42 pages • 1 hour read
Unstoppable Us, Volume 1: How Humans Took Over the World
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Chapter 1Chapter Summaries & Analyses
Chapter 1 Summary: “Humans Are Animals”
Millions of years ago, humans were among the earth’s many animals. They did not have a fixed home and gathered wild foods from trees and plants, just like other animals. Fellow animals felt no fear around humans like they do today because of this coexistence. Humans did not have tools or weapons and were weaker than other animals, like lions, from whom they might have had to flee.
Eventually, humans discovered that they could use rocks to crack open bones and extract the marrow as a food source. This discovery was the first step toward creating stone tools, and it distinguished humans from other animals. Soon, they began creating stone tools and using sticks to hunt small animals and gather wild plants. They later discovered how to create fire when they realized how to strike flint against pyrite or how to twist twigs inside of another piece of wood filled with dry leaves. Humans no longer had to wait for lightning to strike a tree to provide warmth. They could create and control fire themselves, and they began cooking food. This discovery also set humans apart from other animals, leading to evolutionary changes in the human brain and body. Consuming uncooked food was challenging, but cooked food could be eaten more quickly and was easier to digest: “As a result, humans started to change: they had smaller teeth, smaller stomachs […] and much more free time” (9). This shift also allowed human bodies to divert energy to the brain instead of the digestive process. Human brains grew larger, and people became more intelligent.
All modern humans belong to the species Homo sapiens (which Harari refers to as “Sapiens”), regardless of racial or ethnic differences. In the ancient past, however, there were a variety of human species, just as there are different species of bears or snakes today. Humans adapted to the different environmental conditions of the places they lived in and thus “gradually became more and more different—just like the bears” (13). On the small Indonesian island of Flores, for example, archeologists have found the remains of small humans whose ancestors migrated there on food when the island was connected to the mainland and became trapped when the sea water rose. Smaller humans survived on less food, and their population grew as they produced smaller and smaller children over many years. This process is called evolution, and it takes place slowly and over multiple generations. Neanderthals, another type of human, developed in Asia and Europe, where the climate was cold. Their bodies were stocky and strong, and they had large brains. Archeologists have also found the remains of a human girl in Siberia who was neither Floresian nor Neanderthal, according to DNA evidence from her finger bone. They named the group of humans to which she belonged the Denisovans, after the cave where they located her remains.
Homo sapiens means “wise humans” in Latin. Our ancestors originated in Africa. They had fire and stone tools, like other humans, but their population was small, and they lived as hunter-gatherers, not in settlements like modern humans. They began to spread throughout the globe 50,000 years ago. They gathered and hunted the Neanderthals’ food sources, condemning them to extinction. They probably also fought with different human groups at some times. Scientific evidence, however, shows that modern humans have Neanderthal DNA, so some Sapiens and Neanderthals must have interbred and produced children. Despite this genetic mixing, all types of humans except Sapiens disappeared during the expansion of the Sapiens population.
Harari asks the following: If other types of humans had continued to co-exist with us, would we be less likely to think of ourselves as special? Many modern humans believe that “we’re very special creatures. If you try to tell them that humans are animals, they often get seriously upset because they think we’re completely different from animals” (32). Perhaps Sapiens deliberately eliminated other forms of humans “to be unique” (33), but Harari next considers what enabled their ability to triumph.
Chapter 1 Analysis
Harari’s first chapter centers on the theme of Human Evolution and Adaptability, as he introduces readers to humanity’s transition from ordinary animals to extraordinarily skilled beings primed to dominate the globe. The structure of this opening chapter follows the chronological trajectory of humanity’s early development. Humans began as migratory animals, dependent on natural phenomena for survival. For instance, they needed to wait for lightning to strike a tree to provide warmth and scavenged carrion rather than hunting animals as a source of food. They were vulnerable to the elements and to attacks from other animals; it took centuries of human evolution and discoveries for humanity to learn how to dominate the natural world and populate it. Humans were not special, as creationists believe. Rather, like other animals, there were various humans who ranged in size and form, like the small Floresians and the larger, stocky Neanderthals.
Harari also uses this first chapter to introduce and explain complex scientific concepts for his young readership in order to build on these as the book progresses. Evolution is a key concept that he establishes here, and the book carefully explains the evolutionary process of humans and the divergence of multiple human species. Harari shows how the Floresians descended from people locked on an island in Asia whose bodies adapted, over the course of many generations, to the limited resources available on the island and thus grew smaller. Meanwhile, Neanderthal remains have appeared only in Europe and areas of Asia where the climate was cooler, thus explaining their stocky forms that stored heat and could withstand colder elements. The evolutionary concept of “survival of the fittest” is used to explain why some humans adapted and survived while others could not.
The opening chapter introduces Harari’s interdisciplinary approach to the reader, combining a synthesis of data from archaeology, anthropology, natural history, and genetics to tell the “meta-history” of the human story. Harari also uses his theme of Human Evolution and Adaptability to investigate how one species of humans, Homo sapiens, overtook all others, leading to the extinction of other human populations. Harari explains, using scientific evidence, that when humans discovered how to cook food using fire, their brains grew larger because their bodies spent less energy on consuming and digesting raw foods. They also had more free time to which they could devote to new discoveries. Sapiens, however, were the most intelligent of all humans, and their intellectual skills allowed them to displace other types of humans who eventually disappeared. When Sapiens spread from Africa to Europe, for example, they depleted the food sources upon which Neanderthals depended, causing the latter to become extinct. Indeed, since the book’s publication, further archeological discoveries have confirmed Harari’s theory about Sapiens’ superior skills (Slimak, Ludovic, et al. “Long Genetic and Social Isolation in Neanderthals Before Their Extinction.” Cell Genomics, 11 Sept. 2024). This has shown that one Neanderthal population lived in isolation for approximately 50,000 years, despite residing within 10 miles of other species. Scholars conclude this isolation limited opportunities for technological innovation and knowledge sharing, while the lack of genetic diversity would have presented difficulties in adjusting to climate change. In contrast, Sapiens acquired more knowledge because of their migrations.
This first chapter also introduces Harari’s argument around perceptions of human exceptionalism, both throughout history and in the present day. According to Harari, Sapiens are not inherently better than others and were not “unique” from the start. He sees this attitude as contributing to contemporary bigotry and our tendency to exploit nature without concern for the environmental and ecological consequences. His view of human evolution and our species’ position in the world contrasts directly with many traditional religions, especially Western creationism. To counter these beliefs and narratives, the book explains DNA evidence that shows how Sapiens and Neanderthals bred and are not solely descended from a single human species. Harari holds that humanity’s global dominance resulted from centuries of evolutionary developments that gave humans advantages that our ancestors leveraged to survive. In fact, Sapiens, as Harari explains, were weaker than Neanderthals; they likewise needed more food than the Floresians, and they were less adapted to cold environments than the ancient Denisovans, another early human group whose remains archeologists located in Siberia. It was only after centuries of evolution and development and after all other species of humans disappeared that Sapiens were established as unique from other animals. Harari questions why Sapiens overcame others to survive into the modern era. The scientific name, Homo sapiens—“wise humans”—provides a clue, he argues, although he also suggests that this naming is characteristic of humanity’s tendency for self-regard and exceptionalism. Human Evolution and Adaptability were undoubtedly important to priming Sapiens to dominate the globe, but further, related developments were also essential, as the next chapter shows.
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