Mankind Rising - Where do Humans Come From

Summary

The script narrates the improbable and extraordinary journey of human evolution over 4 billion years. Starting from a single cell in a primordial soup, life on Earth faced numerous challenges, including disasters and predators, leading to the emergence of diverse species. Key evolutionary milestones include the development of sight, the transition from water to land, and the ascent of mammals after a mass extinction event. The narrative highlights significant adaptations, such as the shift to bipedalism and the development of complex brains, culminating in the emergence of Homo sapiens as the dominant species on the planet.

Takeaways

• 🧠 Humans are the most complex creatures on Earth with a big brain and two-legged mammal characteristics, having evolved from the raw materials of the Earth.
• ⏳ The story of human evolution spans nearly 4 billion years, involving numerous evolutionary twists and turns, and overcoming various disasters and predators.
• 🌊 Water is essential for the origin of life, and it's believed that asteroids or comets delivered water to Earth, creating a soup of chemicals and organic compounds.
• ⚡ Life began with a single cell, which through a series of improbable events, including lightning strikes, formed the first genetic material.
• 🔬 The first living thing was a cell that could reproduce itself, and all life on Earth can trace its origins back to this single cell.
• 🧬 Sexual reproduction introduced variation through the combination of genes from two cells, leading to the evolution of distinct species.
• 🐟 Our ancestors evolved from water-dwelling creatures to land-dwelling beings, adapting to various environmental challenges along the way.
• 🦷 Developments such as jaws and teeth allowed our ancestors to consume more food and grow stronger, contributing to their survival.
• 🦂 A catastrophic event 250 million years ago led to the extinction of 95% of all species, but a few, including our distant ancestors and dinosaurs, survived.
• 🦇 After the extinction of the dinosaurs, small, rat-like mammals faced the challenge of surviving in a devastated world, leading to the rise of mammals.
• 🕊 The evolution of bipedalism in our ancestors allowed them to walk on two legs, freeing up their hands for tool use and other activities.
• 🔨 The ability to make and use tools was a significant milestone in human evolution, enabling us to manipulate our environment and improve our survival chances.
• 🔥 The control of fire for warmth, light, and cooking was a transformative step, providing safety and a means to prepare food more easily.
• 🗣️ The development of speech allowed for complex communication, cooperation, and the formation of societies, distinguishing humans from other species.
• 🌏 Homo sapiens, meaning 'wise man', emerged around 200,000 years ago with the largest brain of any creature, capable of spreading across continents and adapting to various environments.

Q & A

How did life on Earth begin according to the script?

Life on Earth began through a series of improbable coincidences. Experts believe that water, delivered by asteroids or comets, was essential. The water, filled with chemicals and organic compounds, was struck by lightning, which provided the energy to trigger a chain of events that led to the formation of genetic material. This material was then engulfed by a blob of oily material to create the first cell.

What is the significance of the first living cell in the script?

The first living cell is significant as it is the origin of all life on Earth. It was capable of sending out chemical instructions and reproducing itself to create a perfect clone, marking the beginning of life's diversity and evolution.

How did the process of sex contribute to the evolution described in the script?

Sex introduced variation into the evolutionary process by combining genes from two cells, leading to offspring with traits from two parents. This increased genetic diversity and allowed for the development of distinct male and female sexes, which was crucial for the survival and evolution of species.

What adaptation allowed our ancestors to move from water to land?

A significant adaptation that allowed our ancestors to move from water to land was the evolution of the ability to breathe air. This was triggered by the need to survive in stagnant water where oxygen was scarce, eventually leading to the development of lungs.

What evolutionary advantage did the development of sight provide?

The development of sight provided a critical evolutionary advantage by allowing our ancestors to differentiate between dark and light, find more prey, dodge predators, and thus live longer and produce more offspring.

How did the extinction event 250 million years ago impact the evolution of life on Earth?

