All language subtitles for Evolution.2026.S01E02.The.Ostrich.1080p.iP.WEB-DL.AAC2.0.H.264-playWEB_track3_[eng]

They're not the prettiest...

..or the brightest...

..and it's fair to say...

..they're a bit odd.

But ostriches produce something
truly astonishing...

..the biggest eggs on the planet.

Can I ask you to stop for a moment

and think about something
truly remarkable?

Something so commonplace,
so everyday, that we

take it for granted.

Life creates new life,

and it's happening right
here in front of me.

If I bend down...

RATTLING
Oh, yes! I can hear it!

I can hear it tapping.

It's as if it's yearning
to get out of the egg.

Oh!

And you know, around 40 days ago,
the chick that's just about to break

out of here into the big wide world
was just a tiny collection of cells.

And look at this, it's started!

I can see inside,
I can see its little eyes, its beak.

It's blinking at me.

CHIRPING
Oh!

It's quite emotional,
if I'm honest with you!

CHIRPING CONTINUES

So, how did this
marvel of nature come to be?

Well, to answer that question
we have to travel back...

..way back...

..before birds...

..before dinosaurs...

..before there were even eggs...

..following an unbroken chain of
life that stretches back

over four billion years.

This is the extraordinary
story of how evolution gave

rise to the ostrich,
and its enormous egg.

THUNDERCLAP

These are some of the world's
first living things.

They can't see, they can't hear...

..but right from
the very beginning,

life on Earth was really
good at one thing...

..reproducing.

But back then, they did it in a way
that seems quite alien to us.

They split themselves in half
to create an identical copy.

A clone.

As soon as life appeared on Earth,
it began reproducing

and once it started,
it did so at a remarkable rate,

churning out copy after copy after
copy for billions of years.

The problem is, though, that
when you're just copying yourself,

it means that life's scope
is quite limited.

You see, for billions of years
we had nothing with eyes,

nothing with legs, nothing with
a brain, just single-celled

microbes, and it looked like life
was just going to stay like that.

Imagine a world filled with nothing
but microbes.

No plants, no insects,
no birds of any kind.

And definitely no people.

You see, it's not that I've got
anything against microbes,

but let's face it,
life would be dull.

But for almost two billion years,

that's exactly how life was.

There was some mixing of DNA

and different
species of microbe evolved.

But the chances of life getting any
bigger than a pinhead looked slim.

Until...

..somewhere in this
sea of simple cells...

..a revolutionary emerges.

Now, it may seem similar to all
the microbes that came before it,

but it is in fact on a new
branch of the tree of life.

You, me and the ostrich -
we are all here today

because this microbe does
something scandalous.

It takes a shine to another microbe.

Their cell membranes fuse,

allowing all their DNA to mix.

This is the first sex...

..and it would change
the course of life on Earth forever.

It certainly wasn't romantic
and it wasn't earth shattering,

but the first sex was
a very big deal.

And to understand why,
we need to understand what sex is,

and I know what you're thinking,
don't worry. No naff diagrams.

Fundamentally,

sexual reproduction is about two
living things coming together

to share their genes, to create new
life, a new life which is unique.

And that's why the first sex
was so pivotal, because after

billions of years of just copying,
here was a chance for mixing.

The first sex set
life on a new path.

The offspring of this pair won't
be clones of their parents.

Instead, they'll inherit a random
mix of genes from both.

Sex creates variety

and it sends
evolution into overdrive.

Let's fast forward through the next
one and a half billion years...

..during which time there
is a sexual revolution.

Some cells join forces...

..leading to big, complex bodies...

..the first animals.

By the Cambrian period,

the oceans are filled with a huge
diversity of animal life...

..from simple sponges to species

with eyes, legs and shells.

But all share one thing in common...

..they're a randy bunch.

We have a good understanding of how
rich and varied life was in the

Cambrian seas, down to the enormous
abundance of fossils that we've

recovered from that period, and
you know how much I love a fossil.

Look at this Trilobite.
What a beauty!

You can see it's
got its segmented body here,

its rounded, smooth head,
compound eyes.

And I can tell you that
we've identified no less

than around 20,000 different
species of Trilobite.

I've got another fossil here.
Look at this.

This is an Eocrinoid,

an animal that's related to the sea
urchins, and we think that the

bottom part of it here was rooted
into the seabed and these tendrils

here would have been wafting
in the water flow, getting its food.

