Homo Deus: a brief History of Tomorrow

PART I
Homo sapiens Conquers the World
What is the difference between humans and all other animals?
How did our species conquer the world?
Is Homo sapiens a superior life form, or just the local bully?

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2
The Anthropocene
With regard to other animals, humans have long since become gods. We don’t
like to reflect on this too deeply, because we have not been particularly just or
merciful gods. If you watch the National Geographic channel, go to a Disney film
or  read  a  book  of  fairy  tales,  you  might  easily  get  the  impression  that  planet
Earth is populated mainly by lions, wolves and tigers who are an equal match for
us  humans.  Simba  the  lion  king  holds  sway  over  the  forest  animals;  Little  Red
Riding Hood tries to evade the Big Bad Wolf; and little Mowgli bravely confronts
Shere  Khan  the  tiger.  But  in  reality,  they  are  no  longer  there.  Our  televisions,
books,  fantasies  and  nightmares  are  still  full  of  them,  but  the  Simbas,  Shere
Khans  and  Big  Bad  Wolves  of  our  planet  are  disappearing.  The  world  is
populated mainly by humans and their domesticated animals.
How  many  wolves  live  today  in  Germany,  the  land  of  the  Grimm  brothers,
Little Red Riding Hood and the Big Bad Wolf? Less than a hundred. (And even
these  are  mostly  Polish  wolves  that  stole  over  the  border  in  recent  years.)  In
contrast,  Germany  is  home  to  5  million  domesticated  dogs.  Altogether  about
200,000  wild  wolves  still  roam  the  earth,  but  there  are  more  than  400  million
domesticated dogs.
1
 The  world  contains  40,000  lions  compared  to  600  million
house  cats;  900,000  African  buffalo  versus  1.5  billion  domesticated  cows;  50
million  penguins  and  20  billion  chickens.
2
 Since  1970,  despite  growing
ecological  awareness,  wildlife  populations  have  halved  (not  that  they  were
prospering in 1970).
3
In 1980 there were 2 billion wild birds in Europe. In 2009
only 1.6 billion were left. In the same year, Europeans raised 1.9 billion chickens
for meat and eggs.
4
At present, more than 90 per cent of the large animals of the
world  (i.e.  those  weighing  more  than  a  few  kilograms)  are  either  humans  or
domesticated animals.
Scientists divide the history of our planet into epochs such as the Pleistocene,
the  Pliocene  and  the  Miocene.  Officially,  we  live  in  the  Holocene  epoch.  Yet  it
may be better to call the last 70,000 years the Anthropocene epoch: the epoch
of humanity. For during these millennia Homo sapiens became the single most

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important agent of change in the global ecology.
5
This is an unprecedented phenomenon. Since the appearance of life, about 4
billion years ago, never has a single species changed the global ecology all by
itself.  Though  there  had  been  no  lack  of  ecological  revolutions  and  mass-
extinction events, these were not caused by the actions of a particular lizard, bat
or  fungus.  Rather,  they  were  caused  by  the  workings  of  mighty  natural  forces
such  as  climate  change,  tectonic  plate  movement,  volcanic  eruptions  and
asteroid collisions.
Pie chart of global biomass of large animals.
Some  people  fear  that  today  we  are  again  in  mortal  danger  of  massive
volcanic eruptions or colliding asteroids. Hollywood producers make billions out
of these anxieties. Yet in reality, the danger is slim. Mass extinctions occur once
every  many  millions  of  years.  Yes,  a  big  asteroid  will  probably  hit  our  planet
sometime  in  the  next  100  million  years,  but  it  is  very  unlikely  to  happen  next
Tuesday. Instead of fearing asteroids, we should fear ourselves.
For  Homo  sapiens  has  rewritten  the  rules  of  the  game.  This  single  ape
species  has  managed  within  70,000  years  to  change  the  global  ecosystem  in
radical and unprecedented ways. Our impact is already on a par with that of ice
ages and tectonic movements. Within a century, our impact may surpass that of
the asteroid that killed off the dinosaurs 65 million years ago.
That  asteroid  changed  the  trajectory  of  terrestrial  evolution,  but  not  its
fundamental rules, which have remained fixed since the appearance of the first
organisms 4 billion years ago. During all those aeons, whether you were a virus
or  a  dinosaur,  you  evolved  according  to  the  unchanging  principles  of  natural
selection. In addition, no matter what strange and bizarre shapes life adopted, it
remained confined to the organic realm – whether a cactus or a whale, you were
made  of  organic  compounds.  Now  humankind  is  poised  to  replace  natural