The extinction event 250 million years ago, caused by volcanic eruptions in Siberia, wiped out 95% of all living species. This catastrophe allowed the small reptiles that survived, including our ancestors and the dinosaurs, to evolve and adapt, eventually leading to the rise of mammals and dinosaurs.

What adaptation allowed our ancestors to survive the harsh conditions after the asteroid strike 66 million years ago?

After the asteroid strike, our mammal ancestors survived by becoming smaller and nocturnal, which made them harder to catch and see. They also developed tough skin to protect from the sun and claws that helped them move across rough terrain.

What significant evolutionary step did 'Ardipithecus ramidus' represent?

Ardipithecus ramidus represented a significant evolutionary step as it was the first of our ancestors to walk on two legs, freeing up hands for other tasks like picking food. This bipedalism was a key adaptation that changed the course of human evolution.

How did the development of tools impact human evolution?

The development of tools had a profound impact on human evolution. It allowed our ancestors to access new food sources, such as bone marrow, by creating the first tools. This innovation led to a cascade of advancements, including the growth of our brains and the eventual development of complex societies.

What role did cooking play in the evolution of 'Homo erectus'?

Cooking played a crucial role in the evolution of Homo erectus. It made food easier to digest, freeing up energy for brain development. The consumption of cooked food also led to a reduction in the size of molars, as the need for powerful teeth to chew raw food decreased.

How did the development of speech contribute to the evolution of 'Homo sapiens'?

The development of speech was a pivotal moment in the evolution of Homo sapiens. It allowed for complex communication, cooperation, and the passing of knowledge between individuals, which was essential for survival and the building of societies.

Outlines

00:00

🧬 The Dawn of Life: From Single Cell to Complex Creatures

This paragraph delves into the origins of life on Earth, tracing the evolutionary journey from the first single-celled organism to the emergence of complex life forms. It highlights the improbable and extraordinary sequence of events that led to the creation of life from a lifeless ball of rock and dust. The narrative emphasizes the role of water, the delivery by asteroids or comets, and the formation of the first cell through a series of fortunate coincidences. The paragraph also touches on the significance of genetic material, the first instance of cellular reproduction, and the introduction of sex as a catalyst for variation and the emergence of distinct species.

05:02

🐍 Evolution's Path: From Water Worms to Land Creatures

The second paragraph continues the evolutionary saga, focusing on the development of vision and the transition from aquatic to terrestrial life. It describes how a water worm, our ancestor 550 million years ago, evolved to develop light-sensitive cells, which eventually led to the formation of eyes. This adaptation provided a significant advantage in the ancient oceans, allowing for better predation and evasion of predators. The paragraph also discusses the process of natural selection, the evolution of jaws and teeth for better feeding, and the challenges faced by our ancestors, such as the great white of the ancient oceans, which posed a threat to their survival.

10:02

🦈 The Struggle for Survival: Adapting to Land and the Loss of Gills

This section of the script details the challenges and adaptations our ancestors faced as they moved from water to land. It discusses the evolutionary leap of developing lungs to breathe air, a response to stagnant water conditions that lacked oxygen. The narrative explains how our ancestors, like the ichthyostega, adapted to life on land with thicker skin and tough claws, eventually leading to the development of a tough-shelled egg and the birth of live young. The paragraph underscores the significance of these adaptations in shaping the future of our species and the emergence of mammals.

15:06

🔥 The Great Dying and the Rise of Mammals

The fourth paragraph discusses a pivotal moment in Earth's history: the 'Great Dying' event 250 million years ago. This catastrophic event, triggered by volcanic eruptions in Siberia, led to a mass extinction with 95% of all species perishing. The paragraph describes how our ancestors, small and fur-covered creatures called ectoninion, survived this apocalyptic scenario. It also highlights the emergence of dinosaurs as the dominant species post-extinction and the subsequent competition for survival between them and our mammalian ancestors.

