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00:00.
00:07Pegasus.
00:09Bucephalus.
00:11Champion.
00:12Trigger.
00:14Seabiscuit.
00:15Red rum.
00:16I'm talking about the stuff of myth and legend.
00:30And just look at her.
00:33She's absolutely gorgeous, aren't you?
00:38Equus ferrus caballus, the horse to you and I.
00:45A statuesque pinnacle of natural art.
00:53This is a creature supremely shaped to move.
01:17Thanks to 700 mighty muscles.
01:22And a heart the size of a football.
01:29The horse is one of the fastest and most powerful animals on the planet.
01:41They don't call it horse power for nothing.
01:48So how did the horse become one of nature's greatest athletes?
01:58To answer that.
02:02We must travel back in time.
02:10To meet the key movers and shakers.
02:13Before hooves thundered.
02:21Or hearts raced.
02:26Back to a time when almost nothing at all moved.
02:57The story of the horse.
03:00And in fact the story of the horse.
03:02The story of movement.
03:03The story of movement.
03:04Can be traced incredibly.
03:06Right to our own doorstep.
03:11The story of movement.
03:12This is a quintessential English landscape.
03:15A rural Idle of rolling hills and ancient woodlands.
03:23But I've got to tell you that if I was standing here just over half a billion years ago.
03:28The view would have been very different.
03:30In fact I wouldn't have been standing.
03:31I would have been submerged deep beneath the waves on the ocean floor.
03:35And over millions of years these rocks have been pushed up and laid bare.
03:41And they tell us of the history of that time.
03:44A history written in sand and silt.
03:46A history with some fascinating clues.
03:54Hiding in plain sight are some of the most precious fossils on the planet.
04:02But millions of years of weathering have warped these rocks.
04:07Making them very hard to spot.
04:12Now I did tell you they were tricky to see.
04:14But there is one right in front of me here.
04:18Just follow my fingers.
04:20It starts up here.
04:22Then it arches down.
04:24You can see the ridges in the rock.
04:27Particularly visible here.
04:29And then it comes up towards my shoulder.
04:31And this bit follows right up past my ear.
04:35These would have been made by fronds.
04:37And they would have been attached around a centre point.
04:40Which could have been somewhere here.
04:42This is a fossil of Brigatia.
04:45And I know it doesn't look like much.
04:47It might look like an old cabbage that's been pressed in the rock to you.
04:50But it wasn't an old cabbage.
04:52It wasn't a plant at all.
04:53And this is a very, very important fossil.
04:56Because it's a fossil of one of the earliest animals that ever lived on Earth.
05:07Over half a billion years ago, this slab of rock...
05:16..was home to some of the very first animals.
05:25Theirs is a peaceful life.
05:35But this strange community does have a problem.
05:43When animals with large, complex bodies first evolved, they couldn't move.
05:51We call them sessile.
05:57Rooted to the ground, they must rely on the ocean to bring them what they need.
06:05And they're powerless if it doesn't.
06:11Animal life could have remained stuck in this way forever.
06:16If it wasn't for an evolutionary maverick.
06:24This is a cast of a fossil that's about 565 million years old.
06:29Which means it formed around the same time as Brad Gatier.
06:33Now, when the scientists first looked at it, they were initially confused.
06:36It's quite difficult to see.
06:38Look, it starts up here and it runs down here.
06:41It's almost as if someone has been running their fingertip over some soft mud.
06:47And then it terminates down here.
06:49But if you look here, you can see there are a few little half-moon shapes.
06:54Now, the reason those scientists were initially confused is they were probably looking for a fossil of an animal.
07:00But this is not that.
07:02What it is, is a fossil of something an animal left behind.
07:09Now, we think the story goes something like this.
07:15In amongst the creatures stuck to the seabed is a tiny animal.
07:20Little more than a gelatinous blob.
07:25Like other animals here, it eats specks of food that drift on the ocean currents.
07:32But today, the current has shifted.
07:37And is now carrying the meagre morsels just out of reach.
