The Book of Humans by Adam Rutherford

Looks like a history book to me, and it should, because it says that on the cover: “A brief history of culture, sex war, and evolution of us”. Okay.

Peter Frankopan, author of The Silk Roads, has called it “Charming, compelling” – I liked that book, even though I have not written about it on Sunchaser but an endorsement from Mr. Frankopan does make me think this is going to be a nice read.

I often approach books on history with little bit of trepidation, not because there are not a lot of lessons to learn from history. In fact, it is to the contrary.

So it’s not the dearth of lessons that makes me wary of history books, but rather, the style of writing of history books is characteristically in the form of a story – and extracting lessons from stories is always an exercise in subjective evaluation. So often I’ll be left debating whether that is what the author really meant or if they meant anything at all.

I suppose I should get better at it with the practice but you’ll have to deal with my limitations for now.

I’d like to apologise in advance for my approach to this book which, like for any other book I read, is going to be concerned with implications for the here and now rather than recounting history.

Let’s see how this goes.

The author is going to chart our history as a species and how we became the one dominating the planet.

At the same time they will also take us off the pedestal and show the things that we think are uniquely human are, in fact, not. We’re all friends here: “… all life on Earth is related by common ancestry, and that includes us.“.

The book will help us:

1. make sense of our own behaviour
2. chart the evolution of human technology
3. how sex for pleasure isn’t just a human characteristics
4. how the animal world too has its share of mindless violence
5. why modern behaviour evolved the way it did (so linked to the first point).

“‘Am I special?’ Paradoxically, the answer turned out to be both no and yes.“.

The fact that we use tools and technology is why we are categorise ourselves as “homo” and the rest of the living world as something else – “… presence of tools represents the boundary between the genus Homo and what came before, meaning that humans are actually defined by tool use.“.

Technology that we’ve created ourselves using our big brains. Our brains pretty smart but it’d be a mistake to think they come out on top on every parameter – the author gives a few examples.

How we got these big brains is complicated and there is a lot of luck involved too.

Our hands are special too, allowing us dexterity that no other animal, even the other great apes, can achieve.

And finally, our minds, the ability to conceive of ourselves are separate from the other, to develop an ego, to develop complex emotions beyond the primal ones allowed us use the brain and the hand to a definite end.

Now, there are a few others who use tools like us but they’re not very many (<1% of species) – Orangutans, Gorillas will use sticks ward of enemies and to test depth before crossing a river, use leaves as gloves when handling spiky fruit. Dolphins will use sponges as protection from sea urchins while hunting them. Caledonian crows will use sticks to wheedle out grubs from rotting tree bark. Australian kites will pick up burning sticks from one place and drop them on dry grass somewhere else to get the small animals living in them to scamper out.

These examples may be fascinating but no other animal comes close – “… co-evolution of minds, brains and hands that drove us to use sticks, knap stones, refine those flakes, and eventually, after long periods of stasis, develop our technological prowess so that we could carve statues, and musical instruments, and weapons that made resources ever-more available.“.

Every living thing fights, for its own survival, for survival of its progeny.

But war, which is a premeditated, prolonged, often armed conflict – that is unique to humans.

The author talks about how one troop of chimpanzees will sometimes engage in prolonged conflict with another troop and seem to engage and kill its members in a measured and strategic manner.

This seems an adaptive strategy borne out of lowering resources and increasing population density in a troop’s territory.

To chalk up our proclivity for war to evolution would be a mistake because apart from chimps we do not see any other living being doing this.

Indeed, our close cousins bonobos will resolve conflict by literally having sex.

Farming

We discovered/invented farming about 10000-12000 years ago and the rest is history. But we’re not the only ones that farm because leaf cutter ants exist.

Fashion

We humans love our fashion but we’re not the only ones decorating ourselves, Majoidea crabs stick stuff on their shells, the assassin bug “carries a backpack made of the carcasses of its prey“.

We’re a species obsessed with sex, and the author posits that we’re not necessarily having so much sex (166667 heterosexual encounters each minutes, globally) to have babies because only 1 in 1000 of those encounters results in one, (“can we truly say that sex in human is for procreation?“).

There may be truth in that statement but I’d say just because a lot of sex is wasted in creating a baby does not mean having babies is the not the primary (albeit subconscious) reason – just like a a drug has only a 0.01% chance in eliminating a patient’s stage IV metastatic cancer does not mean that the reason for taking that drug is anything other than cancer treatment.

Nevertheless, look around you, there are a lot more humans than have ever been, and we’ve achieved that primarily through our improved ability to keep people living longer.

Which means that unlike the past where a couple would need to plan for several children and see only a few survive to adulthood, we do not have to do this any more.

Yet our obsession with sex continues, this is interesting to explore – “our interest in sex has clearly evolved well beyond any basic animal instinct.“.

The author then goes on to point how many animals, fish, birds, reptiles, fungi engage in all sorts of interesting and weird sex that can result in offspring but also sex that cannot result in offspring (masturbation, its own category, is also discussed) – giving credence to the idea that besides us there are so many other living organisms that engage in sex for pleasure.

Which brings us to the point that besides having babies, sex also leads to better social bonding – critical for keeping a group together.

There is also a lesser point that some organisms may just be blindly following their instincts when they have sex, particularly in cases like necrophilia.

It should be clear though that sex for babies is not the only reason – neither in us nor in the others.

But to try and go too deep into why our sexual preferences or behaviour evolved the way it did, whether it has a connection with other organisms and whether all of it has some sort of predictive power into our “essential” nature would be a mistake – behaviours, rituals, practices, culture are influenced by genes and environment but not determined by them and instead by the “inscrutable interactions between biology and experience.“.