20:19

🦕 The Dinosaur Era and the Evolution of Mammals

This paragraph explores the relationship between the dominance of dinosaurs and the evolution of mammals. It explains how the presence of dinosaurs influenced the development of our ancestors' senses and brains, as well as the shift from laying eggs to giving birth to live young. The narrative also recounts the asteroid impact that led to the extinction of dinosaurs 66 million years ago, setting the stage for mammals to rise as the new dominant species on Earth.

25:32

🌳 Life in the Trees: The Primate Ancestors

The sixth paragraph shifts the focus to the arboreal lifestyle of our primate ancestors, the alti atlassias. It describes how changes in the environment, such as shrinking forests and temperature fluctuations, led to adaptations that allowed these early primates to thrive. The paragraph also discusses the formation of the East African Rift Valley and its impact on our ancestors' evolution, as they were forced to adapt to new challenges in their search for food and survival.

30:35

🦶 The Bipedal Revolution: Walking on Two Legs

This section of the script marks a significant turning point in human evolution: the development of bipedalism. It tells the story of artipithicus ramidus, an early hominid that walked on two legs, freeing its hands for other tasks. The paragraph explains how this adaptation allowed our ancestors to cover greater distances in search of food and resources, and how it led to further evolutionary changes, such as the development of a larger brain and the need for parental care due to the challenges of childbirth with a narrower pelvis.

35:39

🛠 The First Toolmakers: The Emergence of Homo Habilis

The seventh paragraph introduces homo habilis, or 'handyman,' the first of our ancestors to create and use tools. It discusses how this development marked a new phase in human evolution, enabling our ancestors to manipulate their environment more effectively. The narrative also touches on the importance of tool use in shaping our ancestors' bodies, particularly the evolution of stronger thumbs and the development of more complex cognitive abilities.

40:43

🔥 Fire and Family: The Evolution of Homo Erectus

This section highlights the emergence of homo erectus and the significant advancements in human behavior and social structure. It describes how the control of fire provided warmth, light, and safety, and how the ability to cook food led to physiological changes, such as a reduction in the size of molars and an increase in brain size. The paragraph also discusses the importance of communication and cooperation within early human families and the development of speech as a critical tool for survival and social cohesion.

🌏 Homo Sapiens: The Masters of the World

The final paragraph of the script celebrates the arrival of homo sapiens, the wise men, who emerged as the most intelligent and adaptable species on the planet. It recounts the journey from the first single-celled organisms to the complex human societies that now dominate the Earth. The narrative emphasizes the uniqueness of our evolution, the near impossibility of its replication, and the remarkable story of our 4-billion-year-long struggle for survival and dominance.

Keywords

💡Evolution

Evolution refers to the process by which species of organisms change over time through genetic variation and natural selection. In the video's theme, it is the central concept that explains how life on Earth has developed from simple single-celled organisms to complex creatures like humans. The script mentions 'nearly 4 billion years of evolutionary twists and turns' to illustrate the long and intricate path that has led to the current diversity of life.

💡Natural Selection

Natural selection is the mechanism by which species adapt to their environment and evolve over generations. It is a key driver of evolution and is defined as the process where traits that enhance survival and reproduction become more common in successive generations. The script uses the phrase 'natural selection in action' to describe how our ancestors developed eyes, a critical adaptation that allowed them to better see and survive in their environment.

💡Mutation

A mutation is a change in an organism's genetic material, which can lead to variations in traits between individuals. In the context of the video, mutations are portrayed as a source of diversity and a catalyst for the development of new species. The script mentions 'mutations pile up differences increase' to emphasize how these genetic changes can accumulate over time, leading to the emergence of distinct species.

💡Extinction

Extinction is the permanent loss of a species. It is a natural part of Earth's history, but it can also be accelerated by human activities. The video script refers to several instances of extinction, such as 'predators threaten to wipe us out' and '95 of all species die' during a catastrophic event, highlighting the fragility of species and the constant struggle for survival.