07:45Deprived of food, the only option for this stationary population is to sit and wait for their luck and the
07:53currents to change.
07:57But this animal is a pioneer.
08:06You see, this little blob can do something that the other animals can't.
08:25Abandon the safety of its home and move.
08:30Move.
08:39With every heave, it leaves a mark.
08:47Some of the earliest animal tracks on the planet.
09:03One small step for this tiny blob.
09:06One giant leap for animal kind.
09:18Now, we'll never know exactly when the first step was taken.
09:22We can presume that there were some missteps, evolutionary stumbles, if you like.
09:27But that leap between being sessile and motile was a profound one.
09:36Today,
09:41whether they're finding food,
09:45mates,
09:47or shelter,
09:50our planet is an extravaganza of motion.
09:57An estimated 97% of animals moving in weird and wonderful ways.
10:06And none of this would be possible without one key ingredient.
10:19Muscle.
10:24To understand just how powerful muscle can be, we need a demonstration from an expert.
10:33I give you the leech.
10:39I know.
10:40Not everyone's favourite animal.
10:42But it won't surprise you to know that I'm rather a fan of the leech.
10:48What are they?
10:49Well, they're a type of worm.
10:51And there are about 700 species in the world.
10:55Many, like this one, are parasitic.
10:58This is a medicinal leech.
11:00And it's been used by medical practitioners to suck the blood from humans for three and a half thousand years.
11:07But I digress.
11:08What about its movement?
11:11Well, let's take a look at their body.
11:14First thing you'll notice, no legs.
11:16Its body is made up almost entirely of muscles.
11:27Muscles are built from tiny cells called myocytes.
11:32We sometimes call them muscle fibres.
11:37Within the leech, there are thousands.
11:41While an animal like the horse contains millions and millions of them.
11:48They work thanks to their superpower.
11:52Their ability to contract.
11:58Now this leech's muscle cells are arranged in opposing sets.
12:03There are circular muscles that run around its body and longitudinal muscles which run from one end to the other.
12:10So how exactly does it move?
12:12Well, I'll try and demonstrate that here.
12:15Come on.
12:21It stretches forward using those circular muscles.
12:25And then contracts its longitudinal muscles and pulls itself forward.
12:32So that it can slowly inch across the palm of my hand and down my fingers.
12:40Something that I find quite therapeutic.
12:46You may consider it perverse, but I'm rather enjoying this.
12:58Today, it's easy to take muscles for granted.
13:02But half a billion years ago, it was primitive muscle cells that turned contraction into action.
13:14Allowing pioneering animals to take a leap into the unknown.
13:24And the importance of this simply can't be underestimated.
13:29Because from this point on, movement would become one of the most powerful driving forces in animal evolution.
13:40To reach the next step in the story of the horse, we must hit fast forward.
13:49For the next 40 million years, evolution gallops on.
14:04Muscles stretch and shape animal life.
14:09And more and more time is spent...
14:15..on the go.
14:34They say, necessity is the mother of invention.
14:39And that was certainly the case for animals experimenting with early locomotion.
14:47Down here, every trip across the sea floor demands energy.
14:54And lots of it.
15:00And to get from A to B, it's thought that ancestors of the horse had evolved to use muscle in
15:07a totally new way.
15:10Incredibly, evidence of this can still be seen today.
15:17Inside this little plastic tub here, I have a beautiful animal.
15:25It's called a sea squirt, or a tunicate.
15:28And it's a chordate, which means we're actually related to this.
15:32I know it's difficult to believe, but it's true.
15:34And the benefit of looking at this particular species is that it's transparent.
15:40I can see inside it.
15:42And I can see a tube running around its body.
15:46And that tube is filled full of oxygen, minerals and sugar.
15:53It's its blood.
15:55And that tube is contracting.
16:00Waves of muscle contraction are pushing that blood around the body.
16:07Fundamentally, this is a simple heart.
16:12It's thought that systems like this allowed this ancestor of the horse to enjoy an active lifestyle.
16:30Just like the rest of its kind, nutrient-rich blood is being pumped through its body, making its muscles fizz
16:39with energy.
