The use of tools

It is a commonplace that humans are distinguished from other creatures by a technological ability, and man has often been described as a tool-using animal. The distinction is not entirely valid. Some animals do use tools. are the most often quoted example, stripping a twig to plunge it into an anthill and then eating the tasty termites which cling to the end of it.

A more modern example of tool-using is that of crows living in a walnut avenue in the Japanese town of Sendai. The walnuts are too hard to crack. So the crows have taken to dropping them on a pedestrian crossing where they are crushed by the passing traffic. When it is the pedestrians’ turn, the crows fly in to bear off the fragments.

But there is a difference between using a tool which comes to hand, however improbably, and fashioning one for a purpose. Shaping a tool for cutting or scraping (two basic and useful functions) is a difficult task. Such a tool must be made of a hard material, and the hardest material easily available on the surface of the earth is stone. But how does one shape a stone without tools?

The of human technology begins with the discovery of how to give stone a cutting edge. The type of stone found most suitable for the purpose is flint.

Stone tools: from 2.5 million years ago

The human discovery that round nodules of flint can be split and chipped to form a sharp edge is extremely ancient. Tools made in this way have been found in Africa from about 2.5 million years ago. Gradually, over the millennia, in an extremely slow version of an industrial revolution, new and improved techniques are developed for striking off slivers of stone.

Variations in the flints found with fossil remains (differing both in the method by which flakes are chipped from the core, and in the range of shapes created) are used by anthropologists as one way of assigning human skeletal remains to specific groups or Divisions of the Stone Age.

In the earliest periods a single tool is usually made from the core of the flint, resulting in an instrument that can be used in a fairly rough manner for either cutting or scraping. Hundreds of thousands of years later, craftsmen have become skilled at forming the flakes themselves into implements of various kinds, producing specialist tools for cutting, scraping, gouging or boring, as well as sharp points for arrow and spear heads.

These sophisticated stone tools, in their turn, make it possible to carve materials such as antler or bone to create even sharper points, or more complex shapes (such as hooks or needles).

The predominant use of stone as the material for tools has caused this period to be known as the Stone Age. It represents by far the greatest part of human history, spanning more than 2 million years to a time only a few thousand years ago.

The Stone Age includes all human development up to the point which one might describe as the beginning of civlization. It has inevitably proved too loose a term and has been much subdivided (see Divisions of the Stone Age).

Global cooling: from 1.7 million years ago

It is about a million years ago that our ancestors, in the form of Homo erectus, first move out of Africa. At that time the planet is undergoing a series of slow but fairly drastic temperature changes, in a long sequence of glacial periods (also known as Ice Ages) interspersed with warmer spells. There have been fluctuations of this sort in the earth’s climate since about 1.7 million years ago and they are still continuing.

We are at present some 10,000 years from the end of the last glacial period, and perhaps a little more than 20,000 years from the beginning of the next.

Each glacial period provides stimulating challenges for early humans. Islands become accessible as new territories, in some places because deep channels freeze and in others because the general drop in the level of the ocean (from water piling up on high ground as ice) results in a new land bridge.

Changes in vegetation, caused by the advancing or retreating ice caps, create new environments in which some species face extinction and others find improved opportunities.

Almost the entire span on earth of Homo erectus falls within this period of intermittent ice ages. His ability to adapt to the changing conditions must have been a large part of his success in spreading throughout the world. That adaptability is in part the result of greater thinking power. Over a span of a million years, from early African fossil skulls to those in China and Java, the braincase of Homo erectus shows on average a 25% increase in size. (Both Peking man and Java man date from about 500,000 years ago.)

This increase in intelligence no doubt leads to intermittent but important improvements in the way humans carry out the main everyday tasks on which life depends – hunting animals and gathering edible plants (see Hunter-gatherers to Farmers).

The use of fire: from more than 400,000 years ago

Homo erectus must have been much helped by his taming of fire. This has probably happened by about 500,000 years ago – the date of the so-called Peking Man, a version of Homo erectus whose traces in north China are generally believed to show evidence of the use of fire. A much earlier date, of more than a million years ago, has been claimed for burnt fragments of animal bones found in a cave at Swartkrans in South Africa.

Evidence at both these sites is disputed among scholars, but there is a consensus – from other locations in Europe and Asia – that Homo erectus is certainly using fire 400,000 years ago.

At this early stage embers are borrowed (from a volcanic source, or a fire caused by lightning) and then are carefully tended, for it is not yet possible for humans to create a flame. The use of fire for cooking greatly increases the variety of food available to humans, just as its heat in winter extends their habitat.

It is not known how much of the diet of these early people is achieved by gathering fruits and berries, or scavenging dead animals. But hunting must have contributed some part of it. Fragments have survived of sharpened wooden spears, unlikely to have been used exclusively against other men. One such point, hardened in a flame, has even been found between the ribs of an elephant.