So, there was a great diversity
of life in those Cambrian seas,

but also a diversity of shape
and size,

and that made sex altogether
more challenging

because organisms like this couldn't
reproduce in the same way that their

ancient single-celled ancestors did,
by simply fusing together.

I mean, imagine a couple
of trilobites like this trying

to get it on. It's not going
to work, is it,

with the hard exoskeleton, all of
their legs, their internal organs?

Nature needed to come up
with a different way.

And nature's solution is
an extremely effective one.

Back in the Cambrian,
many animals have adopted it.

These tiny specks are eggs...

..and these even tinier
ones are sperm.

And they do exactly what those
ancient microbes did.

They fuse together
and combine their DNA

to create a new, unique life.

The Cambrian seas are quite
literally fertile oceans...

..but for many creatures here,

there's something unfamiliar about
the way they go about reproducing.

A lot of people don't like snails.
I'm not one of them.

There's something therapeutic
about having them slime

up and down your fingers.

These are a highly successful
group of animals.

There are more
than 40,000 species in the world,

and one of the keys to their success
is their reproductive capacity.

Like many snails,
it produces sperm and eggs.

It's a hermaphrodite.

Let's think
about the repercussions of that.

When this snail goes looking for a
potential partner, any other that it

finds of the same species and about
the same size, is a potential mate.

And once they've copulated, they
can both produce a batch of eggs,

doubling the capacity to produce
a lot more snails.

Now, this is such an efficient
and successful strategy that many

scientists believe that the earliest
animals were all hermaphrodite.

As soon as they could produce sperm
and eggs, they produced both,

which begs the question, why aren't
we all hermaphrodites today?

It's hard to know for certain,
but there's a theory

that during the Cambrian,
something upset the status quo...

..and it may have
happened in a creature like this.

It's so bizarre, it's hard
to believe it really existed.

But fossil evidence shows that
it really did look like this.

It's a Vetulicolian.

It's not a fish,
it's not a crustacean.

In fact, it's unlike anything
that lives today...

..and it's radically different
from its single-celled ancestors.

But it has inherited a key trait -
a one-track mind.

Now, if we assume
Vetulicolians are hermaphrodites,

that means that any member of the
same species is a potential mate.

But when this pair come together
to release their eggs and sperm...

..there's a problem.

You see, one of them
was born partially sterile.

It can't produce sperm.

For many animals, this would be
the end of their family line...

..but not for a hermaphrodite.

Because if it can still
produce eggs...

..it can still reproduce.

Its genes get passed
down to the next generation...

..and some of them
are born partially sterile too.

So, think about it.

In biological terms, that snail,
if it could only produce eggs,

we'd call it a female.

If it could only produce sperm,
we would call it a male.

So, there is the possibility
that the division of the sexes,

the origin of males and females,
came down to a chance mutation,

that we were mistakes.

Today, only 5% of animal
species are hermaphrodites.

The rest have separate sexes,

and it's thought that males

and females evolved multiple times,
in many different species,

allowing females to
specialise in producing fewer,

higher quality eggs,

whilst males
make faster, more numerous sperm.

Nature is of course flexible.

Clownfish males can
turn into females...

..seahorse dads get pregnant.

It really doesn't matter
who does what.

it's being a specialist that counts.

For animal life, this
specialisation is a turning point.

As we jump forward 150 million
years,

it adds fuel to evolution's fire.

Fishes emerge
and fill every marine habitat.

And eventually,
some even brave a new frontier...

..the freshwater streams.

This ancestor of the ostrich
is looking for a safe place

to lay her eggs.

With streamlined bodies
and powerful tails...

..her shoal swim upstream with ease.

But...

..they're being followed.

If I were to time travel
back to the Devonian,

you would not find me
wading in a river like this.

No matter how sweaty the swamps
were, I wouldn't be tempted

to take to the waters because I
might lose my toes, or even my legs.

The rivers were filled
full of predatory fish,

armed with sharp teeth for tearing
through flesh.

Some of them the size of minnows,
others the size of crocodiles.

If you were a fish living in here,

you'd have enough trouble protecting
yourself, let alone your eggs.

Left unguarded in these
ancient waters,

nutritious eggs don't stand
a chance.

These fish need to find a safer
breeding ground...

..or there'll be no next generation.

But they have something
on their side that other fish don't.

This is a 3D scan of a fossil
of one of those fishes.

