The Book of Humans by Adam Rutherford [Book Summary – Review]

Humans are exceptional bouquets. Cognitively, human brains can do amazing things. The level of sophistication is crazy in human language. Unsurprisingly, we have come to see animals as just nature’s creatures.

However, humanity’s uniqueness is a peripheral issue. As brought to light below, our features which are the same as those of animals do not overshadow what makes us different from each other.

This tumultuous journey into the history of evolution can alter how you view yourself and your spot on the Earth, as it is filled with many affairs from the world of animals. What follows is a pleasing summary of the way of animal evolution packed with innovations in genetics, scientists’ findings, and artifacts unearthed through excavations.    

Just a caution: Things about animal sexuality are told explicitly in Chapter 4. 

In the following chapters, you are going to acquire knowledge of these:

  • How crows prepare their babies for life;
  • The fact that Homo sapiens is not the single species that does the farming on our planet; and  
  • Characteristics of a certain salutation of bonobos (note: it isn’t appropriate for people under 17).

Chapter 1 – Animals utilize devices. However, humans use way more developed instruments.

What qualities make you a human being? Your ability to talk to your friend on the phone in a sophisticated language? Manufacturing and using a computer? Or that you can do what the rest of the animals can’t – creating works of art and discussing them?

Although we were created by the common evolutionary process as animals, we enjoy seeing our species as masters of Animalia. They enter sexual intercourse in the same way as we do. They form interconnected social groups and institutions as well. They utilize devices like a human in more than a few manners. Homo sapiens is not as exceptional as we assert, even though we detest it outright.

Still, humans are exceptional too. We are the most advanced and complicated of all species in terms of cognitive abilities, language, and culture. Being both an animal and exceptional compared to other animals is a creational contradiction in homo sapiens.

An instrument is an object that is not a natural part of an animal being but is utilized to expand its capacity. This can be an adjusted device, a discovered object, or an artificially produced machine. We use hair clips to hold our hair in place. For mathematical purposes, we use computers as machines.

Scientists long argued that no animal other than Homo sapiens could utilize tools. Today, we are aware of the fact that this is wrong.

For instance, thin rods are chimpanzees’ devices for catching termites. While Orangutans use sticks for fishing in streams, gorillas utilize them to understand if the water is shallow enough to pass.

Although tools are used to a fascinating extent in Animalia, the absence of this utilization in 99 percent of species indicates that its commonness is not high. To put it another way, technology is comparably infrequent. Additionally, the sophistication of human technologies exceeds those of other animals. One of the reasons for this is that many other members of Animalia have smaller brains than human brains. Another reason is that other animals are not as skillful as humans. Even though it has a developed neocortex, it is not possible to see a dolphin making a violin. Unfortunately, its flippers are not agile compared to our fingers.

However, despite their flippers, we have many things to learn from dolphins and their ingenious utilization of devices. We are going to discover this in Chapter 2. 

Chapter 2 – Among the members of Animalia, quite a few obtain abilities via cultural and biological transfer simultaneously.

You have utilized tools your entire lifetime if you are a human being, which you presumably are. You have written with a pencil. You have drunk water from a glass. However, have you utilized a creature as if it is an apparatus before? Bottlenose dolphins in Shark Bay, Australia, habitually do this. Utilizing tools inventively, this animal embeds its rostrum into a sea sponge to dig at the rugged sea bottom to find food. This sea sponge, functioning like a kind of nose cover, safeguards a dolphin’s rostrum against cracks and itchy corners where it forages for something to eat (utilization of an animal by another animal to devour the other).

Yet how bottlenose dolphins use sea sponges is not the whole thing. In what ways they become competent in it is also equally pivotal. The usage of sea sponges is an ability to be acquired later for dolphins since it is not a genetic quality. To be more particular, it is a thing to be learned from a parent. Scientists call this operation cultural transmission.

