The deadliest species on earth almost never appears on wildlife shows featuring ferocious animals. We love watching the bloody exploits of apex predators like sharks and tigers, but we might enjoy these shows a bit less if they starred our own species. Yet this would accurately reflect the role of humans in the earth’s ecosystem. However dangerous large carnivores might seem, their destructive prowess pales in comparison to the havoc Homo sapiens routinely wreak.
We are the subject of an ambitious and illuminating new book by the Israeli historian Yuval Noah Harari. Sapiens: A Brief History of Humankind tells the wonderful and terrifying saga of the human species on earth, from our prehistory as hunter-gatherers to our present as technical wizards and hopeful colonizers of new planets. The story begins roughly 70,000 years ago with what archaeologists call the Cognitive Revolution. Because boats, oil lamps, bows and arrows, needles, and the earliest art began appearing between 70,000 and 30,000 years ago, scholars reason that genetic mutations linked to greater intelligence began spreading through the genomes of our ancestors during these years.
This is the first of many revolutions that structure the book. Next is the Agricultural Revolution, the process beginning around 10,000 BC that led to a population explosion, a gradual shift to life in villages, more specialization in human professions, and eventually the rise of governments, writing systems, and other tools for social organization. These developments might seem unambiguously positive, but Harari sees the invention of agriculture as a decidedly mixed blessing.
Abandoning our nomadic lifestyle allowed humans to have children more frequently, and this created an incentive to increase agricultural yields by working more fields for longer hours. The more food we grew, the more kids we could have, and as we had more kids, we had to grow more food. But the quality of our diets decreased as we switched from the rich diversity of hunter-gatherer fare to the monolithic consumption of a few staple crops. Harari blames the sudden crowding together of humans and animals in dense settlements for spikes in infectious diseases. Not only did we humans work more hours for less nutritious substance, but it seems that we also got sick more often.
We were already a deadly species when we became farmers and herders. From Australia to the Americas, our ancestors eradicated many local animal populations as they spread across the globe. Because the large animals on these landmasses had not co-evolved with humans, they lacked an adaptive fear response and became easy prey for human hunters.
But our lethal powers vastly increased after The Scientific Revolution, the first stirrings of which Harari places around 1500 BC. In one of the book’s most interesting chapters, he links the Renaissance voyages of European explorers to the birth of modern science. The physical acquisition of new territories was both motive and metaphor for the intellectual conquest of new knowledge. Explorers needed precise instruments to navigate the long voyage across the Atlantic, but they also had to make sense of a dazzling range of new plants, peoples, and environments once they arrived. Such demands created whole new fields of scientific inquiry.
These expeditions had deadly consequences for the indigenous peoples of Africa, the Americas, and later Southeast Asia. They also laid the foundations of modern capitalism. Limited liability companies – LLCs – formed initially as joint investment instruments to mitigate the considerable risks of a transatlantic voyage. If many people owned stock in a company, a few vanished vessels were unlikely to bankrupt any particular individual. And as the trips began to establish profitable trade networks, more people wanted to invest in the joint-stock companies. Soon a positive feedback loop took hold: Exploration made money, and this money funded increasingly rapacious exploration.
The Industrial Revolution further enhanced the productivity and deadliness of Homo sapiens. Factories exploited new energy sources – both human and natural – and flooded regional and eventually global markets with an unprecedented number of consumer goods. Among the byproducts: pollution, poverty, and the extinction of countless species of flora and fauna.
One of Harari’s major points is that the forces that allowed humans to spread across the globe did not necessarily make us happier. Our species has grown from scattered bands of nomads into a ubiquitous presence that weighs down nearly every corner of the globe.
Our future remains to be written. We could extinguish ourselves voluntarily (perhaps by uploading brains to computers with collective consciousness) or accidentally (through global warming, nuclear war, or some other catastrophe). – remains to be seen.
But if we do survive, the next 70,000 years will make an amazing sequel to Harari's book.