Prehistory

For an overview of human deep history see the article human origins and migration. and for general background the university of here.

The article you are reading establishes a broad context for human biological and cultural evolution.

Humans arose in Africa about 2 million years ago, diversifying into at least five species and migrating to other continents. Modern research is currently assessing the factors, like climate change, that have dictated the pattern and timing of this global migration including the distribution of our own species Homo sapiens.^[2][3]

Genetic anthropology

Since the late 1980s the patterns and dating of ancient human migrations across the world have been coming into focus due, in large part, to the analysis of genetic markers (mutations that remain in all subsequent offspring) on female mitochondrial DNA (mt DNA) and male Y chromosomes (Y-DNA). Genetic anthropology, as it is called, uses these markers to identify genetic lineages, where the lineages originated, and their approximate age. This, together with ever-improving archeological research, has given us a fairly secure insight into broad prehistoric human migration patterns across the globe. In 1987 the first human family tree was produced based on mtDNA and tracing all humans back to a single female ancestor known as ‘Eve’.

Use of fire

For Australian Aboriginal use of fire see Firestick farming.

About 300,000 humans would have been hunted by other animals, sometimes feeding off the remains of kills by top predators, especially the marrow remaining in the bones. Humans were middle predators and marginal but by 100,000 had become top predator.

Evidence for the human use of fire appears in the archaeological record about 300,000 years ago. Fire provided not only light and warmth but it could be used as a weapon against predators, as a means to clear land and access food. Cooking permitted the rapid consumption of relatively unpalatable wheat, rice, potatoes and other foods. Cooking was a technology of great importance since it was a form of pre-digestion while at the same time killing all kinds of germs and parasites. Other greater apes spent long periods eating and digesting food while cooking allowed rapid digestion and hence extraction of energy. Strong and large crushing teeth were no longer necessary and as digestion was easier there was a reduction in the length of the intestines (the second largest energy consumer of the human body after the brain). Perhaps this was a contributing factor to the increase in size of the brain.

Domestication of fire was an extension of natural abilities, one of the earliest and most impactful human technologies after the use of tools. While one human body with simple tools could have a negligible effect on the environment, a single human using fire could transform an entire ecosystem.

Emergence of Homo sapiens

Homo sapiens first appeared about 200,000 years ago and by 150,000 BP East African members of the species appeared very like anatomically modern humans. Archaeooogical evidence indicates several waves of the species out of Africa one extending to the Arabian Peninsula and another as far as the Middle East but all, appear to have been abortive, probably driven back by other species.

About 100,000 years ago there were at least 5 human species alive: the stocky Homo neanderthalensis in cool-climate northern Europe; the slight H. solensis in Java, the dwarf 1 m tall H. floresiensis on the island of Flores, H. denisova in Russia, and the massive short, muscular, and heavy-browed Homo erectus (surviving from 1.5 million years ago to about 50,000 BP) found from Europe to Asia, in China (as Peking Man, dating back about 750 kya)^[1] and Indonesia (Java Man, dating back about 1.9 million years). Several species also evolved among those that remained in East Africa.

Our particular species, Homo sapiens, arose in East Africa 200-150 kya.^[4] and by 10,000 BP was the sole remaining species. It is evident from the archaeological record that in the period from 125-60 kya years ago there were several waves of migration of H. sapiens out of Africa, these populations replacing earlier hominids like H. neanderthalensis (Neanderthal Man). Though there were multiple migrations (for example, archaeological artefacts show earlier waves of H. sapiens on the Arabian peninsula dating back about 125 kya) modern genetic research now largely supports the ‘Out of Africa’ theory indicating that the unique lineage giving rise to all modern humans left Africa relatively recently, about 60-70 kya.

It is remarkable that while Homo sapiens is first recorded in northern Europe c. 42-43 kya, Britain about 25 kya, North America about 18 kya,^[5] South America about 12 kya – Aborigines had populated Australia by about 55 kya reaching Tasmania by about 35 kya.

Cognitive revolution

The human mind is noted for, among other things, abstract thought, hindsight and foresight, memory and learning, the use of symbolic languages, reason, and creativity. But only recently have the mind and brain – whose study was largely treated as a matter for religion and philosophy – been regarded as accessible to science. The preceding behaviorism had treated what goes on in the mind as being only accessible via its external manifestation as behavior. There followed a modern cognitive revolution in the 1950s and ‘60s when scientists at Harvard University began the serious study of the contents of the human mind. This was later associated with the development of computer science.