16:44Now, most of these creatures wouldn't win any races, spending their energy just wriggling along the seabed.
16:53But the ancestor of the horse seems to have had an extra boost.
17:00Meaning...
17:06It can swim harder, better, faster, stronger.
17:26NICK
17:38Its remarkable athletic ability is thanks to an innovative use of muscle
17:45that unlocked the full potential of the heart.
17:58At this point, evolution all starts to go a bit Frankenstein.
18:02You see, for any muscle to contract, it requires a stimulus, an order,
18:07and that typically comes in the form of a tiny electric zap.
18:12And it's thought that some muscle cells inside some of the earliest hearts
18:17took charge, specialised, and started to send out a series of rhythmic zaps.
18:24And all of the surrounding muscle cells complied by contracting,
18:29generating a single powerful pulse.
18:34Now, these mutant zapping cells are called pacemakers,
18:39and almost all animals have them.
18:41We have a single primary pacemaker called the sinoatrial node.
18:46And as soon as those ancient pacemakers began to pulse,
18:51they instigated a revolution.
18:57In the ancestor of the horse,
19:00those specialised pacemaker cells
19:03have now clustered together in a localised region,
19:10giving its heart a more powerful beat.
19:19And, over many generations,
19:23the beat gets stronger.
19:29The muscle walls around the pacemaker thicken.
19:36Chambers form.
19:39And valves.
19:43Directing blood flow around the body.
19:51Becoming an iconic, life-sustaining organ.
19:57It's an ingenious use of muscle.
20:01One that transformed animal locomotion.
20:06When hearts went from being a simple pump to a more complex muscular mechanism,
20:12it led to a step change in the evolution of movement.
20:16It allowed animals to become bigger, stronger, faster.
20:20It allowed them to get off of that seabed into the world above.
20:24And, from that point on, life would become a slithering, crawling, walking, running, jumping, and climbing adventure.
20:38Today, across the globe, beating hearts are pumping oxygen through all sorts of bodies.
20:48Around two and a half billion heartbeats will supply your muscles with the energy they need.
20:56From your first breath, till your last.
21:04It's a rhythm that connects us all to the first beats over half a billion years ago.
21:18Time to take a leap forward.
21:22Time to take a leap forward, as the descendants of those early swimmers get bigger, stronger, and faster.
21:30They shapeshift through countless iterations, until, 140 million years later,
21:41they have become...
21:44Fish.
21:50This is an ocean full of powerful bodies.
21:56But here, it's not how many muscles you've got that counts.
22:02It's how you use them.
22:07Now, there are many forces shaping evolution.
22:13The need to find food.
22:15The need to find mates.
22:18But there are even greater forces at play.
22:22Those forces which shape the entire universe.
22:24I'm talking about the laws of physics.
22:28And when it comes to locomotion, harnessing these would be key.
22:33And fish have achieved that with a remarkable innovation.
22:37Something that's startling in its simplicity, but significant in its importance.
22:47Something that today has helped make fish the success story of our oceans.
22:57Attached to their streamlined bodies, structures of flesh, cartilage, and bone have evolved.
23:06Tools which their muscles can control, expanding the mechanics of movement available to them.
23:18They can be gliders, thrusters, rudders.
23:24I'm talking about fins.
23:34And 380 million years ago, the ancestor of the horse was a fish with fins like this.
23:46You can see the fin here.
23:48But look at the base.
23:50It's made up of a series of robust, strong bones which anchor it to the body.
23:56And they would have been covered with powerful muscles.
23:59And it's this stalk, or lobe, which gives this group of fishes their name.
24:04We call them the lobe-finned fishes.
24:07Now, I've got to be honest with you.
24:09In the open ocean, this set-up probably didn't confer them with much of a competitive advantage.
24:15But under certain circumstances, it proved to be a real bonus.
24:29This is Onycodus, an ancient predator as big as a crocodile, with muscular-lobed fins.
24:46Now, it's size and weight should be an advantage, making Onycodus a formidable foe.
