Darwin's Unfinished Symphony

How Culture Made the Human Mind

Kevin N. Lala

• Publisher: Princeton University Press
• Year: 2018
• ISBN:
  9780691184470
• Topic: Biological Sciences
• Subtopic: Evolution
• Index: Biological Sciences

Humans possess an extraordinary capacity for culture, from the arts and language to science and technology. But how did the human mind—and the uniquely human ability to devise and transmit culture—evolve from its roots in animal behavior? Darwin's Unfinished Symphony presents a captivating new theory of human cognitive evolution. This compelling and accessible book reveals how culture is not just the magnificent end product of an evolutionary process that produced a species unlike all others—it is also the key driving force behind that process. Kevin N. Lala tells the story of the painstaking fieldwork, the key experiments, the false leads, and the stunning scientific breakthroughs that led to this new understanding of how culture transformed human evolution. It is the story of how Darwin's intellectual descendants picked up where he left off and took up the challenge of providing a scientific account of the evolution of the human mind.

PART I

FOUNDATIONS OF CULTURE

CHAPTER 1

DARWIN’S UNFINISHED SYMPHONY

It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and so dependent upon each other in so complex a manner, have all been produced by laws acting around us.… Thus from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows.

—CHARLES DARWIN, ON THE ORIGIN OF SPECIES

As he looked out on the English countryside from his study at Down House, Charles Darwin could reflect with satisfaction that he had gained a compelling understanding of the processes through which the complex fabric of the natural world had come into existence. In the final, perhaps the most famous, and certainly the most evocative, passage of The Origin of Species, Darwin contemplated an entangled bank, replete with plants, birds, insects, and worms, all functioning with intricate coherence. The tremendous legacy of Darwin is that so much of that interwoven majesty can now be explained through the process of evolution by natural selection.

I look out of my window and see the skyline of St Andrews, a small town in southeastern Scotland. I see bushes, trees, and birds too, but the view is dominated by stone buildings, roofs, chimneys, and a church steeple. I see telegraph poles and electricity pylons. I look south, and in the distance is a school, and just to the west, a hospital fed by roads dotted with busy commuters. I wonder, can evolutionary biology explain the existence of chimneys, cars, and electricity in as convincing a fashion as it does the natural world? Can it describe the origin of prayer books and church choirs, as it does the origin of species? Is there an evolutionary explanation for the computer on which I type, for the satellites in the sky, or for the scientific concept of gravity?

At first sight, such questions may not appear particularly troubling. Clearly human beings have evolved, and we happen to be unusually intelligent primates that are good at science and technology. Darwin claimed, “the most exalted higher animals” had emerged “from the war of nature,”¹ and our own species is surely as high and exalted as species come. Isn’t it apparent that our intelligence, our culture, and our language are what has allowed us to dominate and transform the planet so dramatically?

With a little more thought, however, this type of explanation unravels with disturbing rapidity, in the process generating a barrage of even more challenging questions. If intelligence, language, or the ability to construct elaborate artifacts evolved in humans because they enhance the ability to survive and reproduce, then why didn’t other species acquire these capabilities? Why haven’t other apes, our closest relatives, who are genetically similar to us, built rockets and space stations and put themselves on the moon? Animals have traditions for eating specific foods, or singing the local song, which researchers call “animal cultures,” but these possess no laws, morals, or institutions, and are not imbued with symbolism, like human culture. Nor do animal tool-using traditions constantly ratchet up in complexity and diversity over time as our technology does. There seems a world of difference between a male chaffinch’s song and Giacomo Puccini’s arias, between fishing for ants by chimpanzees and haute cuisine restaurants, or between the ability of animals to count to three and Isaac Newton’s derivation of calculus. A gap, an ostensibly unbridgeable gap, exists between the cognitive capabilities and achievements of humanity and those of other animals.