And when you first look at it,

it looks pretty much like a modern,
conventional fish - it's long,

fairly streamlined, it's got
a bit of a blunt head there,

would have had a tail at the back
for propelling it through

the water, and all of the fins
are pretty much in the right places.

Looks a little bit like a salmon,
but on closer inspection,

in fact it's very different.

Let's zoom in on this fin here.

You can see that it's much
longer and the bones that

lead from it back to the core of the
skeleton are much more robust.

It could be that it was using
these fins to propel

itself along the bottom
of the river.

They're much stronger than those
delicate ray fins that we

see on modern fishes. These are fins
that you could stand on.

The strong fins that help these fish
move along the riverbed also

allow them
to do something revolutionary...

..leave the river...

..and walk on land.

And beyond the main river lies
a network of streams

the predators can't reach.

We can't be certain why those
lobe-finned fish climbed

out of the water.
I mean, they could have been

looking for food, they could have
been avoiding being food themselves,

but there is the possibility

that they were looking for somewhere
safe to lay their eggs, to spawn.

But one thing's for sure,
once they waddled out of the water

and climbed onto land,
there was no going back.

Fish with the strongest
fins are more likely to reach

the predator-free waters.

They have more offspring,
which inherit their strong fins.

Over countless generations,
the bones get longer, stronger...

..and better for walking on land...

..until eventually,
after millions of years,

a fish's fin has become a limb.

There's absolutely no doubt
that this was a pivotal moment.

I mean, think about it.

Life on Earth had evolved in water,
and up until this point,

almost all life was still
living in water.

OK, around 100 million
years earlier,

plants have made the difficult
transition onto land,

insects had managed it, too,
but now here was a new group -

animals walking on land on four legs
and four feet for the first time.

The amphibians.

Now, I'm about to show you
something which is remarkable,

astonishing even,
and I think very beautiful.

Take a look at this.

This is a drawing of the bones
in the foot

of one of those ancient amphibians.

It lived over 300 million years ago.

But look at it.

Does it look familiar? It should do.

That's because these ancient
amphibians were our ancestors,

and not only our ancestors,
but the ancestors of all the animals

with backbones that have ever lived
or are living on land today.

If those ancient microbes hadn't
discovered sex, bigger,

more complex animals may
never have evolved.

We wouldn't have males
and females...

..with precious eggs,

that need protecting.

And the ancestors of every land
animal with a backbone,

including the ostrich, and us...

..may never have left the water...

..and evolved to live on land.

Now, we jump forward
tens of millions of years...

..and the amphibians are the
planet's dominant land animals.

But no reign lasts forever.

This is Casineria.

She can live happily in water
and on land...

..but like many animals here,
Casineria is in trouble.

Drought has set in.

Swamps that once stretched as far
as the eye can see are now

little more than muddy puddles.

To understand why this
was a problem...

..we only have to
look at amphibians today.

Clearly out of practice,
but I did manage to catch one.

This frog is rather attractive,
I have to say.

Look at those eyes,
like little golden jewels.

It looks slimy, but it's not.

It's shiny,
and it's shiny because it's wet,

and when it's wet, frogs like this
can breathe through their skin.

But it does need to be wet.

So, there's an inherent
vulnerability there.

They do need to return to water.
They can't dry out.

And it's not just the adults.

Their eggs need water too.

Amphibians can't reproduce
without water.

In periods of drought,
amphibians suffer.

But Casineria has managed
to cling on.

Her survival is partly down to luck,
but also,

the unique mix of genes
she inherited.

Now, had I been a bit sharper

and been able to catch another
one of these frogs,

then probably, to you and I, they
would look identical, like clones.

But of course they're not,
because frogs reproduce sexually.

They mix their genetic material
to produce unique individuals

and this doesn't only make life
more interesting.

Critically,
it makes life more resilient.

Think about it.

At this point in time,

this lovely stream is probably the
perfect place for this frog to be.

But what about if conditions change?

What about if it got drier or wetter
or the vegetation changed,

or something much more subtle like
the mineral content of the water?

Well,
because every frog is different,

some will fare better than others.

They'll live longer
and have more offspring, and those

offspring will inherit the genes
that helped their parents survive.

Essentially, that's what
we call survival of the fittest.

Casineria's unique mix of genes
determines everything from her

size to her skin colour.

And it also determines her eggs.

As luck would have it,

they're better at retaining moisture
than most amphibian eggs...

..and in these dry conditions,
that difference means everything.