24:55But when it swims, the water around it is churned up, giving the game away.
25:10So how does this ocean giant catch its dinner?
25:20The answer lies in those lobed fins.
25:23Inside there is a tool that's just begging to be used.
25:26A tool with enormous potential.
25:29I'm talking about a lever.
25:37You see, the relatively small distance travelled by my hand and arm here
25:42is magnified out there at the tip of the oar, which is moving far further.
25:56When it comes to generating movement, muscles are fantastic.
26:00But they do have their limitations.
26:05The lever is life's great multiplier.
26:16Look, small amount of force applied by my arms in the boat is transferred to the tip of those oars,
26:24and it allows me to propel the boat forward.
26:29Not exactly with Olympic prowess, I have to confess, but with a degree of efficiency.
26:40And it's thought this same principle helped this hulking fish to move with incredible delicacy,
26:58using four of its lobed fins, along with the physics of levers,
27:05Onycodus turns minimum effort into maximum movement,
27:09and propels itself stealthily across the sea floor.
27:29Swapping swimming for walking, it saves its energy for one final powerful thrust.
27:47Thanks to its four lobed fins,
27:51Onycodus is a master of the ambush.
28:00So, with skills like these, you'd expect there to be plenty of lobed-finned fish in the sea.
28:07But today, they have almost entirely vanished from our waters.
28:19My goodness.
28:22That was a bit of a workout.
28:25Now look, levers are very useful in water,
28:28but they could become even more useful somewhere else.
28:36When fish like Onycodus begin to use their lobed fins to walk rather than swim,
28:42they set off a chain reaction.
28:52Over millions of years,
28:56the thick bridge of bones inside those four fins lengthen,
29:04and the muscles surrounding them shift and alter,
29:10creating strong, tough appendages.
29:13No longer fins at all.
29:19But four levered limbs.
29:24This was the birth of the tetrapods.
29:30And today, there are more than 30,000 species,
29:36inhabiting every continent.
29:45A diverse supergroup.
29:48All descendants of those fish with four lobed fins,
29:52are now putting them to use in very different ways.
29:58Including the horse.
30:07For many tetrapods today, moving on land is second nature.
30:12But for their ancestors crawling out of the sea,
30:16it was a very different story.
30:22Moving from one ecosystem to another,
30:25which is completely different,
30:27requires a painfully slow process of adaptation.
30:32For the creatures that were making that transition,
30:35looked a little bit like this.
30:42Oh, yes.
30:46Look at that.
30:48That's special.
30:50One of nature's jewels.
30:53Absolutely beautiful.
30:54This is a marbled newt.
30:59You can see how it got its name,
31:00with that marbling running down its back there.
31:05It's an amphibia.
31:07It spends its spring in ponds,
31:09going through its breeding cycle.
31:11And then at the end of summer,
31:12it emerges onto land where it spends the rest of the year.
31:15But of course,
31:17it's gone through millions of years of evolution,
31:20which allow it to exploit the best of both worlds,
31:23the wet and the dry.
31:26But what about its movement?
31:28Well, in the ponds,
31:29it's a fairly good swimmer, to be fair.
31:31What about on land?
31:33Let's give it a go.
31:43They're tentative.
31:45They're slow.
31:47They're laborious.
31:48They're calculated.
31:49Their little bodies bending from side to side,
31:51as they rather lethargically move through the environment.
31:57I've never seen a newt galloping or frolicking.
32:00I'm never going to.
32:01But this does tell us something very important.
32:07Movement on land is hard.
32:10Very hard.
32:18This newt can get away with having four left feet,
32:22because in a pinch,
32:25it can retreat to a habitat it finds easier to negotiate.
32:37But 350 million years ago,
32:40if the ancestors of the horse were to pursue a life solely on solid ground,
32:47they would need to be far more coordinated.
32:49And the answer to their coordination conundrum came,
32:54once again,
32:56with an evolutionary innovation from the ever-adaptable muscle.
33:02Inside almost every muscle in my body,
33:06I have something called a stretch sensor.