But how do we account for the transition that occurred in prehistory as early humans, living in nature like other primates, gradually developed the capacities we associate with symbolic culture and sociality^[7] – the clever use of fire, especially for cooking, the use of written symbols and images (art, jewelry, ornamentation, sculpted figurines), the development of spoken languages that facilitated communication in larger communities with systems of religion, law, and trade , and including the communal development of tools and technologies, sometimes known as behavioral modernity.

At one time this cognitive revolution of prehistory was closely related to bio-genetic causes. Stanford paleoanthropologist Richard Klein, for example, suggested that a genetic mutation occurred 40,000 years ago, prompting a revolution in thought and behavior.^[8] Recent thinking inclines to the view that modern cognition was likely already in place when Homo sapiens emerged. That the development of sociality, symbolic communication, and technology – as the elaboration and complexification of shared symbol systems (social evolution) – rather than being the result of biological changes to the brain, is more likely to have involved the synergistic and cumulative impacts of collective learning. Perhaps the most obvious of these is technology whose exponential acceleration in sophistication and complexity has created a corresponding increase in the speed and scale of its impacts.

About 70,000 years ago H. sapiens moved out of Africa to spread across Eurasia. Anatomically modern humans became the most widespread animal on earth spreading to Australia in about 55,000 BP (and eventually America in about 15,000 BP) and in the process out-competing, or exterminating, all other human species. There is a correlation between the time when human species died out and arrival of H. sapiens in their homelands. H. neanderthalensis died out – it helped us see ourselves as very special. H. soloensis disappeared in about 50,000 BP when H. sapiens arrived in Java, and Denisovans about 40,000. 12,000 last H. floriensis.

Physically there was a need to adapt to cold climates and new ecosystems. There is evidence of an Indonesian seafaring society using sailing craft; the first needles appear in cold climates where they are used for clothing, boots and tents; oil lamps were made, burning animal fat and facilitating life in caves. From this period on there was a steady modification of stone knives and spear points, we see the first evidence for cave art, jewellery, trade, religious belief and large social groups.

Though there is little direct evidence it is assumed that these changes were linked to a change in cognitive ability, an increased ability to think, learn, remember, and speak language. Their brains and bodies were same as ours.

Language

At the core of the cognitive revolution was language which Human language, now assumed to be a key component of the cognitive revolution, had three major strengths: it was combinatorial (with just a few sounds it was possible to utter an almost infinite number of unique combinations expressing the sum of human knowledge and experience); it was highly social facilitating social cohesion and regulation; it was fictive, allowing the transmission of information about concepts and abstract objects.

For primates the maximum group size appears to be about 150. Below this approximate number it is possible to develop interpersonal relationships and establish ranking within the hierarchy. Larger numbers made this essential interpersonal connection unwieldy resulting in the creation of (often competing) splinter groups. Chimps appear to have an optimal group size of 20-60 individuals. The authority of the alpha male depends on a supportive coalition so brute strength does not always win the day. There is therefore an upper limit to the size of primate bands, this being about 150 individuals (although it is usually far fewer).

Language, through the sharing of abstract ideas (fictive stories or grand narratives) overcame the need for the close physical ties of other primates. It was the shared narratives that cemented the group, permitting a cooperative flexibility among large numbers of strangers. Once cooperation of large numbers was achieved then all the advantages of scale would follow: the capacity to construct elaborate and massive buildings, transport systems and so on. None of this would be possible with small bands of individuals.

It was this aspect of the cognitive revolution, the capacity to create a grand narrative (or common mythology) that allowed Homo sapiens to aggregate into large cooperative and flexible communities. From this, it could be argued, would flow empires and the ultimate domination of the planet. But at heart, it has been fictive grand narratives – formal religions, state constitutions, business ethics, ideologies etc. – that have created the cement for large communities to work together and exploit the benefits of scale.[1] Only H. sapiens has the capacity to speak about objects that do not exist in the physical world.

Our institutions today also depend on such mythologies. Within a company hundreds of thousands of strangers are employed. What is BP, Walmart, Ford (factories, cars, the workers, managers or stockholders – all can be replaced and the company continue). A judge can dissolve the company although all these objects remain (limited liability companies: legally independent of the people who set up and manage them, not the founder, stockholder, owner, or manager).
Much human history revolves around persuading people to follow a myth: but when it works it has the power drives people towards common goals. [Imagined reality, social construct, a fiction]. It is not a lie but something that everyone believes in, especially its ‘priests and creators. Gods, nations and corporations. Something that does not really exist.

