The Accidental Species: Misunderstandings of Human Evolution (24 page)

But human beings are not unique in their manufacture of objects that are both useful and beautiful. In fact, living things have been creating such objects for almost as long as life itself has existed. Stro
matolites—cushion-shaped domes that survive in salty lagoons—are the sculpture-like objects created by simple, single-celled cyanobacteria (blue-green algae). Around 3 billion years ago, when such creatures were the most complex forms of life on the planet, stromatolites were common and formed the first reefs. Today, reef-forming creatures such as corals (simple animals, related to sea anemones) create complex and beautiful structures, external to their own bodies.

On land, social insects create complex and well-engineered structures in which they live—one thinks of honeycombs with their regular, hexagonal cells made of wax. The towering nests of termites dwarf their creators in the same way that skyscrapers dwarf their human architects—and have air-conditioning systems to rival any created by human designers. Birds, too, make nests, some highly elaborate: think of the nests of weaverbirds, hanging from the branches of African trees, or the elaborate stages created by male bowerbirds on which they display to prospective mates. At least one bird species—the New Caledonian crow—makes and uses tools that conform to my definition of technology, modified leaves for use as probes.
⁹
Anthropologists are even beginning to recognize that apes, chimpanzees in particular, have rudimentary technologies, in which they use stones to crack nuts, or strip leaves from stalks to allow them to probe anthills. Some of these technologies even have a “cultural” dimension.
¹⁰
That is, they vary from one group of primates to another according to the learned traditions of each.

Such discoveries have led to the emerging discipline of “primate archaeology”—the excavation of occupation sites used by primates other than humans, in order to learn about the history of their technological and cultural traditions.
¹¹
This discipline is beginning to offer a much-needed comparative perspective on the relationship between technology and human history, by first admitting that technology is not unique to humans. After all, the first hominins to make tools were not humans in any sense we’d allow today. The first tools used by hominins would have been neither more nor less sophisticated than those used by modern chimpanzees. All this leads to a perhaps obvious question—why should beautiful, useful technology created by humans imply a maker any more intelligent or deliberate than (say) a crow or a weaverbird? A termite or a stromatolite? All such creatures fulfill my definition of technology in that they create things for use outside their own bodies
that allow them to do things that they might not have done unaided, irrespective of their cognitive abilities.

To reserve technology for humans requires the inclusion of such imponderables as “planning depth,” assumed to be an exclusively human attribute, which can be defined as the ability to plan for future eventualities. For example, before I can paint this wall, I shall need to open this tin of paint, but before I can do
that
, I shall need to go to my shed and find a screwdriver to use as a lever for prizing open the lid.
¹²
Should “planning depth” be included in any definition of technology? I suggest not, because the concept creates more problems than it solves. We know, for example, from behavior experiments, that some animals that use technology—notably crows—do indeed plan ahead in a way that is indistinguishable from human behavior in similar circumstances.
¹³
In which case the attribute of planning depth is not unique to humans.

For other animals, the creation of structures outside the body is presumably instinctive, that is, hardwired, rather than learned by observation—or even a completely incidental by-product of metabolism. This is probably true for all those organisms such as corals or stromatolites, which lack what we would recognize as a brain. However, this might be a distinction without a difference, because of the a priori assumption, not stated in my definition above, that brains are an absolute prerequisite for technology. But if a creature, whether or not it has a brain, modifies its environment to allow it to live where it otherwise might not, can that not be regarded as technology? Does the hidden assumption that brains are necessary prejudice one toward the view that technology is something we humans award ourselves, exclusively, because of our privileged view, and our tendency to think that we are the culmination of all organic achievement? Were the myriad polyps responsible for the Great Barrier Reef to be polled on the issue, they might with justification say that theirs is a more magnificent achievement than anything made by Man. Polyps, though, have no brains—but does it matter? Is it not easier to judge what is and what is not technology by easily observable results rather than on the motivational states of the makers, which are much harder to fathom? Because it is easier to infer motivation in fellow humans than in nonhumans, our view on technology will quite naturally be prejudiced to it being a humans-only activity—but only so long as concepts such as “planning depth” are considered as definitive.

Brains are, however, definitely required for “planning depth,”
¹⁴
whether or not this planning is applied to the manufacture of objects outside the body. However, such a concept runs into a mire of philosophical problems as eloquently discussed by Daniel Dennett in his book
Consciousness Explained
. Briefly, the idea that we imagine the world outside our heads as a dramatic performance that we are somehow observing through the windows of our senses—what philosophers call the “Cartesian theater”—is an illusion easily bruised by any number of experiments. So, whereas I might imagine a little picture of myself going to my shed to get the screwdriver I need to lever open the lid of that tin of paint I mentioned earlier, such a drama is a rationalization after the fact of a host of disparate thoughts and impulses. If there is no such thing as the Cartesian theater, there can be no such thing as planning depth. If there is no planning depth, there is no necessity to infer that brains are required for technology at all—in which case one is left with the definition of technology with which I started, which therefore must include, along with my iPad and the probes created from leaves by those clever crows from New Caledonia, the insensate creations of bees, corals, termites, and even cyanobacteria, without reference to the internal motivational states (if any) of the creators.

This problem of planning, or intention, crops up whenever we think of the hand ax, that quintessential example of Stone Age artistry. Although it’s always hard to be sure, hand axes are generally associated with a particular species of hominin,
Homo erectus
, and are examples of a toolmaking tradition or style known as “Acheulian” or “Acheulean,” after the site in France called Saint-Acheul, whence such tools were first described as such. The earliest known tools in the Acheulian style come from Kenya and are almost 1.8 million years old.
¹⁵
As
Homo erectus
spread around the Old World, hand axes went too. They have been found from Spain to China, England to Indonesia. Although some later hominins such as
Homo heidelbergensis
and Neanderthals adopted and modified the hand ax, the basic plan remained more or less the same for 1.5 million years,
¹⁶
variations dictated more by the different materials used in hand-ax manufacture rather than any change in tradition or culture.

