Introduction

The interplay of change and continuity is a condition of human life, one that is as insistent as the passage of the years, the rhythm of the seasons and the passing of generations. Alongside the continuities stemming from earlier adaptation, from established practices and from the cultural and psychological habits of referring to the past and being reverential of it, human history shows a continuing capacity to adapt to the environment, displays the mechanics and settings of life, indicates the power and structure of society and reflects the ways humans think and are taught about life.

Humans need this ability to adapt because they are not well-suited to live on most of the planet without the help of technology. They cannot fly unaided, nor can they live under the water which covers the majority of the earth. Although fish and rainwater can be obtained while on boats, it is difficult to live permanently on the water surface. Part of this water is frozen as ice, and humans cannot stop more of this water freezing in the winter. This is true in particular of the Arctic Ocean.

Deserts like the Sahara have too little rainfall to support much life, but humans have nonetheless found a way to survive in them

Much of the land surface is intractable because it is too cold or hot, or arid or mountainous for habitation. Antarctica, a large and very cold continent, was uninhabited until recent scientific stations were established. It was not until 1912 that the Norwegian Roald Amundsen became the first human to reach the South Pole, three years after the American Robert Peary had been the first to approach the North.

A lot of the world’s land surface does not support much vegetation, or enough animal life for more than a small population of hunters. In deserts, of which the largest is the Sahara in Africa, there is too little rainfall or soil to support abundant life, plant or animal. Large ones can be found elsewhere, including the Gobi in Asia, the Atacama in South America, the Gibson and Simpson deserts in the interior of Australia and the deserts of the south-west of the United States. Europe is exceptional in not having deserts. Humans do live in deserts and have adapted to them. The populations involved are generally small and the problems posed, notably of water availability, very serious, although the very large city of Los Angeles grew with the help of water from Owens Valley.

Roald Amundsen was the first person to reach the North Pole, in 1912

Beyond supplying water through irrigation and cutting down trees, humanity’s ability to change the environment on a large scale was restricted for much of history. It was not until the late 19th century that the advent of more powerful explosives made tunnelling under the Alps possible, the first example of such significant man-made change to the environment. Projects of truly great magnitude, such as the Panama Canal, showed that humanity lacked the necessary organizational sophistication even into modern times: the French began the construction of the canal in the 1880s, but it was only finished by the Americans in 1914, after the loss of many lives to malaria and yellow fever. Until recently, humans have also had scant ability to understand changes in the climate and weather, let alone to try to change them.

Separately, humans have long faced challenges created by the organization of our species as social creatures. Humans need to be social in order to have children and to protect them during their long period of vulnerability. Tasks such as competing with other animals that are physically stronger, for example lions, and providing protection from them, require co-operation. Agriculture and warfare, later developments, need an even higher level. The structures of society which developed are inherently competitive with other human groups. The idea that humans were originally peaceful, and only became warlike due to social conditioning, is no longer widely held. Such a view is more reflective of the Biblical aspirations focused on the Garden of Eden and the utopian thoughts of the 1960s and 70s than of the surviving evidence.

The Panama Canal was completed in 1914 – an instance of humans radically changing the world around them

In turn, this competition, and the social structures that result from it, shape the norms that guide human assumptions and actions. What is the purpose of life? How are the gods, or God, to be satisfied? How should rival gods and humans be treated? These norms, expressed in religious beliefs and social practices, help humans understand their environment and, in particular, determine how best to respond to the social aspects of existence. There has never been universal agreement on these points and that they have led to widely varying political ideas and practices only makes them more significant.

Returning to ‘prehistory’ (which itself is very much a present-day concept), adaptation to the environment rapidly became supplemented by attempts to mould it to suit human requirements and those of the crops and animals used by humans, a process that was in turn driven by the need for resources and space. The moulding came to be shaped by ideologies and accelerated by the development of information storing and transmitting systems such as writing. The movement of early peoples shows clearly the need for resources and space, such as in the hunting of animals across long distances or in patterns of seasonal migration. Humans, though, did not only seek to modify their environment, but themselves were changed by it. For example, humans in areas with relatively low levels of sunlight developed genes linked to lighter skin to absorb more Vitamin D. This led to changes in Europe to lighter skin pigments around 7–8,000 years ago, a change which appears to have occurred first in Northern Europe.