Other than humans, cultural transmission has only been seen in birds, monkeys, and dolphins up to now. Shall we take a glance at an instance? In a 2013 research in Seattle, Washington, scientists conditioned some crows to identify a face mask as friendly and a second one as menacing. After five years, the scientists came close to these crows, occasionally with the friendly mask, occasionally with the menacing one. How these crows reacted was fascinating: While they went away from the menacing mask, they disregarded the friendly one. The crows recalled.

However, this is not the striking point. The really impressive part is that the crows that are new to the community (namely, chicks that had hatched over the years) gave the same reaction. To put it in another way, they seemingly learned how adults of the community understood how much danger human faces posed. Similar to human nannies teaching kids to construct sentences, or dolphin parents instructing their young to utilize sea sponges, crows did not transmit the ability to recognize faces in a hereditary way, but in a social way.

We do not imply that DNA did not determine anything. Experts usually speak of learned abilities as if they were not connected with biology in one way or another. However, biology and culture are substantially interweaved when it comes to the evolutionary process. The existence of an ability encoded in DNA is a prerequisite for the acquisition of culturally transmitted ideas and abilities. For instance, farmers need their brains to know which seeds will sprout out just as they need their hands to plow the earth although farming is not something genetically encoded practice.

Chapter 3 – Cultivation gave rise to our modern society. Yet, Homo sapiens is not the only farmer on the Earth.

If you are not oblivious to what happens in the outside world, you know about the paleo diet, which urges us to follow the diet of our ancestors, at least a certain amount of people believe that such a nutrition habit ever existed.

Advocates of this diet, controversially,  argue that agriculture ruined our digestion. They are not alone in criticizing the cultivation of plants. Numerous experts have asserted that the doom of egalitarian society step by step was a result of the initiation of agriculture. Nevertheless, our current modern society would not be present if there was no cultivation. In substance, all things (digital music services, books, museums, computer and console games, etc.) you may be fond of living in a civilized society emerged thanks to the settled life on a territory.

It is not easy to exaggerate agriculture’s importance in the evolutionary process of Homo sapiens. This power is so effective that it has altered us genetically. Our inability to perform the skill of milk processing for thousands of years is the conventional instance of this. Approximately in 5000 BC, soon afterward we started livestock farming, and and some changes happened. Human DNA mutated in such a way that enabled them to consume milk even after adolescence. Consider this. We built up the skill of processing milk as soon as we acquired the utilization of milking animals. Although dealing with agriculture and husbandry has been transmitted via cultural transmission, today the skill of consuming the products of these practices is in our DNA.

However, it becomes apparent that Homo sapiens is not the only farmer. In reality, we are comparably latecomers in this practice. Leaf-cutter ants have been farming for 60 million years, compared to our 12,000 years of career in agriculture. You have presumably seen these creatures on TV, carrying ripped pieces of leaves. Although many people think they are food for the ants, they are not. Leaf-cutter ants use leaves as fertilizer for a kind of fungus, which is pivotal for their lives, they grow in their formicaries.

While this method is intricate, ants growing merely one type of fungus is no match for humans cultivating an amazing diversity of plants. At this point, the fact that humans are both animals and much more than that, the stress at the core of our being, becomes apparent to us.

In Chapter 4, you are going to learn in what ways such a contradiction comes to an end in a quite distinct world of animals.

Chapter 4 – There are other creatures than humans that have separated sex from reproduction.

Humans perform it either on the top of tables or in bed, with company or apart from others. They engage in it during the early hours of the day or after nightfall, by leaning on bodies of trees or sandy seashores. Occasionally, we have it with our loved ones. From time to time, we have it with our detested ones.

Yeah, what you thought is right: A relation that we display striking eagerness for, namely, sex. We have every kind of sex ranging from mating to masturbation and we do them with pleasure. Actually, in terms of sex, the only action we avoid doing is just to produce children.

There is no doubt that humans need to have sex for the continuation of the bloodline of Homo sapiens. However, an assessment argues that out of a thousand sexual intercourses that can lead to the birth of a new offspring, merely one achieves this. Here, this only covers sexual organ contact in the heterosexual sense. This rate would be doubly uneven if we took into account all remaining types of sex, such as oral sex, anal sex, and bondage. Even though sex is a necessity for our biology, the evident development of our relationship with it has surpassed that.

