This post has been migrated from medium.com/@injulkarnilesh.

This is one of those books which will change your perspective about almost everything; after reading this book you will not look at people around you and at yourself the same way.

The book describes history of “us” in terms of three revolutions

1. Cognitive Revolution

2. Agricultural Revolution

3. Scientific Revolution

In this post, let’s cover the first.

Evolution

First thing first. We are homo sapiens, belonging to species “Sapiens” (means wise) of genus “Homo”. We are not the only humans, though we are the only living humans now. There had been many before and during our existence.

It’s a common fallacy to envision these species as arranged in a straight line of descent, with Ergaster begetting Erectus, Erectus begetting the Neanderthals, and the Neanderthals evolving into us.

Many of us believe that there were only one type of humans living on the Earth at a given time; one types of humans lead to another; as earlier ones disappearing the new ones appeared. But between 2 million ago until around 10,000 years ago the Earth was inhabited by multiple human species. We lived along with Neanderthals and (scholars are in dilemma about) Homo Erectus.

We evolved in east Africa when Neanderthals were busy living in European area.

Simplified version of how we evolved from monkeys is this :

Just 6 million years ago, a single female ape had two daughters. One became the ancestor of all chimpanzees, the other is our own grandmother.

Today we human beings are very important on the planet Earth but we were not always; we were just another species surviving.

The archaic humans loved, played, formed close friendships and competed for status and power — but so did chimpanzees, baboons and elephants. There was nothing special about them.

Top of the food chain

With natural abilities, humans (including other homo species) were around middle of the food chain pyramid. We were hunters as well as prey.

Since around 400,000 years ago humans started hunting big games and in last 100,000 years only we have reached to the top. This was a very short time considering millions of years of evolution. Animals, those were at the top of food chain, had reached there over very long period of time within which other animals had chances to evolve to be be able to save themselves.

Humankind ascended to the top so quickly that the ecosystem was not given time to adjust.

There were many factors which enabled humans to reach the top. Most important were brain size and our ability to cooperate on larger scale.

With fire we not only started to save ourselves from bigger animals by scaring them away but also to cook food which made a big difference. As we started to eat cooked food :

1. We started to eat different types of foods which we otherwise could not digest.

2. We had huge variety of diet with that.

3. We could make do with smaller teeth and shorter intestines.

4. As brains and intestines are largest consumers of bodily energy, some scholars believe that with our shorter intestines we had more energy for our brains and that allowed Neanderthals and Sapiens to have larger brains.

Brothers

As we know that we Sapiens co-existed with other humans, the question then is what happened to them (our brothers)?

There are two theories about it :

Interbreeding theory

This theory believes that when the Sapiens crossed paths with Neanderthals and Homo Erectus while migrating out of east Africa they bred with them. So the species got intermingled resulting in current human beings. With this theory then Eurasians are mixture of Sapiens and Neanderthals, while east asians are mixture of Sapiens and Erectus.

This theory is not widely accepted for both political and scientific reasons. As this theory says current humans are in fact different races, it gives power to the racism. Scientifically also it is quite not possible to, so successfully, breed different species to produce fertile offsprings.

Replacement theory

This theory believes that different humans species had different anatomies and most likely different mating habits; and proposes Neanderthal genes dies out with them when they were killed off by Sapiens. We replaced other human species wherever we went.

This theory says that we all have same genetics and racial difference between us is negligible. This theory is not only politically right but also has stronger archeological evidences, and is more accepted.

When results of 4 years of study of Neanderthal genome were declared in 2010 and further compared with our genome, geneticists found out that 1-4 percent of unique human DNA of modern population in Middle East and Europe is Neanderthal DNA. After some months when DNA was extracted from fossilised finger from Denisova and compared with DNA of modern Melanesians and Aboriginal Australians, upto 6 percent was found to be similar.

This gives a strong position to interbreeding theory, but the matching numbers are not high enough to prove its totality.

Since Neanderthals and Denisovans contributed only a small amount of DNA to our present-day genome, it is impossible to speak of a ‘merger’ between Sapiens and other human species. Although differences between them were not large enough to completely prevent fertile intercourse, they were sufficient to make such contacts very rare.

Well, biological reality is not black and white, there are also important grey areas.

If we go, until further research proves otherwise, with replacement theory; we have interesting question as to how we were able to outlive stronger humans like Neanderthals?

Imaginary Realities

Though Sapiens had already populated East Africa 150,000 years ago, we began to overrun the rest of the planet and drive other human species to extinction only about 70,000 years ago.

In the first recorded encounter between Sapiens and Neanderthals, the Neanderthals won. About 100,000 years ago, some Sapien groups migrated north to the Levant, which was Neanderthal territory, but failed to secure a firm footing. But then, beginning about 70,000 years ago, Homo Sapiens started doing very special things.

So, What changed? What did we do? Well, it all changed when we started to cooperate on very large scale as a result of revolution in Sapiens’ cognitive abilities.