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selection  with  intelligent  design,  and  to  extend  life  from  the  organic  realm  into
the inorganic.
Even if we leave aside these future prospects and only look back on the last
70,000  years,  it  is  evident  that  the  Anthropocene  has  altered  the  world  in
unprecedented  ways.  Asteroids,  plate  tectonics  and  climate  change  may  have
impacted organisms all over the globe, but their influence differed from one area
to  another.  The  planet  never  constituted  a  single  ecosystem;  rather,  it  was  a
collection  of  many  loosely  connected  ecosystems.  When  tectonic  movements
joined North America with South America it led to the extinction of most South
American marsupials, but had no detrimental effect on the Australian kangaroo.
When the last ice age reached its peak 20,000 years ago, jellyfish in the Persian
Gulf and jellyfish in Tokyo Bay both had to adapt to the new climate. Yet since
there  was  no  connection  between  the  two  populations,  each  reacted  in  a
different way, evolving in distinct directions.
In  contrast,  Sapiens  broke  the  barriers  that  had  separated  the  globe  into
independent ecological zones. In the Anthropocene, the planet became for the
first  time  a  single  ecological  unit.  Australia,  Europe  and  America  continued  to
have  different  climates  and  topographies,  yet  humans  caused  organisms  from
throughout the world to mingle on a regular basis, irrespective of distance and
geography. What began as a trickle of wooden boats has turned into a torrent of
aeroplanes, oil tankers and giant cargo ships that criss-cross every ocean and
bind every island and continent. Consequently the ecology of, say, Australia can
no longer be understood without taking into account the European mammals or
American microorganisms that flood its shores and deserts. Sheep, wheat, rats
and  flu  viruses  that  humans  brought  to  Australia  during  the  last  300  years  are
today far more important to its ecology than the native kangaroos and koalas.
But  the  Anthropocene  isn’t  a  novel  phenomenon  of  the  last  few  centuries.
Already tens of thousands of years ago, when our Stone Age ancestors spread
from  East  Africa  to  the  four  corners  of  the  earth,  they  changed  the  flora  and
fauna  of  every  continent  and  island  on  which  they  settled.  They  drove  to
extinction  all  the  other  human  species  of  the  world,  90  per  cent  of  the  large
animals of Australia, 75 per cent of the large mammals of America and about 50
per cent of all the large land mammals of the planet – and all before they planted
the first wheat field, shaped the first metal tool, wrote the first text or struck the
first coin.
6
Large  animals  were  the  main  victims  because  they  were  relatively  few,  and
they bred slowly. Compare, for example, mammoths (which became extinct) to
rabbits  (which  survived).  A  troop  of  mammoths  numbered  no  more  than  a  few
dozen individuals, and bred  at  a  rate  of  perhaps  just  two  youngsters  per  year.