The essentially unchanging nature of hand axes suggests that the techniques used to make them were not entirely learned or taught, but were to some extent hardwired. Even if
Homo erectus
adults taught them to their offspring, there was absolutely no conception that hand
axes could be made in anything other than the prescribed way. And if, in the sequence of steps used to make a hand ax, a blow went awry, spoiling the blank, the maker wouldn’t shrug his shoulders and make the best of a bad job, converting what might have been a hand ax into a scraper, a Large Hadron Collider, or a hi-fi cabinet. No, he would start all over again with a new blank. There are some Paleolithic sites at which hand axes have been recovered in great abundance, in various stages of manufacture. These sites are exceptional—but the exceptions still require some kind of explanation.

Perhaps most tellingly, there is much argument about what hand axes were for.
¹⁷
Although they are very beautiful,
¹⁸
they are in many ways impractical. A knife or chopper made of stone is easier to hold in the hand if some part of it retains the original, smooth stone surface—but hand axes are flaked all the way round. The raw edges of a cut flint are extremely sharp to begin with, but the edge soon dulls. So if you are going to make a chopper to smash bones or a knife to slice through flesh, it’s quicker and easier just to strike a flake and get on with it, rather than commit to the immense artistry required to make a hand ax. So what else might hand axes be for? Currency? Symbols of status? Sexual display?
¹⁹
It’s impossible to know. What we can say from the evidence is that hand axes represent the kind of stereotypical behavior associated with other examples of animal technology, such as the nests made by birds, woven with great skill but always in the same general way. Whereas it is true that some aspects of behavior that seem stereotypical are to an extent learned—birdsong is a good example—the songs of birds are always pretty much the same and characteristic of each species. The might have been true for hand axes and
Homo erectus
.

And yet
Homo erectus
looked very much more like us than any kind of bird. Is it fair to dismiss his works as the products of—for want of a better word—instinct? After all,
Homo erectus
is thought to have tamed and used fire.
²⁰
The discovery of stone tools at least a million years old on the island of Flores
²¹
shows that
Homo erectus
was capable of crossing stretches of deep ocean out of sight of land—something that might well have involved a great deal of organization and planning. Yet we know that many animals less obviously endowed with intellect can cross stretches of open ocean by accident. In
The Wisdom of Bones
, a detailed look at the life and times of
Homo erectus
, Pat Shipman and Alan Walker conclude that
Homo erectus
would have had no more spark of what we might call “humanity” than any canny social savanna pred
ator, such as a lion or a hyena. Studies on the development of
Homo erectus
teeth and skulls show that these creatures grew rapidly from infancy to adulthood, rather in the manner of apes, and lacked the extended period of growth called “childhood” during which a young modern human learns social skills from adults.
²²
To be sure, hyenas and lions teach their cubs about the ways of the world, and we might expect
Homo erectus
adults to have done the same. But that does not mean that the knowledge they imparted was any less hardwired, nor that the process of teaching and learning is not in itself stereotypical behavior.

The million-year stasis of hand axes stands in stark contrast with the technology associated with
Homo sapiens
, especially after about 45,000 years ago when the first modern humans appeared in Europe.
²³
If the technology of
Homo sapiens
can be summed up in one word, it is “change.” Modern human technology is always changing and developing as humans learn from their mistakes, never discarding errors but learning from them to improve the old or invent something entirely new. In the light of modern human technology, the technology of
Homo erectus
is not technology as we understand it today—at least not conventionally.

The shock one experiences when looking at a Stone Age cave painting or Venus figurine is that of recognition—that after millions of years of chipped pebbles and hand axes of unknown purpose, we can recognize the product of a mind that is distinctively human.

And that’s a worry, because it introduces that inescapable referential bias that plagues any study to do with human evolution—that we are both the subject and the object of study, and will naturally know (or think we know) more about ourselves, and how our minds work, than of the minds of other creatures, including extinct hominins such as
Homo erectus
. It is only us, looking backward from our perceived high estate, that look at stone artifacts and immediately assume that they must have stemmed from the same creative, artistic, practical urges that we experience ourselves. That the motivations of
Homo erectus
might have been alien to our way of thinking seems an affront until one looks at the evidence dispassionately.

Does this contrast—between the works of modern humans and those of
Homo erectus
—elevate human technology to some kind of special status? The constant change and invention that is typical of modern human technology seems to mark it out as something quite different from (say) a coral reef or a termite mound. Well, yes—and no.
The change and invention is linked with the long childhoods of modern humans, but it remains the case that human children are taught, in much the same way as the young of other animals are taught, in a stereotypical way that is determined in part by the physical constraints of brain growth and development. For example, modern humans have an innate capacity for language—any language—without being taught in any conscious way, but must also be exposed to it at a certain time in infancy for it to develop properly. And the fact that we can’t grasp the purpose of the
Homo erectus
hand ax shows that despite its protean character, human technology is not infinitely malleable. It is fundamentally limited by our capacity for understanding or conceiving what is possible, according to our senses and how our brain interprets what they are telling us. We, like
Homo erectus
, have our boundaries. To us, they seem infinitely far away, over the intellectual horizon. But who’s to say that
Homo erectus
wasn’t similarly overoptimistic about his own limitations?