💡Adaptation

Adaptation in biology is the process by which an organism or species becomes better suited to its environment, often through the development of new traits. The video script describes various adaptations, such as 'thicker skin protects us from the sun' and 'tough claws that will one day become our fingernails,' which illustrate how species evolve to cope with new challenges and environments.

💡Ancestral Lineage

Ancestral lineage refers to the evolutionary history of a species, tracing back through the generations to its earliest known ancestors. The video script outlines our ancestral lineage from 'a single simple self' to 'a three-inch long water worm' and beyond, emphasizing the gradual development of human characteristics over billions of years.

💡Genetic Material

Genetic material is the substance in an organism's cells that carries genetic information, such as DNA. In the video, the creation of the first cell is described as involving 'a bundle of genetic material,' which is crucial for the transmission of hereditary traits and the beginning of life as we know it.

💡Mass Extinction

Mass extinction is an event that results in the widespread and rapid loss of numerous species. The script describes a mass extinction event where '95 of all species die,' caused by volcanic eruptions and an asteroid strike, which significantly altered the course of life on Earth and paved the way for the rise of mammals, including humans.

💡Hominids

Hominids are members of the taxonomic family Hominidae, which includes modern humans, our immediate ancestors, and several extinct hominid species. The video script mentions 'homo habilis' and 'homo erectus,' which are both hominid species that played a significant role in human evolution, with 'homo habilis' being the first to use tools and 'homo erectus' being the first to control fire and cook food.

💡Bipedalism

Bipedalism is the ability to walk upright on two legs. The video script highlights bipedalism as a critical evolutionary development with 'artipithicus ramidus' taking 'our first steps on two legs,' which freed up our hands for tool use and other activities, and became a defining characteristic of the human lineage.

💡Tool Use

Tool use is the manipulation of objects in the environment to achieve a goal, which is a sign of advanced cognitive abilities. In the script, 'homo habilis' is described as 'the first of an entirely new type of creature,' known for making and using tools, which marked a significant step in human evolution and our ability to shape our environment.

Highlights

Human evolution is an improbable and extraordinary story spanning nearly 4 billion years.

Life on Earth began from a ball of rock and dust, evolving into a planet teeming with nearly nine million species.

The origin of life is theorized to have started with water delivered by asteroids or comets.

The first living cell was formed through a series of improbable coincidences and chemical reactions.

Natural selection and genetic mutation led to the diversification of life from single-celled organisms to complex creatures.

The development of sight was a critical evolutionary advantage, allowing early creatures to find prey and avoid predators.

The first brain evolved around 521 million years ago in a fish-like creature, marking a significant step in cognitive development.

Adaptation to land involved the evolution of thicker skin, tough claws, and eventually, the development of lungs.

The transition from water to land was a pivotal moment in the evolutionary history of our ancestors.

The evolution of sexual reproduction introduced genetic variation, leading to the emergence of distinct species.

A mass extinction event 250 million years ago wiped out 95% of all species, paving the way for the rise of dinosaurs and mammals.

Mammals evolved to fill the ecological niches left by the dinosaurs after a catastrophic asteroid impact 66 million years ago.

The development of complex brains in early mammals allowed for advanced problem-solving and adaptation.

Bipedalism emerged as a key evolutionary adaptation, freeing up hands for tool use and manipulation.

The invention of tools marked a significant milestone in human evolution, enabling early humans to shape their environment.

The use of fire for warmth, light, and cooking was a transformative development in human society.

The emergence of Homo sapiens around 200,000 years ago signifies the arrival of modern humans with advanced cognitive abilities.

Language and communication were crucial for social cohesion and the survival of early human communities.

The journey of human evolution is a story of adaptation, survival, and the rise to dominance on Earth.