The slightest variation in the
surface structure or composition

of the egg is all it takes for one
egg to survive

when others don't.

And as generations pass,
the egg begins to change.

The surface gets tougher
and thicker.

Special membranes form to prevent
moisture loss.

The egg gets larger, stronger,
and takes on an iconic shape...

..until eventually,
after millions of years,

something extraordinary
has emerged...

..an egg that can survive
on dry land.

From dying swamps, entirely new
groups of animals emerge.

Among them, the reptiles.

Look at this rock monitor,
what a beauty!

Sadly, you don't
have time to watch me

falling in love with a lizard,
so let's look at the similarities

between this animal
and those ancient amphibians.

Well, firstly,
it's got the same streamlined nose

and long tail there.

Then look at her limbs,
all four of those legs and feet,

strong with those sturdy
bones that have been

passed down generations
from the lobed-fin fishes.

But there are differences too.

The skin is a striking one.

I mean, that is not shiny,
moist and breathable.

It's scaly and hard.
It's about keeping moisture in.

And then critically,

this reptile doesn't need to
return to water to breed.

You see, the amphibians might have
been first to walk the Earth,

but they were always
limited by that need for water.

It was the reptiles which really
conquered the land.

Reptile eggs are far more
sophisticated than the jelly

blobs of the amphibians.

Known as amniotic eggs,
they have a tough outer shell,

a nutrient rich yolk, and perhaps
most extraordinary of all,

a special
sac of fluid in which the embryo

floats in its own private pool.

The amniotic egg
is like a pond on dry land.

But when it came to sex,

these new high-tech reptile eggs
presented some challenges.

You see, an egg like this,

and this is a crocodile's egg,
is no good on its own.

It's got to be fertilised.

But there is absolutely no chance

of a sperm breaking through this
shell, so what's the solution?

Well, the solution is to get
the sperm to the

egg before the shell goes on,
before the egg is laid.

You see, the reptiles didn't only
have to reinvent the egg,

they had to reinvent sex.

The solution is found on almost
every male reptile today.

It begins to grow around the tenth
day of life.

A tiny bud, like an extra limb.

It's a penis.

Reptiles were amongst the first
animals to get penises...

..but they certainly
weren't the last.

The blue whale has the largest,
averaging 2.5 metres.

The gorilla has one of the smallest,
compared to its body size.

Duck penises are shaped
like corkscrews...

..and cats' are covered in barbs.

Penises are as diverse
as their owners.

Now, despite what some people say,
penises are limited in size,

even for blue whales.

So, therefore for the males
to deliver the sperm where

they need to, they need to get
close to the females.

They need to mate...

Bonking, shagging, making love...

The terminology that we
use in scientific parlance is

copulation and the reptiles weren't
the first to get at it.

Some ancient fish had been
doing it for years,

but when it came to life on land,
sex as we know it had been invented.

With their sophisticated eggs...

..and a new way to fertilise them...

..the reptiles went forth
and multiplied.

Their fossilised remains have been
found in abundance.

But world domination wasn't the only

consequence of their reproductive
success.

The egg, the penis, copulation...

All of these adaptations helped
with the mechanics of sex,

but what was to happen next
was altogether different.

You see, copulation didn't only
change the way that animals looked.

It changed the way they behaved,

and the consequences of that
were extraordinary.

Around 100 million years after
the first reptiles emerged...

..some of them have evolved
into the most legendary creatures to

have ever walked the Earth.

This is Coelophysis,

one of the first dinosaurs.

Just like his ancient ancestors, he
has strong legs for walking on land.

But like all early dinosaurs,
he walks on two instead of four.

Bigger strides allow him to cover
more distance, which is handy,

because this young male
is looking for a mate.

There are plenty of females around.

The tricky part is
getting their attention.

So how do you impress a female?

I'm probably not the best
person to answer that,

I've been struggling all of my life,

but I reckon this
guy's in with a chance.

What a magnificent animal,
so handsome, honestly!

This is a Nyala,
a Southern African antelope,

and this is a mature male,
and he's very, very impressive,

certainly from that female's
point of view.

OK, he doesn't have a sports car.

Doesn't need it,
he's got these beautiful curled,

yellow-tipped horns.

Doesn't live in a mansion.

Doesn't need that either.

He's got those broad,
powerful flanks.

And what's more,
it's not just those characteristics.

It's the fact that he's lived long
enough to be able to grow them.