In this respect, Homo sapiens is not solo. Almost all bees and birds do this without breeding purposes. For instance, in the living world, cunnilingus is almost everywhere; likewise masturbating. Ranging from bats to elephants, giraffes to lions, Animalia teems with same-sex relationships. In bonobos, females massage their external sexual organs mutually almost every 120 minutes!

Saying that amusement is the reason for these sexual behaviors sounds fair, but we have not yet completely known their causes. However, Rutherford put forward that experts are not willing to accept this hypothesis. Delight cannot be evaluated through science, nor can we ask animals other than humans if they are taking pleasure from that entire sexual intercourse. It is not easy for the majority of scientists to accept the notion that animals other than humans exhibit specific acts simply because they are joyful. In preference to this, they look at possible evolutionary goals of sexual relations without aims for breeding. The apparent instance of this in Homo sapiens would be sexual intercourse as a mode of social interaction with others.

Barring a very small number of exclusions, most sexual behaviors in Animalia are not for an obvious aim of evolution. Adam Rutherford asserts that maybe the only thing that scientists need is to be warm to the likelihood that desire for delight is the impetus for sex.

Chapter 5 – DNA is the principal impetus of biological evolution.

Similar. Not distinct in type but in level. No matter how you wish to say it, this should already be obvious: While we have a lot of common features with other animals, some qualities distinguish us from them. If you ask any high school student who has self-esteem the reason for this, they can give you an explicit response. The evolution from common primal living beings is the cause of our similarities. Our differences stem from the distinct evolutionary lines.

Yet what is the precise meaning of this? How did that avail? 

Being a molecule, DNA operates as a sort of biological precept booklet, informing living creatures on the ways of development, growth, operation, and procreation. It performs this via genes, the sequences of nucleotides in DNA that code for corporeal characteristics. Should characteristics expand a living being’s skill of continuation, nature shall select the DNA that secures them, and transmit it to future descendants. Contrary to this, should the characteristics disrupt the continuity of the living being’s life, they shall be discarded little by little.

Every creature on our planet shares a great deal of our human genes. These genes, which have existed for millions of years, are prone to code for fundamental pieces of human biochemistry. Lesser amount of the genes are common to humans and nonhuman animals. Every mammal and humans share even fewer genes. Humans and the rest of the Hominidae still share a few of them. DNA goes through slight alterations in time via mutating incidentally. These can be considered as genetic versions of erratum, an orthographic mistake that goes unnoticed due to the poor arrangement of copies by the proteins that carry out this business. Alterations in human DNA and the evolution of various kinds of creatures happen via such mutations.

Cardinal improvements have enabled us to achieve considerable development in perceiving how our primitive ancestors became the creatures they are now. For instance, what is currently known is that a small piece of DNA makes our hands skillful, a feature that is essential to enable us to utilize complex instruments. It is known that when human toes became short enough to enable them to walk on two legs, and when their flesh and bones gained the physical skill of getting a language. On the upshot, humans have plenty of knowledge about how their species evolved to be characteristically what they are. They acquired every single piece of that information through examination of the remarkable molecule DNA that codes for each living being on our planet.  

Chapter 6 – Our linguistic properties create differences between us and nonhuman animals.

The way by which we can comprehend these words is exceedingly sophisticated. The naked truth that humans manage to put words together in a manner that others can grasp is a striking original ingenuity of our species.

Sophisticated design of mental and physical biology is at the center of this. This is the way we can produce a large order of sounds that is essential for our language. Such a design contains an extremely well-rounded and animate tongue that reaches a strong larynx by passing through the sophisticatedly concave hyoid bone. There is a linkage between the larynx and the nose and the nose has a connection to various other face muscles. Thanks to the advanced-level control mechanism of the central nervous system, all these devices can be used as one wishes. On our planet, no other member of the Animalia has such a complex biological foundation for linguistic skills.