In or out of an ice age, clothing of some kind is also a necessity for early humans living as far north of Peking. Together with speech, clothes have become almost a defining human characteristic: no animal wears any, no modern human wears absolutely none.

Unlike bones and stone tools, skin and fur do not easily survive in the ground. So it is impossible to put a date on man’s first experiments with costume. However, the bones of large animals at human sites prove that they were butchered and eaten, and stone tools were well suited to the scraping of skins. It seems inconceivable that Peking Man did not from time to time, on a cold night, wrap some simple form of fur cloak around his shoulders.

Neanderthal man: from 230,000 years ago

Around 250,000 years ago Homo erectus disappears from the fossil record, to be followed in the Middle Palaeolithic period by humans with brains which again have increased in size. They are the first to be placed within the same genus as ourselves, as (‘knowing man’).

By far the best known of them is Neanderthal man — named from the first fossil remains to be discovered, in 1856, in the Neander valley near Dusseldorf, in Germany. The scientific name of this subspecies is Homo sapiens neanderthalensis.

The Neanderthals are widely spread through Europe and the Middle East, and they thrive for an extremely long period (from about 230,000 to 35,000 years ago). Bones of animals of all sizes, up to bison and mammoth, and sophisticated stone tools are found with their remains.

Yet almost everything about them seems uncertain and controversial.

There is inconclusive evidence that the Neanderthals may have buried their dead (in one case, it has been suggested, even with flowers on the corpse). If they did have burial customs, that implies religion. Yet they have left no other trace of it.

There are skeletons of Neanderthals who lived for several years after serious injury, suggesting a social cohesion strong enough to protect the weak. But if they were so advanced socially, it seems odd to us that they should have left no art, decoration or jewellery. On the other hand a recent discovery of a Neanderthal flute surprised archaeologists, suggesting a more advanced level of culture than had been suspected.

It may be that the sense of uncertainty about Neanderthal man stems largely from our own eagerness to find early reflections of ourselves. It is perhaps only the lack of clear answers in that context which seems to blur Homo sapiens neanderthalensis.

Looked at in a different perspective, as small groups of interdependent humans subsisting in very difficult circumstances, the Neanderthals are an unprecedented success story.

Like Homo erectus before them, they seem to slip fairly suddenly out of the fossil record. About 35,000 years ago has been the conventional date for their demise, but recent finds of Neanderthal bones in Croatia suggest that they survived until 28,000 years ago. By that time they have long shared parts of the globe with anatomically modern humans.

Homo sapiens sapiens: from 90,000 years ago

The first traces of modern humans are now dated tentatively as far back as 90,000 years ago in the Middle East. In Europe, where they first appear about 35,000 years ago, they are known as Cro-Magnon from the place in the Dordogne, in France, where remains of them are first discovered in a cave in 1868.

With Cro-Magnon man there begins the sudden development of art, which seems to be one of the defining characteristics of modern man. Cro-Magnon culture provides the paintings in such famous sites as Lascaux and Altamira or the older and more recently discovered Chauvet cave.

The humans of Cro-Magnon, and their predecessors in other parts of the world, are anatomically almost identical with people today. They differ in being taller and more muscular; some of their skeletal remains reveal (contrary to modern preconceptions) a larger brain than today’s average. They are classed, with us, as Homo sapiens sapiens (‘knowing knowing man’).

The repetition does not imply doubly knowing. It is merely a method sometimes used in the Binomial system of taxonomy to identify the central species in a genus. Thus Troglodytes troglodytes is the common wren, Bufo bufo the common toad, and Homo sapiens sapiens the common man.

Before following the development of modern humans from the Upper Palaeolithic period, about 35,000 years ago (and we are at this point more than 99.999% of the way through the story so far of the universe), there is one crucial turning point which has not been charted. The creation of stone tools goes back more than 2 million years; the use of fire at least 500,000; clothing cannot be dated, but must have been adopted in colder regions not long after animals with hide or fur were first scavenged and butchered.

But what of the most distinctive human quality of all? What of speech?

Words on the brain: from 1 million years ago?

All social animals communicate with each other, from bees and ants to whales and apes, but only humans have developed a language which is more than a set of prearranged signals.

Our speech even differs in a physical way from the communication of other animals. It comes from a cortical speech centre which does not respond instinctively, but organises sound and meaning on a rational basis. This section of the brain is unique to humans.

When and how the special talent of language developed is impossible to say. But it is generally assumed that its evolution must have been a long process.

Our ancestors were probably speaking a million years ago, but with a slower delivery, a smaller vocabulary and above all a simpler grammar than we are accustomed to.

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