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Hence if the local human tribe hunted just three mammoths a year, it would have
been  enough  for  deaths  to  outstrip  births,  and  within  a  few  generations  the
mammoths disappeared. Rabbits, in contrast, bred like rabbits. Even if humans
hunted  hundreds  of  rabbits  each  year,  it  was  not  enough  to  drive  them  to
extinction.
Not  that  our  ancestors  planned  on  wiping  out  the  mammoths;  they  were
simply  unaware  of  the  consequences  of  their  actions.  The  extinction  of  the
mammoths  and  other  large  animals  may  have  been  swift  on  an  evolutionary
timescale,  but  slow  and  gradual  in  human  terms.  People  lived  no  more  than
seventy  or  eighty  years,  whereas  the  extinction  process  took  centuries.  The
ancient  Sapiens  probably  failed  to  notice  any  connection  between  the  annual
mammoth  hunt  –  in  which  no  more  than  two  or  three  mammoths  were  killed  –
and  the  disappearance  of  these  furry  giants.  At  most,  a  nostalgic  elder  might
have told sceptical youngsters that ‘when I was young, mammoths were much
more plentiful than these days. And so were mastodons and giant elks. And, of
course, the tribal chiefs were honest, and children respected their elders.’
The Serpent’s Children
Anthropological  and  archaeological  evidence  indicates  that  archaic  hunter-
gatherers were probably animists: they believed that there was no essential gap
separating humans from other animals. The world – i.e. the local valley and the
surrounding  mountain  chains  –  belonged  to  all  its  inhabitants,  and  everyone
followed  a  common  set  of  rules.  These  rules  involved  ceaseless  negotiation
between all concerned beings. People talked with animals, trees and stones, as
well  as  with  fairies,  demons  and  ghosts.  Out  of  this  web  of  communications
emerged  the  values  and  norms  that  were  binding  on  humans,  elephants,  oak
trees and wraiths alike.
7
The  animist  world  view  still  guides  some  hunter-gatherer  communities  that
have survived into the modern age. One of them is the Nayaka people, who live
in  the  tropical  forests  of  south  India.  The  anthropologist  Danny  Naveh,  who
studied the Nayaka for several years, reports that when a Nayaka walking in the
jungle encounters a dangerous animal such as a tiger, snake or elephant, he or
she might address the animal and say: ‘You live in the forest. I too live here in
the forest. You came here to eat, and I too came here to gather roots and tubers.
I didn’t come to hurt you.’
A Nayaka was once killed by a male elephant they called ‘the elephant who
always  walks  alone’.  The  Nayakas  refused  to  help  officials  from  the  Indian

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forestry  department  capture  him.  They  explained  to  Naveh  that  this  elephant
used to be very close to another male elephant, with whom he always roamed.
One day the forestry department captured the second elephant, and since then
‘the  elephant  who  always  walks  alone’  had  become  angry  and  violent.  ‘How
would  you  have  felt  if  your  spouse  had  been  taken  away  from  you?  This  is
exactly  how  this  elephant  felt.  These  two  elephants  sometimes  separated  at
night,  each  walking  its  own  path  .  .  .  but  in  the  morning  they  always  came
together  again.  On  that  day,  the  elephant  saw  his  buddy  falling,  lying  down.  If
two are always together and then you shoot one – how would the other feel?’
8
Such an animistic attitude strikes many industrialised people as alien. Most of
us  automatically  see  animals  as  essentially  different  and  inferior.  This  is
because even our most ancient traditions were created thousands of years after
the end of the hunter-gatherer era. The Old Testament, for example, was written
down in the first millennium
BC
, and its oldest stories reflect the realities of the
second  millennium
BC
.  But  in  the  Middle  East  the  age  of  the  hunter-gatherers
ended  more  than  7,000  years  earlier.  It  is  hardly  surprising,  therefore,  that  the
Bible  rejects  animistic  beliefs  and  its  only  animistic  story  appears  right  at  the
beginning, as a dire warning. The Bible is a long book, bursting with miracles,
wonders and marvels. Yet the only time an animal initiates a conversation with a
human is when the serpent tempts Eve to eat the forbidden fruit of knowledge
(Bil’am’s donkey also speaks a few words, but she is merely conveying to Bil’am
a message from God).
In the Garden of Eden, Adam and Eve lived as foragers. The expulsion from
Eden  bears  a  striking  resemblance  to  the  Agricultural  Revolution.  Instead  of
allowing Adam to keep gathering wild fruits, an angry God condemns him ‘to eat
bread by the sweat of your brow’. It might be no coincidence, then, that biblical
animals  spoke  with  humans  only  in  the  pre-agricultural  era  of  Eden.  What
lessons  does  the  Bible  draw  from  the  episode?  That  you  shouldn’t  listen  to
snakes, and it is generally best to avoid talking with animals and plants. It leads
to nothing but disaster.
Yet the biblical story has deeper and more ancient layers of meaning. In most
Semitic  languages,  ‘Eve’  means  ‘snake’  or  even  ‘female  snake’.  The  name  of
our ancestral biblical mother hides an archaic animist myth, according to which
snakes are not our enemies, but our ancestors.
9
Many animist cultures believed
that humans descended from animals, including from snakes and other reptiles.
Most  Australian  Aborigines  believed  that  the  Rainbow  Serpent  created  the
world.  The  Aranda  and  Dieri  people  maintained  that  their  particular  tribes
originated  from  primordial  lizards  or  snakes,  which  were  transformed  into
humans.
10
 In  fact,  modern  Westerners  too  think  that  they  have  evolved  from