We cannot always understand the adaptions made in the past, including their understanding of the world, so mysteries like the Nazca lines of Peru remain

Humans were not the only species adapting and evolving, but their greater development of social skills, notably in communication and organization, made that adaptation particularly successful. In one sense, the modern era began when humans became the most successful mammals. Birds had a greater range and could readily organize to act in groups, but humans acquired the power to dominate. They also became the species with the largest colonies of omnivores, no longer bound to a specific food source like most other carnivores or herbivores. The increasing size of those colonies, from prehistoric bands to modern mega-cities, and the power that it has given to our species to shape our destiny is one of the most underestimated aspects of human history.

Consider the related effectiveness of species and its consequences. This book will work if it makes you think – think not only about what is written here, but also about what you have experienced, and the world around you. If you disagree with the views presented, think why, and contribute to understanding by articulating your view.

Prehistoric Humans

10 Million Years Ago–10,000 bce

Early hominids lived among the stalactites and stalagmites of Kent’s Cavern, the impressive cave system at Torbay in Devon, England. The caves gave them shelter from the wet of south-west winds and opened to the light from the east. Now the caves offer an inspiring visit for tourists and a challenge for artists; but, for most of their long human history, they reflected the struggle of man to adapt to the land and face the opportunities and problems it posed.

Early Humans

Most of the earth’s history, and that of life on earth, was over long before the appearance of humans. When the magma cooled to form the earth’s crust, when the amphibians developed and left the primeval oceans, and as geological ages succeeded one another, there were no humans. Nor, as the dinosaurs dominated and then lost their sway, were humans among the first of the mammals to evolve. While the first reptiles appeared about 310 million years ago, the first true mammals emerged about 220 million years ago. They were like rats and shrews.

Humans are primates, an order (or sub-division) of mammals, warm-blooded creatures whose infants feed on their mother’s milk. The first primate-like creatures emerged about 66 million years ago, about the time the dinosaurs disappeared, but the first apes did not appear until about 23 million years ago. Their relatively large brains, dexterity and social characteristics gave primates particular advantages. Originally primarily forest tree-dwellers, primates made significant adaptations for life on the ground. Early humans were faced with more open ground cover and began to walk on their hind legs, rather than on all-fours. Combined with the development of sweat glands to cool bodies after exertion, this increased human mobility on the ground and made it possible to live in different climate zones. Human brains also have a relatively large cerebral cortex, which is linked to increased intelligence, one of the keys to their success. Humans also have highly dexterous hands, which enabled them to develop and use tools much more effectively than other animals.

First Neanderthals and then Stone Age humans made their homes in Kent’s Cavern in Devon

The development of upright locomotion was an enormous step in human evolution. With its long sole and five forward-pointing toes without claws (including a big toe), the human foot provides balance and enables greater mobility. Its evolution can be traced in the fossil record in Africa: whereas the 4.4 million-year-old Ardipithecus ramidus from Ethiopia, the earliest hominin known from nearly complete fossils, has an ape-like foot, the 3.7 million-year-old Laetoli footprints from Tanzania, which are thought to have been made by Australopithecus, another hominin species, are similar to those of human footprints. Evidence for hominins (early members of the human lineage) outside Africa has also begun to emerge, strengthened by analysis of the fragmentary 7.2 million-year-old primate Graecopithecus from Greece and Bulgaria. It was from these ancestral species that modern humans evolved, first as Homo habilis and then into more recognizable human-like specimens in the forms of Homo erectus, Homo heidelbergensis, Homo neanderthalensis and, finally, Homo sapiens.

The pace of discovery and analysis in archaeology and genetics is such that theories of human origins and spread are both rapidly changing and controversial. For example, recently-discovered human-like footprints from Crete (not then an island in the Mediterranean but part of the main landmass), analysed in the 2010s, test the established narrative. Approximately 5.7 million years old, they were made two million years earlier than the footprints discovered at Laetoli in Tanzania, Africa. Their discovery has challenged the earlier notion that hominins originated in East Africa and remained there before eventually dispersing to Europe and Asia, or at least led to calls for the re-dating of that dispersal.