33:09And stretch sensors are highly specialized muscle fibers
33:13that are constantly monitoring how and when those muscles are moving.
33:19The key thing is that they are all linked together in a complex web,
33:24so each individual muscle knows exactly when every other muscle is moving.
33:32Now, despite the fact that this is an incredibly complicated system,
33:36I bet that you've never even thought about it.
33:39And that's because you don't have to,
33:41despite the fact that it's crucial for every single move that we make.
33:55Tiny stretch sensors allow the muscles to communicate with the central nervous system,
34:02giving us, and most living tetrapods,
34:04the ability to coordinate movement with astonishing precision,
34:09often faster than you can think.
34:19Look at that.
34:27Just look at the legs there.
34:29Every part of them is moving independently in isolation at the same time.
34:36And then the weight,
34:38that's got to be balanced between all four feet.
34:42And running down those legs,
34:44just going to speed it up.
34:45Look at that.
34:47Our ripples of muscles.
34:50That's the glutes,
34:51that's the quads,
34:52that's the hamstrings,
34:53all working in unison.
34:59Without these little gizmos,
35:01these stretch sensors hiding in muscles,
35:04and the complex network that joins them all together,
35:07animals with bodies like this simply would not have been able to evolve.
35:15It was down to this innovation that animal bodies could become radically more coordinated.
35:21And those tiny little bones,
35:23once hidden in those fish's fins,
35:25could really come into their own.
35:29Those fully terrestrial animals
35:32could put one foot in front of the other with extreme precision.
35:39And this was a game changer.
35:47Time for us to motor on.
35:53Over the next 300 million years,
35:56the tetrapods scattered across the earth.
36:04whilst life faced some cosmic curve balls,
36:09it was never fully derailed.
36:13And evolution carried on,
36:18tumbling us
36:24into a new world.
36:29where the way you move
36:33can be a matter of life
36:37and death.
36:44This is Phanacodus.
36:54Life looks pretty serene,
36:56but Phanacodus must constantly be on guard.
37:01Because this world is full of expert movers,
37:08whose bodies
37:11have evolved for the chase.
37:17When the hunt is on,
37:20surging adrenaline,
37:22thumping hearts,
37:23and straining muscles
37:24will only take you so far.
37:31Faced with a situation it can't muscle its way out of,
37:36the secret to Phanacodus' survival
37:40lies in its feet.
37:47Come on, Siddy.
37:48Nance, come on.
37:56Do you know sometimes people say,
37:59why poodles?
38:00Why poodles, they say.
38:02And I facetiously reply,
38:03are there other breeds of dog?
38:05I mean, look at them.
38:06Boundless energy.
38:08Incredibly loyal.
38:09And they can also help us with an important part of our story.
38:14You see, hidden beneath this curly fur here
38:17is a crucial step change in evolution.
38:21Now, I don't need to tell you about my foot and leg.
38:24You've got your own.
38:25Starts off at the toe,
38:26goes across the foot to the ankle,
38:28then you've got the shin, the knee, the thigh.
38:32We put our feet down onto the ground.
38:34We plant them flat on the ground like that.
38:38We're what we call planter grade animals.
38:40It's quite an efficient way of walking.
38:43Nancy, on the other hand, is altogether different.
38:46Let's take a look at her back leg here.
38:49You see, her toes stretch from here to here,
38:52the rest of her foot bones all the way up to here,
38:55which looks like a backward pointing knee.
38:58But this is, in fact, her ankle.
39:00Her knee is all the way up here.
39:03So Nancy is effectively standing up on her toe bones.
39:10She's a digital grade animal.
39:13And that's altogether different.
39:15It means that you move in a very different way, doesn't it?
39:18Should we show them?
39:19Come on, let's go.
39:21Come on.
39:28Come on.
39:30Right, Sid, Nancy.
39:33Let's see them in action.
39:44Look at them go.
39:45You see, this change in anatomy allows the leg to become longer,
39:50the stride to become longer,
39:52and more efficient use of all of that elastic energy stored in the muscles and tendons above their ankle.