The most commonly believed theory argues that accidental genetic mutations changed the inner wiring of our brain, enabling us to think in unprecedented ways and to communicate using an altogether new type of language. It was nothing but a random mutation by a random chance. Other species had their languages, but ours was amazingly supple. We can connect a limited number of sounds and signs to produce an infinite number of sentences, each with distinct meaning.

Eg. A monkey can let know her band of a lion she saw with her moments and voices. But a Sapian could tell exactly where did she saw the lion, like, near by that river where the lion was hunting a bison. Then the Sapien band can discuss what they should do whether to stay away from river or go there to chase away the lion and hunt the bison.

Other theories believe that with such a language we were importantly able to talk about each other, to gossip; which made us more social.

Most important effect of such a language was that it enabled Sapiens to talk of non existing, imaginary things; and that made a huge difference, because with such a shared myths we could cooperate on a very large scale.This ability to create an imagined reality out of words enabled large numbers of strangers to cooperate effectively.

If we consider single Homo Sapien vs single Neanderthal or single lion per se; we don’t stand a chance. Yeah, you can use gun, clever you! But you can not have that gun of your own, alone. For that you would need to extract metal from mines, forge it into gun and bullets, invent gunpowder, teach yourself shooting and all. You can fight though with any animal on face of the earth if you cooperate with other human beings. And that is what happened.

Chimpanzees or other human species could also work, live together but there was a limit as to how big the band could be. 150 is max size of the band, for other species, that can cooperate; when it grows beyond that it falls apart. It is not the case with us, we can cooperate on a very large scale because we have common, shared myths and imaginations like gods, nations, money etc. that holds us together.

There are no gods in the universe, no nations, no money, no human rights, no laws, and no justice outside the common imagination of human beings.

The fiction has enabled us not merely to imagine things, but to do so collectively.

We could fight off Neanderthals because we could form bigger bands which could fought smaller bands of Neanderthals.

Unlike lying, an imagined reality is something that everyone believes in, and as long as this communal belief persists, the imagined reality exerts force in the world.

Male chimps cannot gather in a constitutional assembly to abolish the office of alpha male and declare that from here on out all chimps are to be treated as equals. Such dramatic changes in behaviour would occur only if something changed in the chimpanzees’ DNA. Not the case with us. We could incorporate such a change relatively really fast without need of genetic change because we could imagine something like democracy. Ever since the Cognitive Revolution, Sapiens have been able to change their behaviour quickly, transmitting new behaviours to future generations, through the help of myths and stories, without any need of genetic or environmental change. The real difference between us and chimpanzees is the mythical glue that binds together large numbers of individuals, families and groups. This glue has made us the masters of creation.

Just try to imagine how difficult it would have been to create states, or churches, or legal systems if we could speak only about things that really exist, such as rivers, trees and lions.

With non existing gods we could create larger bands sharing imaginary common myths. With non existing rules, constitutions we could create nations. This imaginations, rules have no natural existence beyond our minds. If you jump, you fall back on earth, that is natural law; if you murder somebody you should get punished is not natural but a man made law; and such laws enables us to live together.

Modern example of such a myth is corporate organizations. Thousands of employees, homo sapiens cooperate under an imginary unit called Apple Inc.

Ever since the Cognitive Revolution, Sapiens has thus been living in a dual reality. On the one hand, the objective reality of rivers, trees and lions; and on the other hand, the imagined reality of gods, nations and corporations. As time went by, the imagined reality became ever more powerful, so that today the very survival of rivers, trees and lions depends on the grace of imagined entities such as gods, nations and corporations.

Ecological serial killers

With great power come great responsibility.

The Sapiens in Indonesia, descendants of apes who lived on the African savannah, became Pacific seafarers without growing flippers and without having to wait for their noses to migrate to the top of their heads as whales did. Instead, they built boats and learned how to steer them. And these skills enabled them to reach and settle Australia.

As we reached there we started destroying rich flora and fauna of the region. More than 90% of megafauna disappeared with arrival of Sapiens around 45,000 years ago, which had survived even the ice age. This mass extinction followed that of American region when we reached there. These were not coincidences, we were responsible for extinction of various species for forests we burnt and animals we hunted. We even drove huge mammoths to extinction by hunting them for meal and their skins for our clothing. This was mainly possible because they did not get a chance to adapt to save themselves from our tools and because of their slow reproduction cycles.

If we combine the mass extinctions in Australia and America, and add the smaller-scale extinctions that took place as Homo sapiens spread over Afro-Asia — such as the extinction of all other human species — and the extinctions that occurred when ancient foragers settled remote islands such as Cuba, the inevitable conclusion is that the first wave of Sapiens colonisation was one of the biggest and swiftest ecological disasters to befall the animal kingdom.

If we knew how many species we’ve already eradicated, we might be more motivated to protect those that still survive.

The wandering bands of storytelling Sapiens were the most important and most destructive force the animal kingdom had ever produced.