Transcripts

we are the most complex creature

on this planet a big brain two-legged

mammal

we've risen from the raw materials of

the earth

to dominate and shape it

wind the clock backwards and the story

of how we got to be us

is a puzzle that defies all logic

through nearly 4 billion years of

evolutionary twists and turns

disasters strike predators threaten to

wipe us out

from rodent to reptile

we face extinction at every turn

from the land into the water fighting to

survive

every step of the way

from fish to worm back to the very first

spark of life

to a single simple self

this is the most extraordinary

improbable story ever told

the story of mankind rising

four billion years ago a ball of rock

and dust

spins in the frozen vacuum of space

this isn't mars

or venus

this hell is earth

this seething lifeless mass of molten

lava will become home to nearly nine

million living species

but generating life from this will take

a chain of events that defies the laws

of probability

there are many theories nobody knows

exactly

how or where life began

but it couldn't happen without water

experts believe asteroids or comets

delivered it here

the water is churning with chemicals and

organic compounds

lightning strikes the chemical suit at

the right place

and the right time billions of volts of

electricity

trigger a chain of improbable

coincidences

the chemicals atoms join up in a precise

sequence

creating a bundle of genetic material

these fragile genes don't stand a chance

in this extreme environment

[Music]

but luck strikes again a blob of oily

material engulfs a single chain

to create the first ever cell

now the genes send out messages

chemical instructions and 3.5 billion

years ago they do something

extraordinary

they copied themselves and the cell

to create a perfect clone

this is the very first living thing

every human every animal every bug

every plant can trace its origins to

this single cell

the genes tell each cell to reproduce

guaranteeing their survival

as they pass from one generation to the

next

for two billion years the only living

things

are simple single cells but a random

accident changes everything

two cells merge their genes

combine the merged cell clones itself

its offspring contains genes from not

one but two cells

two parents we call this accident

sex sex introduces variation

occasionally things go wrong as the

cells reproduce genes get deleted

duplicated these cells are mutants

mutations pile up differences increase

until the cells become so different

they're separate species

the tree of life branches out into

billions of species

but only one will lead to us

mutating and diversifying spreading out

through the oceans

getting bigger more complex

until our ancestor is a three inch long

water worm

this is us 550 million years ago

mutations create distinct male and

female sexes

we produce more offspring passing on

more genes

[Music]

mars and venus boy meets girl

it all starts here

but finding a partner is almost

impossible

when every living thing is blind

in this sea of darkness the ability to

see will give us a critical advantage

nature's most perfect innovation begins

to take shape

a handful of skin cells mutate

now we can tell dark from light

find more prey dodge more predators

we live longer and produce more

offspring

soon creatures with light-sensitive

cells dominate the population

over countless generations more

mutations refine the cells

this is natural selection in action the

process that allows every living thing

to adapt to the world

and that gives our ancestor eyes

we can see and everything we can see is

descended from that first single cell

but we need to make sense of what we're

seeing

behind our eyes a tiny collection of

nerve cells cluster together

they're no bigger than a pinhead

one day this will be nature's most

complex and mysterious

organ 521 million years ago

this is the very first brain

we are a fish-like creature called milo

conningia

our brain can make simple decisions

process basic information

but we can't outwit or outrun

this

anomalous the great white of the ancient

oceans

our odds of extinction are far higher

than survival

of all the species that have ever lived

99

of them are extinct

but a lucky roll of the genetic dice

helps milo toughen up

your jaws your teeth

they exist because over 400 million

years ago

we faced the wrath of a primeval monster

jaws and teeth mean more food and a

bigger

stronger body until

375 million years ago

we're a foot long armored fish

we look invincible

but we're not

now the choice is simple get out of his

way

or die

[Music]