This book explores the origins of the entangled bank of human culture, and the animal roots of the human mind. It presents an account of the most challenging and mysterious aspect of the human story, an explanation for how evolutionary processes resulted in a species so entirely different from all others. It relates how our ancestors made the journey from apes scavenging a living on ants, tubers, and nuts, to modern humans able compose symphonies, recite poetry, perform ballet, and design particle accelerators. Yet Rachmaninoff’s piano concertos did not evolve by the laws of natural selection, and space stations didn’t emerge through the “famine and death” of the Darwinian struggle. The men and women who design and build computers and iPhones have no more children than those in other professions.

So, what laws account for the relentless progress and diversification of technology, or the changing fashions of the arts? Explanations based on cultural evolution,² whereby competition between cultural traits generates changes in behavior and technology,³ can only begin to be considered satisfactory with clarification of how minds capable of generating complex culture evolved in the first place. Yet, as later chapters in this book reveal, our species’ most cherished intellectual faculties were themselves fashioned in a whirlpool of coevolutionary feedbacks in which culture played a vital role. Indeed, my central argument is that no single prime mover is responsible for the evolution of the human mind. Instead, I highlight the significance of accelerating cycles of evolutionary feedback, whereby an interwoven complex of cultural processes to reinforce each other in an irresistible runaway dynamic that engineered the mind’s breathtaking computational power.

Comprehending the distinguishing features of humanity through comparison with similar characteristics in other animals is another central theme in this book, and a distinctive feature of my research group’s approach to investigating human cognition and culture. Such comparisons not only help to put our species’ achievements in perspective, but help us to reconstruct the evolutionary pathways to humanity’s spectacular achievements. We not only seek a scientific explanation for the origins of technology, science, language, and the arts, but endeavor to trace the roots of these phenomena right back to the realm of animal behavior.

Consider, for illustration, the school that I see from my window. How could it have come into existence? To most people the answer to this question is trivial; that is, workers from a building company contracted by the Fife Council built it. Yet to an evolutionary biologist the construction represents an enormous challenge. The immediate mechanical explanation is not the problem; rather, the dilemma is to understand how humans are even capable of such undertakings. With a little training, the same people could build a shopping mall, bridge, canal, or dock, but no bird ever built anything other than a nest or bower, and no termite worker deviated from constructing a mound.

When one starts to reflect, the scale of cooperation necessary to build a school is astounding. Imagine all of the workers who had to coordinate their actions in the right place at the right time to ensure that foundations are safely laid, windows and doors are put in place, piping and electricity wires are suitably positioned, and woodwork is painted. Imagine the companies with whom the contractor had to engineer transactions, buy the building materials, arrange for delivery, purchase or loan the tools, subcontract jobs, and organize finances. Think of the businesses that had to make the tools, nuts, bolts, screws, washers, paint, and windowpanes. Imagine the people who designed the tools; smelted the iron; logged the trees; and made the paper, ink, and plastic. So it goes on, endlessly, in a voracious multidimensional expansion. All of those interactions, that endless web of exchanges, transactions, and cooperative endeavors—the vast majority carried out by unrelated individuals on the basis of promises of future remuneration—had to function for the school to be built. Not only did these cooperative transactions work, but they repeatedly operate with seamless efficiency day in and day out, as new schools, hospitals, shopping malls, and leisure centers are put together all across the country and around the world. Such procedures are so commonplace that we now entirely take it for granted that the school will be built, and even complain if completion is a little late.

I earn my living in part by studying animals, and I am captivated with the complexity of their social behavior. Chimpanzees, dolphins, elephants, crows, and countless other animals, exhibit rich and sophisticated cognition that reveals an often impressive level of intelligence that through the process of natural selection has become suited to the worlds they each inhabit. Yet if we ever wanted a lesson in what an achievement of creativity, cooperation, and communication the construction of a building is, we only have to give a group of animals the materials, tools, and equipment to build such a structure, and then see what happens. I would imagine the chimpanzees might grasp pipes or stones to throw or wave about in dominance displays. The dolphins might plausibly play with materials that floated. Corvids or parrots would perhaps pick out some novel items with which to decorate their nests. I do not wish to disparage the abilities of other animals, whose achievements are striking in their own domains. Yet science has accrued a strong understanding of the evolution of animal behavior, while the origins of human cognition and the complexities of our society, technology, and culture remain poorly understood. For most of us in the industrialized world, every aspect of our lives is utterly reliant on thousands of cooperative interactions with millions of individuals from hundreds of countries, the vast majority of whom we never see, don’t know, and indeed never knew existed. Just how exceptional such intricate coordination is remains hard to appreciate; nothing remotely like it is found in any of the other 5–40 million species on the planet.⁴