Beginnings of cultural evolution

Primates can discover benefits in daily life that are learned and passed on to future generations. Each individual has its own personality and its own way of interacting with the environment and its fellows. However, socially learned changes in behaviour are minor in both operation and consequences. This is because behaviour is largely under genetic control: chimps do not discuss social organisation, sexual equality, new political systems: the way their society is organised is not a matter for discussion and negotiation. Change may occur but extremely slowly as a result of genetic change and in genetic time. Ancient humans changed slightly if at all. H. erectus was an extremely successful primate surviving and occupying a wide range of habitats. But throughout this period there is no archaeological evidence for any change in their way of life, for the period of about a million years the technology did not change. Similarly there are no indications of Neanderthal trade while there is evidence that it was used by H. sapiens which probably traded both goods and ideas. H. sapiens, it is known, hunted in cooperative bands comprising hundreds of people (indications of herds being surrounded, fences as traps etc.).

As part of the cognitive revolution slow genetic change had been supplemented by rapid cultural change to meet changing conditions and needs, and facilitated by language. religion was not genetic, that is, specific beliefs were not acquired at birth they were learned culturally, being passed on by word of mouth. Social change could now be fast-tracked as fictive language opened up the possibility of information storage in memory being passed on by oral tradition. Other changes could now take place in politics, economics, sexual relations, religion and so forth.

The cognitive revolution marked the first stepping of H. sapiens out of a genetically inflexible and largely predetermined form of primate existence into a world where choice and change were possible as language permitted the storage and passing on of useful information and the means to enact social change. Humans, though evolved from and part of the animal world, were now significantly ‘different’.

From the time of the cognitive revolution historical analysis would require language that extends beyond biology: it would need to understand and interpret the powerful influence exerted by abstract narratives.

Interbreeding

In about 50,000 BP H. sapiens were clearly genetically different from the Denisovans, Javans, Floresians and Neanderthals. Was there interbreeding? If so then this is a potential source of substantial genetic differences between modern humans.

In 2010 the entire Neanderthal genome was mapped and compared with people today. About 4% of people in Middle East were Neanderthal, and up to 6% of Denisovan genes occur in Australian Aboriginals. Did Denisovans and Neanderthals interbreed?

Did H.sapiens breed with the other species to merge with species in the Middle East, China. Then perhaps they replaced them, being unable to interbreed, possibly by genocide? Do particular lines have Neanderthal, Denisovan or Javan genes and therefore deeper genetic differences.

Lifestyle

Stone Age humans now had the capacity for abstract conceptual thought allowing the development of imaginitive systems of art, politics and religion. The Stone Age world remain until the advent of agriculture about 10,000 years ago so almost all of human evolutionary history occurred when the lifestyle was that of the hunter-gatherer.

Evolutionary psychology, arising in the 1960s, draws attention to our psychological origins within this period of history termed the ‘Environment of Evolutionary Adaptation’ resulting in psychological predispositions not wholly appropriate to modern life.

There is much we do not know about this period but it would appear likely that fictive imagination resulted in tribes with very diverse social structures and beliefs. It is perhaps unlikely that communities were based around the nuclear family, probably being sexually promiscuous with no fatherhood, and child-rearing a matter for the tribe. Even so, close and intimate living would have resulted in codes of behaviour developed to protect the group.

In spite of social variety there do appear to be some broad Stone Age characteristics:

• Small bands with maximum number of several hundred
• Domestication and coevolution with wolves by at least 15,000 BP (assisted in hunting, fighting, and as an alarm)
• High intimacy with neighbours both enemies and source of trade, occasional cooperation, political and practical ideas
• Daily life determined by the seasons and the seasonal food supply – migrations of animals and the growth cycles of plants: longer camps near rivers and sea where food supply more stable
• A wide diet with gathering generally more important than hunting
• High degree of fitness(on average taller than today) and strength with detailed knowledge of the land and its contents
• Average brain size has decreased since the agricultural revolution
• A relatively leisurely lifestyle the result of mostly good food supply and living simply
• Little disease as modern diseases (zoonoses) are largely contracted from domesticated animals and lack of hygiene in cities and passed quickly on in large groups
• High rate of death in childbirth and high rate of violent death
• High susceptibility to drought, famine, fire and natural disaster

Up to the agricultural revolution population probably did not exceed about 8 million individuals.