we're safe in the shallow water or

are we the water's stagnant

there's not enough oxygen

starved of oxygen cells shut down

toxic carbon dioxide saturates the blood

we can't go back we can't stay here

there's only one place left for us to go

it takes over three billion years for

our ancestor to evolve from a single

cell

to a foot long armored fish

now our future looks bleak

but natural selection throws us a

lifeline

over millions of years thousands of

generations

our body adapts until we do something no

fish has done before

breathe air

the air travels into a new organ

a lung take a breath

and remember it's because a monster fish

chased our ancestor into the stagnant

water

forcing them to breathe air

we're an ichthyostega we can breathe

air or water closing off our windpipe

to switch between lungs and gills today

our gills are gone

but the mechanism remains and sometimes

it spasms

giving us the hiccups

365 million years ago

we stick our head out of the water

there's a swamp behind us paradise

ahead the choice is simple

but the consequences are immense

we pull ourselves out of the water and

change the course of history

this is the moment we leave the water

for a new life on land

but all this food comes at a price

the fierce sun dries out our skin

the hard terrain tears at our soft feet

ichthyostega is a fish out of water

[Music]

we dodged extinction in a stagnant swamp

only to slam straight into another

deadly environment

countless creatures perish but natural

selection

helps our ancestor adapt

[Music]

thicker skin protects us from the sun

and tough claws that will one day become

our fingernails

help us move across the rough terrain

until we're casanaria

we've adapted to life on land but our

eggs haven't

they need a tough shell to stop them

drying out in the sun

the problem is males can't fertilize an

egg through a tough shell

but they can fertilize it before the

shell forms

inside the female's body

sex as we know it starts here

the result is a masterpiece of evolution

an egg in a tough shell with all the

nutrients the embryo needs sealed inside

sex is the best way to increase genetic

variety and keep our species alive

[Music]

thanks to sex 340 million years ago

cassanaria becomes the first of our

ancestors to live entirely on land

it's a new world different from anything

we've experienced

up to now we breathe air

support our own weight and wrestle with

an

onslaught of new smells sounds sights

[Music]

bombarded with information our brains

evolve

we're smart and we need to be

from that first creature to set foot on

land

millions of species have evolved

more competitors mean less food to go

round

a mutation gives us bigger more powerful

jaw muscles

it's a critical advantage we can eat

more food

faster

and it shows

a slab of pure meat eating power

this little creature is a proterosaurus

once a competitor now he's prey

with varanops for an ancestor our

success seems certain

but our story is a roller coaster ride

and there's a big dip coming

250 million years ago thousands of miles

away

in siberia the earth tears itself apart

a giant plume of magma surges up from

deep inside the planet

molten rock oozes through cracks in the

earth's crust

covering an area the size of the united

states under a layer a thousand feet

deep

and it continues for half a million

years

trillions of tons of noxious carbon

dioxide trapped the sun's heat

inside the atmosphere

temperatures soar to over a hundred

degrees

plants the plant eaters and eventually

the meat eaters

perish 95 of all species die

only a tiny handful hang on

among them us and another species

that will one day become the dinosaurs

as the fight for survival winds down the

battle for supremacy

begins

30 million years since volcanic

eruptions wiped out 95 percent of all

living things

when the eruption struck we looked like

a large lizard

now we're a cat-sized creature covered

in fur

called ectoninion

imagine you've survived the apocalypse

and today is the day

it's finally safe to venture out of

hiding

you discover you're not alone

the last thing you want to see is a

dinosaur

a five foot tall herrerasaurus

she evolved from one of the small

reptiles that survived the mass

extinction her ancestors adapted faster

than

ours putting the dinosaurs ahead in the

game

and leaving us playing catch-up

[Music]

this one's fast strong

and hungry

[Music]

we're staring down the barrel of an

evolutionary gun

our only hope natural selection

over millions of years we get smaller

so we're harder to catch we become

nocturnal making us harder to see

we're cold and scared tiny muscles

around the base of each hair contract

making our fur stand on end trapping air

as insulation

that's why today when we're cold or

startled we get

goosebumps

our senses sharpen so we can see hear

and smell a dinosaur before a dinosaur

sees us

inside our brain a new structure evolves

the neocortex the home of complex

thought

that allows us to analyze a situation

and respond

it will one day give us the power to

imagine

create and communicate

66 million years ago we're batadong

a two-inch-long shrew-like creature

living on our wits

in the ancient forests of montana

humanity's future depends on vatadon's

sharp senses

and supercharged brain if these fail

we may never exist

my

[Applause]