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reptiles. The brain of each and every one of us is built around a reptilian core,
and the structure of our bodies is essentially that of modified reptiles.
Paradise lost (the Sistine Chapel). The serpent – who sports a human upper body – initiates the entire
chain of events. While the first two chapters of Genesis are dominated by divine monologues (‘and God
said . . . and God said . . . and God said . . .’), in the third chapter we finally get a dialogue – between Eve
and the serpent (‘and the serpent said unto the woman . . . and the woman said unto the serpent . . .’). This
unique conversation between a human and an animal leads to the fall of humanity and our expulsion from
Eden.
Detail from Michelangelo Buonarroti (1475–1564), the Sistine Chapel, Vatican City © Lessing Images.
The authors of the book of Genesis may have preserved a remnant of archaic
animist  beliefs  in  Eve’s  name,  but  they  took  great  care  to  conceal  all  other
traces.  Genesis  says  that,  instead  of  descending  from  snakes,  humans  were
divinely  created  from  inanimate  matter.  The  snake  is  not  our  progenitor:  he
seduces us to rebel against our heavenly Father. While animists saw humans as
just another kind of animal, the Bible argues that humans are a unique creation,
and any attempt to acknowledge the animal within us denies God’s power and
authority.  Indeed,  when  modern  humans  discovered  that  they  actually  evolved
from reptiles, they rebelled against God and stopped listening to Him – or even
believing in His existence.
Ancestral Needs
The  Bible,  along  with  its  belief  in  human  distinctiveness,  was  one  of  the  by-
products of the Agricultural Revolution, which initiated a new phase in human–
animal  relations.  The  advent  of  farming  produced  new  waves  of  mass
extinctions, but more importantly, it created a completely new life form on earth:

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domesticated animals. Initially this development was of minor importance, since
humans  managed  to  domesticate  fewer  than  twenty  species  of  mammals  and
birds, compared to the countless thousands of species that remained ‘wild’. Yet
with the passing of the centuries, this novel life form became dominant. Today
more than 90 per cent of all large animals are domesticated.
Alas, domesticated species paid for their unparalleled collective success with
unprecedented  individual  suffering.  Although  the  animal  kingdom  has  known
many types of pain and misery for millions of years, the Agricultural Revolution
generated completely new kinds of suffering, that only became worse over time.
To the casual observer domesticated animals may seem much better off than
their  wild  cousins  and  ancestors.  Wild  boars  spend  their  days  searching  for
food,  water  and  shelter,  and  are  constantly  threatened  by  lions,  parasites  and
floods. Domesticated pigs, in contrast, enjoy food, water and shelter provided by
humans, who also treat their diseases and protect them against predators and
natural  disasters.  True,  most  pigs  sooner  or  later  find  themselves  in  the
slaughterhouse.  Yet  does  that  make  their  fate  any  worse  than  the  fate  of  wild
boars?  Is  it  better  to  be  devoured  by  a  lion  than  slaughtered  by  a  man?  Are
crocodile teeth less deadly than steel blades?
What  makes  the  fate  of  domesticated  farm  animals  particularly  harsh  is  not
just  the  way  they  die,  but  above  all  the  way  they  live.  Two  competing  factors
have  shaped  the  living  conditions  of  farm  animals  from  ancient  times  to  the
present day: human desires and animal needs. Thus humans raise pigs in order
to get meat, but if they want a steady supply of meat, they must ensure the long-
term  survival  and  reproduction  of  the  pigs.  Theoretically  this  should  have
protected  the  animals  from  extreme  forms  of  cruelty.  If  a  farmer  did  not  take
good  care  of  his  pigs,  they  would  soon  die  without  offspring  and  the  farmer
would starve.
Unfortunately,  humans  can  cause  tremendous  suffering  to  farm  animals  in
various  ways,  even  while  ensuring  their  survival  and  reproduction.  The  root  of
the  problem  is  that  domesticated  animals  have  inherited  from  their  wild
ancestors  many  physical,  emotional  and  social  needs  that  are  redundant  on
human  farms.  Farmers  routinely  ignore  these  needs,  without  paying  any
economic penalty. They lock animals in tiny cages, mutilate their horns and tails,
separate  mothers  from  offspring  and  selectively  breed  monstrosities.  The
animals suffer greatly, yet they live on and multiply.
Doesn’t  that  contradict  the  most  basic  principles  of  natural  selection?  The
theory of evolution maintains that all instincts, drives and emotions have evolved
in  the  sole  interest  of  survival  and  reproduction.  If  so,  doesn’t  the  continuous
reproduction of farm animals prove that all their real needs are met? How can a