I mean, imagine if this guy had been
born short-sighted or with a limp.

He would never have survived.

His good looks are visible signs
that he's fit and healthy,

and ultimately, that's what
the females are looking for.

Getting pregnant, developing
your youngster, giving birth,

then looking after it...

Those females can't afford
to bank on a weedy male.

They want the genes from the real
deal, like this guy.

When it comes to reproduction,
it tends to be the biggest,

hairiest males that succeed.

Their genes get passed down, making
future generations even bigger

and hairier than the last...

..which is how you end up
with exaggerated physical

traits like this.

But let's be very clear here,
these physical

characteristics are not necessarily
directly related to survival.

What they're about is finding
a mate, attracting that mate

and then successfully reproducing.

Evolution is not always
about survival of the fittest.

It's critically about getting
your genes into the next generation,

and that was as profoundly important
to the dinosaurs

as it is to these Nyala.

For Coelophysis,
just like the Nyala,

good looks are a sign that the male
is in good condition.

And just look at that
attractive fuzz.

But what's a male to do
if no-one seems to notice him?

Scientists suspect that some
dinosaurs did what many

animals still do today.

They show off.

It starts with head bobbing...

..followed by twirls...

..but to really impress her,
he has one final trick.

It's irresistible.

His offspring will
inherit his attractive fuzz,

and go on to have fuzzy
offspring of their own...

..becoming part of an extraordinary
evolutionary transformation.

Over time, fuzzy strands get longer,
and wider, and split into

multiple filaments, making an even
bigger surface area for display.

Until eventually,
after tens of millions of years

and countless generations...

..those fuzzy strands
are so exaggerated...

..they've become something new...

..feathers.

When the first fossilised feather
was found, scientists were

struck by its similarity to the
feathers of modern birds.

But this feather
is 150 million years old,

placing it firmly in the era
of the dinosaurs.

We don't know for certain what
drove their evolution.

Insulation and camouflage may have
played a role.

But we are now in little doubt

that some dinosaurs had feathers.

And many scientists believe it was
the need to attract a mate

that transformed dinosaurs
from scaly reptiles into flamboyant,

feathered creatures.

This is the tail feather of
a ring-necked pheasant.

It's beautiful, isn't it?

And whilst it still
serves as a tail, as you can see,

it's been given over to display.

It's elongated.

It's got this beautiful bronze
colouring with all of these

spots and when it comes to display
feathers, of course,

nothing beats the male peacock.

Look at that with that very
distinctive eye.

But this is a typical feather.
Look at it.

It's light, it's flexible,
it's durable.

It's essentially repairable.

If those barbs are pulled apart,
it can be fixed here.

But it's also symmetrical, very much

like the feathers that we first saw
when they appeared on the dinosaurs.

But tens of millions of years later,

something different cropped
up in the fossil record.

Something like this,

and you can see this is different
because it's asymmetrical.

The quill or the rachis,
if you like, here,

is much closer to this side.

Now, there is
a theory which says that this was

the result of a chance mutation,
that this was a mistake.

But if it was a mistake,
it was a very fortunate one,

because by shifting the rachis
closer to one side,

it means that when this feather
is pushed through the air,

it generates
lift like an aircraft wing.

The dinosaurs that were equipped
with these could fly.

Around 25 million years after
the first feathers evolved,

flying dinosaurs filled the skies.

Today,
we have another name for them...

..birds.

For almost 100 million years,

they thrived alongside
their giant cousins...

..and they were there to witness
one of our planet's darkest days.

EXPLOSION

When we say that
all of the dinosaurs became extinct,

it's not technically true, is it?

Because those that had
evolved into birds survived,

and the ones that did best were
the small ones,

they could hide away, and also
those with a very broad diet.

But as the Earth began to recover,
they had one other key asset,

the amniotic egg.

You see, with that embryo protected
on the inside from the hostile world

on the outside, they could continue
to reproduce, generation after

generation, to the extent that they
didn't just survive, they thrived.

The surviving birds were largely
ground dwellers.

Amongst them, the paleognaths,

some of whom would never

return to the skies.

Instead, they became big and heavy,

and better adapted for life
on the ground.

And to allow their chicks to hatch
fully formed and ready to run...

..their eggs evolved truly
gigantic sizes.

And one of this group...

..produces the largest eggs of all.

Ostriches, our largest birds.