Sometimes, things happen just because.

Because at some point during our evolution a baby ape was born where two chromosomes sort of stuck together (the number 2 chromosome in humans) and instead of meeting a swift and unceremonious end, “this ape got lucky“, ever since then we’ve had 23 chromosomes.

The author shares a few other examples like the NOTCH2NL and SRGAP2 genes that play roles in brain development and are unique to us (but to say that it was because of these that we became humans would be oversimplification), the HACNS enhancer that allows us to have dextrous hands but decidedly less so feet – something uniquely human, .

But if we’re being honest about it, there isn’t much difference between us and other organisms in terms of the underlying code (we share 80% of our DNA with mice), rather the difference emerges in how that parts of that code have been uniquely adapted to interact with the environment and with each other.

We have language, birds have it too. But the way we have taken language to a whole new level is unique – the number of languages we speak, the grammar in each, how they’ve evolved and borrowed from each other over time.

Art is unique to us (at least by its complexity) and the author gives several examples how humans were creating art tens of thousands of years ago like the Lion Man, Venus of Hohle Fels, El Castillo cave paintings, Gorham’s Cave, Blombos Cave, caves at Pinnacle Point and many more.

There is evidence to indicate that some animals may possess a rudimentary sense of ego, self conception, and the ability to conceive of others as conscious beings as evidenced by other members of the great ape family passing the mirror test.

But this pales in comparison to the complexity and sophistication of the self awareness and awareness of others mind that we possess. We have been highly conscious beings for a very long time now – for at least 20,000 years (though most likely for much longer) we humans have possessed a sophisticated sense of self.

We are able to understand that others are also complex conscious beings and are able to make sense of what they are thinking, bye, understanding, facial expressions, body, language, behaviour, voice, clues, and so on – not unlike reading someone’s mind. Indeed, such is our proclivity towards seeing agency that we will imagine it when none actually exists (like how a house whose wooden flooring creaks in the cool night as a result the wood shrinking could be imagined as some sort of ghost that roam the halls in the dark).

We can make massive leaps forward and backward in time and once we have made those leaps, we can also place ourselves in the mind of a person from that time and imagine/feel what they would.

Not only are we aware of others, we are also aware of ourselves, very much so. We can place ourselves and feel ourselves as a distinct being in this grand universe we find ourselves in.

Perhaps the biggest difference is captured by the author in the last chapter “Many animals learn. Only humans teach.” – Indeed, what you are reading right now is an endeavour in the same direction.

Homo sapiens is a curious animal, he has an unquenchable thirst for knowledge and in trying to acquire that knowledge he also ends up teaching his fellows, in fact in his true self he likes it when he shares his learning with others.

• … all life is evolved. But that doesn’t necessarily mean that all behaviours are explained with the central idea of evolution …
• Evolution is blind, mutation is random, selection is not.
• Error and trial is a conservative process; radical biological change normally results in death.
• All abilities are evolved, which doesn’t mean that they all have common roots.
• Biology enables culture, culture changes biology.
• Some behaviours are encoded in DNA and others are acquired, yet still built on top of a genetic and physiological frame that allows the development of that trait.
• Our reasons for going to war are difficult to justify by evolutionary theory, and this is reinforced by the fact that only chimpanzees seem to emulate a scale of conflict that could be described as anything like warfare.
• Agriculture changed humankind irreversibly and set the foundations for the current era.
• To dismiss how we dress or wear our hair as trivial and insignificant or of no value is daft.

• What is clear among all this murk is that we, Homo sapiens, are the last surviving humans, and with no plausible prospect of us diverging into new, sexually incompatible populations, we will be the last humans.
• We spend a titanic amount of time, effort and resources on trying to touch other people’s genitals.
• … almost all humans that can masturbate, do.
• … some aspects of sex are not designed solely to impregnate the female, but to simply prevent another male from becoming the father.
• It is inviting to apply human interpretations to animal behaviour, and it is similarly tempting to suggest that the presence of these non-reproductive sexual acts in us relates to our evolutionary origins. But the evidence is not compelling.
• Homosexuality therefore is a sexual identity independent of the evolutionary imperative to reproduce.
• Nature is not cruel, it is simply indifferent,
• With the exception of onomatopoeia, linguists generally think that the symbolism in words is arbitrary.

• There are plenty of traces of modern skills and behaviour long before the so-called ‘cognitive revolution’ 45,000 years ago. But they are sporadic blips in time, and not permanent …
• The full package came about because of how we organised our society … [we see] loss of cultural sophistication in societies whose populations do not grow, migrate or are cut off from a bigger populace.
• Larger populations enable the transfer of complex cultural skills with far greater efficiency than smaller ones.
• Where we stand apart most significantly is in cultural accumulation and transmission. Many animals learn. Only humans teach.
• Life is continuous on Earth, endless forms most beautiful. We force discrete classifications upon that continuum to help us make sense of a planet bursting with life through eons. You sit somewhere on that trajectory, unique in trying to figure out your place in all of this.

Entertaining and easy read.

Many sections with interesting factoids but no lessons, like there is a whole chapter on the idiosyncratic sex life of insects, fungi, spiders, fish, birds which definitely make for a fun read but not for very many takeaways except that “evolution had did what it had to do”.

The first half of the book the author just talks about how we’re not too different from all these animals we call, deridingly, animals.

In the second half he talks about how we’re unique from all other animals but pretty soon you realise that our uniqueness is not because of some fundamental difference between us and them but rather how we’ve used the same fundamental building blocks to incredible sophisticated ends while other animals have not.

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Aviral Prakash