Mental life

We know very little about the fictive world of prehistoric humans and can surmise that there would have been considerable variation from one group to another. A little archaeologcal evidence and modern contact with hunter-gatherers suggest that they were animists. Both the living and inanimate worlds were inhabited by spirits with human-like emotions and desires. Communication with this world was possible, often through someone with skills in this field, like a Shaman. Spirits often needed, like humans, to be appeased, admired, and feared. They were therefore the object of sacrifices, rituals and ceremonies.

Importantly prehistoric humans appeared to exist alongside these spirits and within nature; they were not morally or spiritually superior or inferior to spirits and the natural world: there was no marked hierarchy. This contrasts with later theistic agricultural societies where the status of humans and god(s) became much more important.

Interpretation of cave paintings and archaeological artifacts is thwart with speculation. Female figurines found in sites across Russia and Europe and long assumed to be an indication of matriarchal societies based on fertility and a female goddess, have also been interpreted simply as male Stone Age pornography.

There are commonalities across the world like the hands appearing on cave walls in Australia that also occur as 8000 year-old cave decorations in Brazil, about 30,000 years ago in Chauvet-Pont-d’Arc Cave
in southern France.

Politics

We have little certain knowledge of family structure, attitude to private property, frequency and intensity of warfare. Burials dated to about 30,000 years ago indicate some hierarchical structure. Anthropologists in northern Australia and Alaska suggest that burial remains suggest high levels of violence but this is not necessarily universal. Archaeological evidence is meagre and between 20,000-10,000 findings cut both ways. Today 1.5% of deaths are the result of violence and it seems likely that figures were much higher in prehistory.

Commentary & sustainability analysis

See Sustainabilty analysis for a description of this analysis and the categories used.

Impacts

See here for an account of Aboriginal impact on the Australian megafauna
Environmental impacts made by H. sapiens on the planet were already evident in the Stone Age through the spatial distribution across the continents with the migration out of Africa starting about 70,000 ago and reaching Australia by about 55,000 BP. Although fire was capable of changing the landscape it was likely that the disappearance of megafauna in Australia began the depredation of animals that would continue to today. This was the first wave, a second wave arriving in America in about 16,000 BP when humans and likely mastodons and mammoths, crossed the Bering Strait into North America. Indications of human presence (genetically similar) are found in southernmost part of South America dating back to about 10,000 BP destroying more than half of the genera of megafauna (34/47 in N America and 50/60 in S America) in a couple of thousand years. It appears that prior to the Agricultural Revolution about half of the animals weighing more than 50 kg in adulthood had become extinct, probably due to human predation. The third wave of animal extinction due to humans would occur as islands were occupied as part of imperial colonisation during the 18-19th centuries, even large islands like Madagascar (500 CE) Today we see a further devastating wave which is mainly the combined consequence of exponential population growth, highly efficient technology and industrial agriculture.

Population

Estimates of life expectancy of hominids on the African savanna between 4 million and 200,000 years ago was 20 years, the population renewing about five times every century. Over the same period population size possibly fluctuated from about 10,000 to 100,000 individuals. 70,000 years ago the population was about 1 million people, about the same as Rome at the height of the Roman empire.

A sustainability analysis would include an appraisal of the consumption of biophysical resources – energy, water, materials, food, biodiversity, technology (science), affluence, social organization, transport & communication, education, law, health,  & ideas.

Key points

• The cognitive revolution that occurred about 70,000 years ago was probably a consequence of the development of language

• Language (with its almost infinite possible combinations of sound) allowed the transmission of vast amounts of information; it was a highly social activity serving to both cement and regulate the group; it permitted the creation of shared fictive stories (grand narratives)

• Grand narratives (common mythologies) cemented people together and facilitated flexible cooperation among large numbers of people

• Other primates with a band size not exceeding about 150 individuals were unable to compete with such large groups and it was possibly this that allowed Homo sapiens to dominate planet earth (fire, reason and cunning)

• The cognitive revolution allowed social change to take place more as a result of cultural rather than genetic change

• Knowledge of behavour, social structure, religion, and family life are all very poor for the period known as the Environment of Evolutionary Adaptation that was the cauldron for our present-day human nature

• From the time of the cognitive revolution about 70,000 years ago historical analysis would require language that extends beyond biology: it would need to understand and interpret the powerful influence exerted by abstract narratives.

First published on the internet – 1 March 2019

. . . 6 July 2023 – minor edit