Surely, Homo sapiens is not the single animal that can make sounds. Woof is of dogs. Meow is of cats. Many animals vocally speak to each other. Several birds, for instance, are among the animals that have the skill to gain language similar to humans, by imitating the voices of other animals. Nevertheless, singing some songs all these birds can do with that skill. Conversely, in our human world, there are more than 6,000 different spoken languages which are in a continuous evolution. In Animalia, the brain of Homo sapiens is the sole brain that can obtain language. In Animalia, solely humans have the skill of using sophisticated grammar and syntax and solely they are in the possession of myriads of words.

The words are ideograms. Because we know the shape of an ear thanks to our experiences, when we see an ear, we understand that it is an ear. Whenever we read the word ear, we know the word’s meaning, even though we do not see an actual ear. The reason for this is that we possess the skill of comprehending the meaning’s symbolic units. To repeat, this skill is not possessed solely by us. For instance, prairie dogs have distinct antipredator calls for various beasts. Resembling our language and being a format of vocal symbolism, each call is based on the skill of making two things equivalent to each other, in this occasion, a particular call for a particular beast. 

However, their calls are primordial in comparison with human speech. For the present, only Homo sapiens have proper language. Plus, language is a necessary condition for behavioral modernity, which enabled humans to develop into what they are now.  

Chapter 7 – Reasoning, imagining, and skill of producing artworks point out behavioral modernity of Homo sapiens.

We are not quite different from people who lived in Africa 200,000 years ago in terms of physical appearance. If we cut their hair and dressed them in clothes that suit today’s fashion, they would not look strange in the cafe where we live. They would be able to perform the physical skill of talking just like us. In any case, the thing they would not have yet would be the language.

Forming a language took a while for humans afterwards their body acquired the speaking skill. Approximately 130,000 years. Humanity’s culture altered in that epoch, not its DNA. The language was not the final thing that altered. Throughout the years, ranging from the skill of comprehending words to the skill of producing artworks, human understanding of symbols widened more and more.

Roughly 400,000 years ago, our species completely attained behavioral modernity. At that time, Homo sapiens turned into what it is now. At that time, the cavern walls began to fill with images, and humans began to make manikins. At that time, humans began to make ornamental jewelry, and they began to make wood and ivory sculptures of outlandish beasts. Art and craft products from those times, including prehistoric flutes made of swan bones, now fill the Earth from Asia to Europe.

Löwenmensch (Lion Man), a chimera made from the tusk of a hairy mammoth is one of the most well-known of these products. Lion Man is a remarkable artwork that demonstrates skillfulness and excellent control of the nervous system and also reveals the calculation in choosing the proper bone and planning in forming the object. This artifact puts forth a perception of nature, and most prominently, the skill for fantasizing about an unreal entity, a dreamed-up half-man and half-cave lion beast. In a nutshell, Löwenmensch is a work of complex intelligence.

However, there are older examples of descriptive art. In 2018, an array of cave images in the north of Spain were identified as 64,000 years old, dating back to the time when humans in Europe were a species other than Homo sapiens. The meaning of this? The relative of Homo sapiens, Homo neanderthalensis, was creating artworks about 20,000 years earlier we occupied Europe. Several skills we think are original to us end up being common with another kind of human.           

The Book of Humans: A Brief History of Culture, Sex, War and the Evolution of Us by Adam Rutherford Book Review

In his renowned monologue, Hamlet fittingly described humans as “the paragon of animals.” Humans and other creatures have a mutual fundamental biological design, and becoming human is a result of the same evolutionary mechanisms. Still, both our highly developed linguistic skills and intricate culture make us different from others by making us absolutely animal and exceptional at the same time.

Take into account your correlation.

When you feel lonely and estranged in the future, keep in mind that you are bonded to all living things on our planet via evolution, genes, social practices, and sexual relations. Because you are Homo sapiens, you possess the emotional and analytical competence to think that you are not completely disengaged from the larger world of living beings.       

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