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pig have a ‘need’ that is not really needed for his survival and reproduction?
It  is  certainly  true  that  all  instincts,  drives  and  emotions  evolved  in  order  to
meet  the  evolutionary  pressures  of  survival  and  reproduction.  However,  if  and
when  these  pressures  suddenly  disappear,  the  instincts,  drives  and  emotions
they had shaped do not disappear with them. At least not instantly. Even if they
are no longer instrumental for survival and reproduction, these instincts, drives
and  emotions  continue  to  mould  the  subjective  experiences  of  the  animal.  For
animals  and  humans  alike,  agriculture  changed  selection  pressures  almost
overnight,  but  it  did  not  change  their  physical,  emotional  and  social  drives.  Of
course evolution never stands still, and it has continued to modify humans and
animals in the 12,000 years since the advent of farming. For example, humans
in Europe and western Asia evolved the ability to digest cows’ milk, while cows
lost  their  fear  of  humans,  and  today  produce  far  more  milk  than  their  wild
ancestors. Yet these are superficial alterations. The deep sensory and emotional
structures  of  cows,  pigs  and  humans  alike  haven’t  changed  much  since  the
Stone Age.
Why  do  modern  humans  love  sweets  so  much?  Not  because  in  the  early
twenty-first  century  we  must  gorge  on  ice  cream  and  chocolate  in  order  to
survive.  Rather,  it  is  because  when  our  Stone  Age  ancestors  came  across
sweet fruit or honey, the most sensible thing to do was to eat as much of it as
quickly as possible. Why do young men drive recklessly, get involved in violent
arguments  and  hack  confidential  Internet  sites?  Because  they  are  following
ancient  genetic  decrees  that  might  be  useless  and  even  counterproductive
today, but that made good evolutionary sense 70,000 years ago. A young hunter
who risked his life chasing a mammoth outshone all his competitors and won the
hand of the local beauty; and we are now stuck with his macho genes.
11
Exactly the same evolutionary logic shapes the lives of pigs, sows and piglets
in human-controlled farms. In order to survive and reproduce in the wild, ancient
boars  needed  to  roam  vast  territories,  familiarise  themselves  with  their
environment  and  beware  of  traps  and  predators.  They  further  needed  to
communicate  and  cooperate  with  their  fellow  boars,  forming  complex  groups
dominated  by  old  and  experienced  matriarchs.  Evolutionary  pressures
consequently made wild boars – and even more so wild sows – highly intelligent
social animals, characterised by a lively curiosity and strong urges to socialise,
play, wander about and explore their surroundings. A sow born with some rare
mutation  that  made  her  indifferent  to  her  environment  and  to  other  boars  was
unlikely to survive or reproduce.
The  descendants  of  wild  boars  –  domesticated  pigs  –  inherited  their
intelligence,  curiosity  and  social  skills.
12
 Like  wild  boars,  domesticated  pigs