[Music]

the dinosaurs may be the best thing that

ever happened to us

thanks to them we have powerful senses

and brilliant brains

without them we could still be laying

eggs

to protect our offspring from hungry

dinosaurs

we evolved to give birth to live young

instead of leaving them to fend for

themselves

we nurture them with milk

sweat glands evolve to become mammary

glands

it's a major milestone in our journey

from cell to human

the birth of a new kind of animal

one that will branch out into more than

four thousand species

from the smallest mouse to the largest

whale

to us the mammals have arrived

the dinosaurs helped shape who we are

but we lost the battle for supremacy

the dinosaurs reigned for over 165

million years

nothing can stop them or so it seems

montana 65 million years ago

an asteroid strikes 1800 miles away

off mexico's yucatan peninsula

a small rat like mammal is about to face

the fight of his life

lose and humans may never exist

pulverized rock and dust engulfed the

entire planet

[Music]

the only way out is to dig

smoke and ash from the fires block out

the sun

temperatures plummet vegetation dies

the local disaster becomes a global

catastrophe

for the dinosaurs it's a disaster

they're big creatures with big appetites

and now that's a big problem

as the mighty fall the small rise to the

top

bugs tough enough to survive the worst

catastrophe

gorge on the dead and decaying

and they make the perfect snack

next time you're about to squash a bug

remember that we wouldn't be here

without them

64 million years ago our bug-eating

ancestor

is purgatorious just under six inches

long

this little creature and the rest of his

mammal family are the unlikely

inheritors of the dinosaurs crown

mammals become the dominant animals on

land

they spread out across the newly formed

continents

our future rests on their tiny shoulders

from the ashes of destruction new life

begins to sprout

60 million years ago fruit ripens on the

trees

packed full of nutrients the more fruit

we eat

the longer we live we leave solid ground

for a new life in the trees

a new world demands a new body

we've come a long way from that first

single cell

now at last we're beginning to glimpse a

family resemblance

[Music]

we're alti atlassias one of the first

members of a new group of mammals

the primates

by 56 million years ago we've adapted to

our world

[Music]

but that world is about to change again

over 10 million years extreme

temperature shifts ravaged the forests

forests get smaller food gets harder to

reach

natural selection intervenes

our again shrinks back to the base of

the spine

where it stays as the coccyx

a reminder of our days spent leaping

through the trees

instead of leaping we stretch

our arms grow long and flexible

changing temperatures changed our

ancestors

and us forever but the planet's not

finished yet

deep underground the african and arabian

plates pull apart the land between them

drops to form the east african rift

valley

along its edge a three and a half

thousand mile long mountain chain

rises up

rains from the indian ocean once watered

all of africa

now the mountains blocked their path

the trees get even further apart the

food harder to reach

we're starving desperate

4.4 million years ago the will to

survive

that's driven us from a single cell in

the ocean

to a complex primate in the forests of

africa

is about to make us do something

extraordinary

something no primate has ever done

before

after three billion years of evolution

we hit an evolutionary dead end

we're artipithicus ramidus four feet

tall

at 80 pounds with a brain the size of an

orange

our dense rainforest home has become

patchy forest

we can stand on branches move along them

but to reach more food we need to let go

[Music]

[Music]

