, such as horse-riding, that reduces our ecological footprint or increases the range over which we can search for resources, will also increase community size.

With this better understanding that civilisation does not have a single point of origin, but is instead a continuous process of development, we can see how it might appear that the Younger Dryas event was particularly important. For hundreds of thousands of years before this event, mankind simply did not have sufficiently advanced technology to support large communities. The competition for resources within and among tribes was so great that tribes were limited to little more than a few hundred people or so. And the effort expended in searching for resources, for survival, limited the opportunity to develop new technologies. And moreover, perhaps our community spirit, defined by our Gondwanian mythology at that time, did not generate a strong motivation for larger communities. We were caught in a culture trap.

Then, perhaps around 50,000 years ago, Satan entered the inner solar system. This possibly led to a change in existential enquiry, a development in astro-mythology to the Laurasian form, that dispersed with us as we migrated across the Eurasian and American continents. Anthropologists currently call this change of human behaviour at this time, which resulted in the great Palaeolithic artworks discussed in Chapter 9, the ‘cognitive revolution’. Although its cause is currently unknown, some suggest it might have been triggered by a genetic change. That is, by evolution. However, there is no evidence for this within archaic human DNA. The so-called ‘cognitive revolution’ 40,000 to 50,000 years ago does not appear to have a biological trigger. It is therefore another open problem for which I suggest a potential solution.

This supposed cognitive revolution, perhaps triggered by Satan’s appearance, might have led to a significant advance in civilisation 40,000 to 50,000 years ago were it not for the regular bombardments and abrupt changes in climate, known as Daansgard-Oeschger events, caused by debris falling off Satan. Our ancestors memorialised these catastrophes wherever they could with great works of art, but the disruption to climate and local environments impeded the invention of technologies for advancing civilisation, especially agriculture. Whenever the green shoots of civilisation emerged, they were buried by the debris of another catastrophe. People continued to migrate in search of fresh land. Large animal populations across the globe also suffered, although it appears Africa got lucky. Through dint of its huge size, equatorial location and pure good fortune, the African continent avoided the worst effects of these bombardments.

Eventually, the bombings became less regular and severe as Satan’s mass dwindled, and the ice age began to thaw. In a few places around the world semi-sedentary, and then fully sedentary, communities formed that began to develop megalithic architecture, store food and experiment with cultivation and animal husbandry to supplement their hunting and gathering. Community sizes increased to many hundreds throughout the year in some places.

But then the massive Younger Dryas event happened, returning the world to a mini ice age. Community sizes initially shrank, and many people that had begun to civilise, the Natufian for example, dispersed into smaller nomadic bands as the competition for resources intensified briefly. But, this massive event also led to another change in mythology in some places. It became more organised and fearful – more religious. The bonds that tied some groups strengthened, and they gained a new identity. In places, this led to an increase in community size that appears almost like a step-change in civilisation. The earlier experiments with food storage, cultivation and animal husbandry were developed further to support rapidly increasing community sizes, and Göbekli Tepe was created.

After the end of the Younger Dryas period, when climates around the world warmed, the polar ice sheets, glaciers and Arctic tundra receded, releasing vast new ranges of productive landscape. Agriculture developed and spread rapidly outward from the Fertile Crescent propelled by the proto-Nostratic culture of the Natufian tribes. Villages became towns, and towns became cities. Before long, our astronomical notation had developed into a fully fledged writing system.

Satan continued to make his presence known through occasional outbursts that would destroy a city or civilisation here and there. Disease and starvation were rife, and people migrated en masse to find new land. War leaders took advantage of the chaos to secure their legacies. But there were no more global disasters, the land healed quickly, and civilisation survived wherever it was able.

Ultimately, Satan dwindled away, leaving little but a few relatively small inactive comet fragments embedded within narrow bands of debris, themselves orbiting within a broader disk of zodiacal dust within the inner solar system. History became legend, and legend became myth.

So, we see, according to this proposal, that the rapid development of civilisation, commonly known as the Neolithic revolution, after the Younger Dryas period is possibly a consequence of several factors that occurred together. It’s a triple whammy. There was possibly a development towards a more organised and fearful religion at Göbekli Tepe, triggered by the Younger Dryas event, that strengthened community bonds. Added to this, agriculture and food storage were already undergoing an experimental phase within Natufian communities before the Younger Dryas event, and could be developed further to reduce the ecological footprint of new and larger communities afterwards. And finally, a thaw in the ice age released vast new areas of land with temperate climates to accommodate a growing population. Although Satan continued to wreak havoc, his fits of anger were less intense than before and these new communities were able to weather his infrequent outbursts.

Judgement Day

The main issue that springs to mind when considering this proposal, founded on Clube and Napier’s version of catastrophism, is ‘Where are we in this process’? How much of Satan is left – can he cause us any more trouble?

You are no doubt familiar with all the ‘crank’ predictions that the end of the world is nigh. But, as a physicist, I know that predictions of this kind must be wrong. The best place to look for answers to this question is in the scientific literature. In particular, we should seek answers from the astronomers that have made it their life’s work to study the Taurid meteor stream. What do they say?

The Taurid meteor stream to which Satan has decayed is expected to contain one or more dense ‘filaments’ in which most of the remaining large pieces of debris reside. But each dense filament is surrounded by a much larger and diffuse debris field consisting mainly of smaller pebbles and dust. These filaments precess just like comet Encke. This means that, most of the time, we encounter only diffuse regions of these debris streams, observed as meteor showers. Occasionally, we encounter a larger object which appears as a bright fireball. Rarely, we collide with a Tunguska-sized object.