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communicate  using  a  rich  variety  of  vocal  and  olfactory  signals:  mother  sows
recognise  the  unique  squeaks  of  their  piglets,  whereas  two-day-old  piglets
already  differentiate  their  mother’s  calls  from  those  of  other  sows.
13
 Professor
Stanley  Curtis  of  the  Pennsylvania  State  University  trained  two  pigs  –  named
Hamlet and Omelette – to control a special joystick with their snouts, and found
that  the  pigs  soon  rivalled  primates  in  learning  and  playing  simple  computer
games.
14
Today  most  sows  in  industrial  farms  don’t  play  computer  games.  They  are
locked  by  their  human  masters  in  tiny  gestation  crates,  usually  measuring  two
metres  by  sixty  centimetres.  The  crates  have  a  concrete  floor  and  metal  bars,
and hardly allow the pregnant sows even to turn around or sleep on their side,
never mind walk. After three and a half months in such conditions, the sows are
moved  to  slightly  wider  crates,  where  they  give  birth  and  nurse  their  piglets.
Whereas  piglets  would  naturally  suckle  for  ten  to  twenty  weeks,  in  industrial
farms  they  are  forcibly  weaned  within  two  to  four  weeks,  separated  from  their
mother and shipped to be fattened and slaughtered. The mother is immediately
impregnated again, and sent back to the gestation crate to start another cycle.
The  typical  sow  would  go  through  five  to  ten  such  cycles  before  being
slaughtered herself. In recent years the use of crates has been restricted in the
European Union and some US states, but the crates are still commonly used in
many  other  countries,  and  tens  of  millions  of  breeding  sows  pass  almost  their
entire lives in them.
The human farmers take care of everything the sow needs in order to survive
and  reproduce.  She  is  given  enough  food,  vaccinated  against  diseases,
protected  against  the  elements  and  artificially  inseminated.  From  an  objective
perspective, the sow no longer needs to explore her surroundings, socialise with
other  pigs,  bond  with  her  piglets  or  even  walk.  But  from  a  subjective
perspective, the sow still feels very strong urges to do all of these things, and if
these urges are not fulfilled she suffers greatly. Sows locked in gestation crates
typically display acute frustration alternating with extreme despair.
15
This is the basic lesson of evolutionary psychology: a need shaped thousands
of  generations  ago  continues  to  be  felt  subjectively  even  if  it  is  no  longer
necessary  for  survival  and  reproduction  in  the  present.  Tragically,  the
Agricultural  Revolution  gave  humans  the  power  to  ensure  the  survival  and
reproduction of domesticated animals while ignoring their subjective needs.

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Sows confined in gestation crates. These highly social and intelligent beings spend most of their lives in
this condition, as if they were already sausages.
© Balint Porneczi/Bloomberg via Getty Images.
Organisms are Algorithms
How can we be sure that animals such as pigs actually have a subjective world
of needs, sensations and emotions? Aren’t we guilty of humanising animals, i.e.
ascribing human qualities to non-human entities, like children believing that dolls
feel love and anger?
In  fact,  attributing  emotions  to  pigs  doesn’t  humanise  them.  It  ‘mammalises’
them. For emotions are not a uniquely human quality – they are common to all
mammals (as well as to all birds and probably to some reptiles and even fish).
All mammals evolved emotional abilities and needs, and from the fact that pigs
are mammals we can safely deduce that they have emotions.
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In  recent  decades  life  scientists  have  demonstrated  that  emotions  are  not
some mysterious spiritual phenomenon that is useful just for writing poetry and
composing  symphonies.  Rather,  emotions  are  biochemical  algorithms  that  are
vital  for  the  survival  and  reproduction  of  all  mammals.  What  does  this  mean?
Well, let’s begin by explaining what an algorithm is. This is of great importance
not  only  because  this  key  concept  will  reappear  in  many  of  the  following
chapters,  but  also  because  the  twenty-first  century  will  be  dominated  by
algorithms.  ‘Algorithm’  is  arguably  the  single  most  important  concept  in  our
world.  If  we  want  to  understand  our  life  and  our  future,  we  should  make  every
effort  to  understand  what  an  algorithm  is,  and  how  algorithms  are  connected
with emotions.
An  algorithm  is  a  methodical  set  of  steps  that  can  be  used  to  make

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calculations,  resolve  problems  and  reach  decisions.  An  algorithm  isn’t  a