The inner workings of the school and the activities of children and staff are just as astonishing to an evolutionary biologist like myself. There is no compelling evidence that other apes will go out of their way to teach their friends or relatives anything at all, let alone build elaborate institutions that dispense vast amounts of knowledge, skills, and values to hordes of children with factory-like efficiency. Teaching, by which I mean actively setting out to educate another individual, is rare in nature.⁵ Nonhuman animals assist one another in alternative ways, such as provisioning with food or collaborating in an alliance, but they mostly aid their offspring or close relatives, who share their genes and hence also possess their tendency to help.⁶ Yet in our species, dedicated teachers devote vast amounts of time and effort with children entirely unrelated to them, helping them to acquire knowledge, in spite of the fact that this does not inherently increase a teacher’s evolutionary fitness. Pointing out that teachers are paid, which might be regarded as a form of trade (i.e., goods for work), only trivializes this mystery. The pound coin or dollar bill have no intrinsic value, the money in our bank account has a largely virtual existence, and the banking system is an unfathomably complex institution. Explaining how money or financial markets came into existence is no easier than explaining why schoolteachers will coach unrelated pupils.

As I gaze at the school, I imagine the children sitting at their desks, all dressed in the same uniform, and all (or, at least, many) sitting calmly and listening to their teacher’s instruction. But why do they listen? Why bother absorb facts about events in antiquity, or labor to compute the angle of an abstract shape? Other animals only learn what is of immediate use to them. Capuchin monkeys don’t instruct juveniles in how their ancestors cracked nuts hundreds of years ago, and no songbird educates the young about what is sung in the wood across the road.

Just as curious to a biologist is the fact that the pupils all dress the same. Some of these children will come from less fortunate backgrounds. Their parents cannot easily afford to spend money on special clothes for school. When they finish their education many of these young people will exchange school attire for another uniform (probably equally uncomfortable), perhaps comprising a suit, or the white and blue attire of doctors and nurses in the hospital down the road. Even the students at my university, replete with liberal, radical, and freethinking values often dress the same, in jeans, T-shirts, sweatshirts, and sneakers. Where did these proclivities come from? Other animals don’t have fashions or norms.

Darwin provided a compelling explanation for the protracted history of the biological world, but only hinted about origins of the cultural realm. When discussing evolution of the “intellectual faculties,” he confessed: “Undoubtedly it would have been very interesting to have traced the development of each separate faculty from the state in which it exists in the lower animals to that in which it exists in man; but neither my ability nor knowledge permit the attempt.”⁷ With the benefit of hindsight, we should not be surprised if Darwin struggled to understand the origins of humanity’s intellectual achievements; it is a monumental challenge. A satisfactory explanation demands insight into the evolutionary origins of some of our most striking attributes—our intelligence, language, cooperation, teaching, and morality—yet most of these features are not just distinctive, they are unique to our species. That makes it harder to glean clues to the distant history of our minds through comparison with other species.

At the heart of this challenge lies the undeniable fact that we humans are an amazingly successful species. Our range is unprecedented; we have colonized virtually every terrestrial habitat on Earth, from steaming rainforests to frozen tundra, in numbers that far exceed what would be typical for another mammal of our size.⁸ We exhibit behavioral diversity that is unparalleled in the animal kingdom,⁹ but (unlike most other animals) this variation is not explained by underlying genetic diversity, which is in fact atypically low.¹⁰ We have resolved countless ecological, social, and technological challenges, from splitting the atom, to irrigating the deserts, to sequencing genomes. Humanity so dominates the planet that, through a combination of habitat destruction and competition, we are driving countless other species to extinction. With rare exceptions, the species comparably prosperous to humans are solely our domesticates, such as cattle or dogs; our commensals, such as mice, rats, and house flies; and ...