4.4 million years ago

these are our first steps on two legs

walking takes us to the food and leaves

our hands free to pick it

it catches on fast

art epithecus is smart enough to copy

and learn

walking gets passed from parent to child

over the next 1.2 million years our body

evolves so that we can walk further

and faster

[Music]

finding shelter a mate and food

gets easier but childbirth gets harder

with a narrower pelvis giving birth to a

fully developed infant

becomes impossible

babies have to come out early when their

heads are smaller

and they're barely developed that's why

we are one of the few species to spend

years caring for our offspring

protecting them feeding them and keeping

them out of trouble

3.2 million years ago we're an

australopithecuan

our brain is the size of a grapefruit

and we walk on two legs

all the time

[Music]

so

we got lucky the lion has already eaten

this time we can't outrun our predators

the only way to survive is to out-think

the smarter we get the longer we live

natural selection promotes the mutations

that improve our brain power

like weaker jaw muscles

released from the muscle's vice-like

grip the brain is free to grow

it doubles in size

2.3 million years ago this

is homo habilis also known as

handyman

walking on two legs with a big brain

we're the first of an entirely new type

of creature

we're the first man we're bigger

stronger and hungrier than ever before

there's food out there but it's more

likely to eat us

before we can eat it

we're a scavenger working alone

we eat whatever we can find

the edge is razor sharp

we have just made the very first tool

armed with this we will change the world

east africa 2.3 million years ago

after over three billion years of

evolution we take our fate into our own

hands

we are the first species to make tools

in this hostile environment we need

every advantage we can get

we must fight off predators starvation

and our own relatives

[Applause]

[Music]

there's no meat left it looks like we're

going hungry again

but there's bone marrow locked inside

packed with energy

the tool is the key to a whole new way

of life

we'll use it to grow crops build cities

and travel into space our thumbs become

stronger

hold a cup pick up a pen

we can do this because two million years

ago tool use

changed our bodies in the course of

evolution

we've pieced together our ancestors

story from their bones

but from the vastness of africa all the

bones of our early human ancestors ever

found

would fit into the back of a pickup

less than one bone in a billion becomes

a fossil

factor in the chances of finding those

bones across millions of square miles

and it's clear most of what has lived

has been lost our family tree is a giant

puzzle

with most of the pieces missing

but 1.8 million years ago a piece falls

into place

and we find a new species on the scene

homo erectus

until this point we were scavengers

but now we're hunters

and we've learned how to work with other

members of our species

[Music]

the hunt is on

the impala can run fast but we can run

further low shoulders and long torsos

stabilize us

powerful buttock muscles contract expand

and push us forwards

[Music]

sweat stops us from overheating

covered in fur the impala is exhausted

fire

it sparks an idea that will make our

ancestors

human

warmth light safety is within reach

nature's power is in our hands

protected from the terrors of the dark

our extended family gather round

by working together these earliest

families get food more often

so we live longer

this is the advantage of family life

the reason most of us live as we do

today

meat is too precious to waste

and cooked meat is easier to chew

the powerful molars used to chew tough

raw food

retreat back into the gums where they'll

stay

as our wisdom teeth 35 of us

never even grow them a sign that they

may be evolving out of existence

with less energy spent on chewing our

ancestors

have energy to spare the brain increases

to the size of a softball

50 percent larger than before the

invention of cooking

erectus is the cleverest most

cooperative ancestor to date

but with several adult males in an

extended family

rivalries are inevitable

communicate and will live longer

natural selection kicks in our tongue

changes shape

and moves down our throat carrying the

larynx with it

allowing us to form different shapes in

our mouths

making different sounds and ultimately

words speech is our greatest tool

it's the last piece of the puzzle that

turns our ancestors into

us 200

000 years ago after a 3.3 billion year

battle for survival

we've arrived

we are homo sapiens meaning wise men

pound for pound we have the largest

brain of any creature on earth

armed with tools speech and superior

intelligence

we spread out across every continent

we evolve and adapt to new environments

new challenges

until we become the undisputed masters

of the world

wind the clock of life back to the

beginning and the chances of us evolving

again

are practically zero change one thing

one predator one lucky mutation and we

wouldn't be here to tell the tale

to piece together the extraordinary

story of our

4 billion year journey