And look at them
standing there on those strong legs,

with those sturdy bones that they
inherited from lobed-fin fishes.

And I can see those
legs are covered in scales,

so are their toes,
signs of their reptilian ancestry.

And their feathers are no longer
used for flying,

they're for display
and brooding their young.

And of course, they don't need to
return to water to lay their eggs.

These birds lay the largest
amniotic egg on the planet.

They lay them on the dry ground,

just as their reptilian
ancestors did.

And safely cocooned inside each one,

a new life begins floating in water,

just as it's always done.

These chicks are the next chapter
of an extraordinary evolutionary

story, four billion years long...

..that reveals how the ostrich

and its enormous egg came to be.

And although those
ancestors are long gone,

their legacy lives on, not just
in the ostrich...

..but in all of us.

Just like this chick, all of us
started our lives in water,

floating in that amniotic fluid in
the womb, our very own private pool.

And that's because we share an
evolutionary history with this bird.

We share ancient
ancestors in a wonderful,

unbroken chain of reproduction,
stretching back billions of years.

And of course, we're not just
connected to ostriches.

We're connected to all
life on Earth.

Everything that walks, flies,
slithers, slimes and crawls,

we're connected to it.

And that's all down to reproduction.

Over time,
sexual reproduction has shaped us

into different species...

..and sexual
reproduction has one other

absolutely extraordinary impact.

It makes us all unique.

Nothing exactly the same as me, you,

or her has ever lived,

or will ever live ever,
in the entire history

of this wonderful little blue planet
we call home.

Next time...

..how the bat evolved
one of the most

insatiable appetites
on the planet.

Look at this!

Truly spectacular!

From a prehistoric anus that
caused a mass extinction,

to gaping mouths...that became jaws.

And a surprising new
way of finding food.

This is the incredible story of one
of nature's... Oh!

..most formidable feeders.

Look at that!

But first...

..how do we know birds are living
dinosaurs?

When most people look at a bird,
they don't see a dinosaur.

The first clue of the extraordinary
evolutionary relationship

between birds and dinosaurs
came in the mid-19th century.

The Jurassic species, Archaeopteryx,
is an icon of evolution.

Archaeopteryx certainly looked
a little like a bird.

It had feathered wings,

and yet upon those wings were fully
functional three-fingered

hands with claws, which is
reptile-like, and a long tail.

It had a head like that of a bird,

and yet, inside its mouth
were rows of sharp teeth.

So, Archaeopteryx wasn't
just a bird.

It was also a dinosaur.

Other discoveries followed
that left no room for doubt.

Birds are a type of theropod
dinosaur.

We can see the evolutionary
origins of many bird

traits among their ancestors,
the dinosaurs.

Things like a beak, warm
bloodedness, feathers, a wishbone.

Tyrannosaurus rex itself
has a wishbone.

But one key question remains.

What helped birds survive
when all of their dinosaurian

relatives went extinct, for me
is one of the most fascinating

questions in all of evolutionary
biology.

A question that could have
remained unanswered

if it wasn't for a chance find.

The first time I saw this fossil,
I was not very enthusiastic.

It's basically just
a block of limestone with a couple

broken bones poking out from it.

But we decided to take a closer
look at it anyway.

A CT scanner revealed
what was hidden inside.

When I first saw that skull
on the computer screen, it took

a second of silence, and then
I realised immediately that this

was one of the most important fossil
bird specimens ever discovered.

Daniel had stumbled
across the oldest fossil of what

we would now
recognise as a modern bird.

And it lived alongside dinosaurs
just before the asteroid impact.

It is toothless like modern birds.

Its beak looks quite
a bit like a small chicken bill,

and that's interesting.

It suggests to us that this animal
was probably a generalist feeder.

That is to say it wouldn't
have been very picky,

just like living chickens.

Being flexible was critical to
surviving the asteroid impact.

One of the best ways to survive
was to simply have the

ability to eat anything.

And that might have been
one of the important features that

helped birds like this one survive
the mass extinction event.

These small chicken-like ancestors
and a few other bird species

would make sure that not all
the dinosaurs were lost.

When I see an ostrich,

I see that the... The story
of dinosaur evolution is not over.

Today there are over 10,000
species of birds.

In some ways, we are still
living in the age of dinosaurs.

Do you want to know how an elephant
is related to a clownfish?

Discover more in a poster from the
Open University on the tree of life.

To get your free copy, scan the QR
code on screen, or ring...

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