However, due to precession we will eventually encounter the dense core at the heart of each filament. This will manifest as episodes of increased risk, lasting for hundreds of years each, when the orbits of these dense filaments intersect Earth’s orbit. If we are lucky, we will pass through them relatively unscathed. But we cannot rely on luck. Obviously, we would like to know when the next filament will intersect Earth’s orbit, and how much debris remains within it? What are our chances and how long do we have to prepare?

Unfortunately, none of these questions can be answered with much confidence. But, it appears that Satan has decayed largely to dust already, leaving behind an assortment of mainly dormant or extinct comets with a wide range of sizes. Spending on asteroid detection has focused on spotting the largest objects in near-Earth orbits, and we have found most objects over one kilometre in diameter with the potential for globally catastrophic consequences. There are about 1,000 of them. Using Opik’s formula, which provides an estimate of the probability of a collision with any one of them, we should not expect to collide with any of these within the next few hundred thousand years. Any comet fragment, such as Encke, among this tally should decay to dust well within this timescale. So, it appears, Satan has done his worst.

But, there are an unknown number of smaller Tunguska-sized chunks of 100 metres or so in diameter remaining in these filaments. Because their number is unknown, the risk they present cannot be estimated. However, as the years tick by, the cometary fragments among them, and their concomitant risk, will also continue to decay.

As the risk is concentrated within those eras when a dense filament is close to Earth’s orbit, we should focus on their timing. Again, this is not known with much confidence. The cometary scientists who lead this research area, Clube and Napier and their colleagues, suggest comet Encke is associated with the main filament at the heart of the Taurid meteor stream. This means we can use Encke’s precession to track the likely evolution of this main filament.

Currently, comet Encke’s orbit precesses such that it intersects Earth’s orbit roughly every 3,000 years. Although we do not expect to collide with Encke itself, its debris field will present a period of increased risk lasting around 500 years. We also know that our next passage through this dense filament will occur around 3000 AD, or slightly before. We therefore have plenty of time to prepare for this episode, nearly 1,000 years into our future.

However, the filament surrounding Encke is not the only one out there to think about.It is likely there are at least eighteen large comet fragments associated with Encke, and they all have slightly different orbits with different rates of precession. So, even if Encke is surrounded by the main filament of debris, there are many others that pose a risk, and we know very little about any of them.

If this assessment of Encke’s precession and its role in the development of civilisation is correct, then we should see a repeating pattern of climate events and cosmic catastrophes roughly every 3,000 years.

Working backwards from the next expected episode just before 3,000 AD, we should expect to see episodes of catastrophism late in the first millennium BC, then again late in the 4th millennium BC, the 7th millennium BC, the 10th millennium BC, and so on. Is this pattern actually observed?

The expected episode around 0 AD is not seen in the Greenland ice core record – there is no corresponding dip in northern hemisphere temperature, although this period does correspond to the rise of Christianity and some severe outbreaks of plague across Eurasia. This is probably good news for us, as it implies Satan might have almost dwindled away to nothing and his fury is nearly spent.

However, the expected late 4th millennium BC episode, which marks the transition from the Stone Age to the Bronze Age and the origin of the Kurgan migrations that spread proto-Indo-European culture across northern Europe and central Asia, is clearly recorded by ice cores (see Figure 44). .

Again, the expected late 7th millennium BC epoch of catastrophism likely corresponds to the 8.2 kiloyear event. This episode directly precedes the Anatolian farmer conquest of Western Europe that almost wiped out female west European hunter-gatherers, and might have occurred simultaneously with several major geological events, such as the Storegga Slide, the Black Sea inundation and the final collapse of the Laurentide ice sheet. It might also have brought the first great Egyptian civilisation beside the Nile to an end, leaving the enigmatic Sphinx of Giza as an enigmatic token.

The expected late 10th millennium BC epoch of catastrophism might correspond to the end of the Younger Dryas period and/or to a severe climate event shortly after. Likewise, the expected late 13th millennium BC episode might correspond to dramatic climate oscillations before the Younger Dryas event. Finally, the expected late 16th millennium BC episode of catastrophism might correspond to the event recorded by the Lascaux Shaft Scene at around 15,200 BC.

So, our expectation of disasters every 3,000 years, beginning around 0 AD going backwards, does appear to be borne out. However, the Younger Dryas event itself does not fit this pattern. Possibly, it was caused by collision with a Taurid debris filament that does not precess at the same rate as Encke.

Therefore, apart from the largely missing period of catastrophism expected around 0 AD, it can be argued that a significant stream of debris might reside close to comet Encke and have caused several episodes of catastrophism over the last 20,000 years. However, this is hardly a scientific case, as there are many other large bodies in Encke-like orbits and many other periods of rapid climate change through the Holocene period. Teasing apart the connections between any of these is a complex research project that has yet to be undertaken.

Once again, past episodes of cosmic bombardment can only be confirmed by locating the relevant geochemical evidence within sediments and ice sheets around the world, and until these studies are performed we must keep an open mind. Prediction of any future episodes is an equally complex problem requiring much greater knowledge of the dense filaments of the Taurid meteor stream. Nevertheless, adopting the precautionary principle, we should keep a close eye on debris around comet Encke, as well as all the other large objects in the Taurid meteor stream.

Normally, any evidence of cosmic catastrophes over the course of human civilisation is interpreted as being the result of other causes. Clearly, it is now important that existing scientific data indicating prehistoric and historical catastrophes, including major and correlated episodes of cultural transition, civilisation collapse, population migration, climate change, earthquake, war, famine, pestilence, conflagration and flooding, is reassessed to properly consider cosmic bombardment as a possible causal mechanism.

Written by Martin Sweatman in "Prehistory Decoded", Matador, UK,2019. excerpts chapter 12. Digitized, adapted and illustrated to be posted by Leopoldo Costa.