By about four million years ago, when a change of climate had led to the disappearance of large forests, walking on two feet had become the norm for early humans. The demands of walking upright led the legs to be developed to increase speed, range and ease of mobility, and to support the body weight. The arms instead became focused on tool-use, which appeared from about 3.3 million years ago and was vitally important to the development of humans. The first tools were simply whatever could be found, and only later became worked and specialized for particular purposes. Stone, wood and bone were the basic materials. Simple tools were followed by composite ones, which increased their usefulness and also showed a level of adaptability in humans greater than in other species. This was notably so with ‘meta-tools’ – tools used to make other tools; for example, a very hard stone employed as a kind of hammer to open nuts (rather like a hammer on an anvil) and to make stone spear tips and, eventually, metal tools. Chimpanzees can use meta-tools, as in nut-cracking, but not move further along. Human ingenuity greatly developed the potential for such tools.

Theories of Human Origins and Spread

Traditionally, anthropologists proposed that modern Homo sapiens – our own species – first arose in Africa (around 315,000 years ago) and developed fully there. It then migrated outwards, replacing other existing species, notably Homo erectus and the Neanderthals, with only limited interbreeding between species. The degree to which there was competition and conflict between the species is unclear. DNA analysis does, however, indicate some interbreeding, with Neanderthal DNA found in modern humans.

This ‘Out of Africa’ theory has been challenged by recent discoveries. Today, scholars debate between ideas of a single source for human evolution against a more complex multi-regional evolution with gene flows occurring between regions. In this second version, there is an overall evolution toward the modern Homo sapiens, but with significant regional differences occurring.

Early Homo sapiens who migrated – whether from Africa or from several regional centres – faced landscapes and shorelines very different from those today. There was also land between South-east Asia and modern Indonesia which made movement possible between the two, as also between mainland Australia and Tasmania, and a land-bridge across the Bering Strait. In this period, humans lacked boats and, when they did develop (around 50,000 bce), they were limited in their ability to confront currents and winds.

Those first boats were probably used by modern humans to reach Australia about 50,000 years ago. By 45,000 years ago Homo sapiens had reached Europe. The timing of the human settlement of the Americas has proved especially controversial. The mainstream thesis is that the first arrivals in the Americas came from Asia about 36,000 years ago, crossing a land bridge over the Bering Straits during the Ice Age, but there is an alternative argument of a spread north from South into North America. The general view is that people spread mainly from north to South, reaching Central America about 11,000 bce and the far south by c.10,000 bce.

Any map of the spread of humanity offers a misleading precision, not least because the meaning of distance was very different for people who had to walk everywhere

Evidence which pushes back the dates for the spread of humans continues to be found, suggesting that changing climatic conditions were a factor in promoting a move out of Africa about 190,000–220,000 years ago. In 2017, palaeontologists discovered Homo sapiens remains in Moroccan rock dating to about 300,000 years ago, 100,000 years earlier than the point when the species was generally credited with developing from Homo erectus. In the Misliya cave in Israel, a 175,000-year-old bone fragment from Homo sapiens has been discovered, alongside evidence of the ability to control fire and use stone-working technology.

Life as Hunter-Gatherers

Early humans were omnivores, hunter-gatherers whose varied diets and skills enabled their spread across the world. The development of weapons and the refinement of hunting techniques permitted them to hunt, and perhaps to hunt-out, large mammals such as mastodons and mammoths. In 10–9,000 bce, early settlers in North America armed with large stone points were able to kill mammoth by piercing their hide and then to cut up their bodies and thus eat them. The diet of these early humans was supplemented by hunting other animals and fishing. A burial pit found in Alaska in 2010 revealed the bones of an infant girl and another baby who died about 9500 bce, laid on a bed of antler points and weapons, and covered in red ochre. In Central America, sloths, mastodons and giant armadillos were hunted. In Europe, large mammals, such as mammoths, mastodons, sabre-toothed tigers, giant deer and the woolly rhinoceros, became extinct in the same period.

The ability to communicate through language and to organize into groups was significant in hunting these and other animals and was part of a broader pattern of social development. The use of fire was important to the human advance as it could provide protection, for example in caves, against other animals. Humans also retained useful objects for future use and performed tasks entailing a division of labour. Stone-blade technology gradually improved, culminating in microlithic flints mounted in wood or bone hafts which could be used as knives or as arrowheads.

This skill in hunting helped ensure that humans were better able than other animals to adapt to the possibilities created by the retreat of the ice sheets at the end of the last Ice Age in around 10,000 bce, the