40:00Look at that.
40:01Bouncing about.
40:05Alacrity.
40:06Agility.
40:07Critically speed.
40:10That is a happy poodle.
40:13And you know, this adaptation has occurred a number of times in terrestrial animals.
40:18But having said that, if you really want to be a creature living life in the fast lane,
40:25Evolution can offer you one more gear.
40:29Sidney Nance, come on.
40:31Come on.
40:33When it comes to speed and efficiency,
40:37Plantagrade, that's us, will get you from A to B.
40:42Digitagrade, like my dogs, ups the revs.
40:47But 56 million years ago, Phanacetus was on the verge of something new.
40:55Not just bouncing on the balls of its feet,
40:59but pushing off from the very tips of its toes.
41:08Lengthening its stride even further.
41:11So future generations take the concept and run with it.
41:22As bones elongate and muscles bulk up,
41:27they spend more and more time on tiptoe.
41:35And in the process,
41:37find the most efficiency in trading many toes
41:42for one large, powerful shock absorber.
41:52Look at this.
41:54This is clearly a cast of a fossil of a hoof.
41:59A hoof at the end of a very long leg.
42:03A leg that's clearly all about movement.
42:07A leg, though, that is surprisingly different than ours.
42:11You see essentially its foot all the way from here to here.
42:15This is the equivalent of our ankle.
42:18The bone here would be like those in the sole of our foot.
42:21And down here, it's balancing on a single tiptoe.
42:26The hoof itself would have been made of keratin,
42:29just like our fingernail.
42:31And also what's interesting is at the other end,
42:33the front legs weren't attached to the skeleton.
42:35They were embedded in a heavy mass of powerful muscle.
42:40And this gave it the capacity for a greater stride.
42:45And you see this groove here.
42:47Running down here would have been a tendon,
42:49perhaps half a metre long, a giant elastic band.
42:54But it is a leg with compromises.
42:57I mean, you can't pick anything up with a hoof.
43:00You can't manipulate anything.
43:01It's lost all dexterity at the expense of speed.
43:08This three-million-year-old hoof
43:12tells us of the arrival of a new group of animals.
43:18Animals we call Equus.
43:33These single-hoofed mammals first evolved on the plains of North America.
43:41Before spreading across the globe.
43:46Among them was one remarkable species.
43:54Equus ferrus.
43:59The horse.
44:00Known to you and I as the horse.
44:10Its body shaped generation after generation.
44:18By the evolutionary drive to move.
44:24Seven hundred muscles.
44:27Seven hundred muscles.
44:28Passed down over half a billion years
44:30from a pioneer who changed the world.
44:33A huge heart with an ancient beat
44:37that began deep beneath the waves.
44:40Long, levered limbs
44:43that once helped a fish to walk.
44:47And four large hooves.
44:50The legacy of ancestors who had to run for their lives.
44:56But there's one final twist in the story of the horse.
45:02Because Equus ferrus was about to encounter
45:07a new force of evolution.
45:16Another species on an evolutionary journey of its own.
45:21A bipedal tetrapod with opposable thumbs
45:26and an over-inflated sense of self-worth.
45:47Four thousand years ago, Homo sapiens, that's us,
45:52inhabited much of the planet.
45:55We had city-states and agriculture.
45:59Empires.
46:00We're beginning to grow.
46:04And at this time in Europe and Asia,
46:07we begin to see evidence of a growing relationship
46:11between horses and humans.
46:18Now, no-one is exactly sure how the first horse was tamed.
46:22Maybe someone caught one of those wild horses,
46:25took it into captivity, gave it shelter, food,
46:28cared for it, loved it, and trained it.
46:31But what we do know is that in pretty short time,
46:34we took these strong, efficient, powerful animals
46:39and turned them into our perfect companions.
46:43And you know, we didn't just tame them.
46:46Over generation after generation, we bred them,
46:49choosing those characteristics which favoured
46:52the way we wanted horses to be.
46:55So in the end, we took the wild horse
46:58and we turned it into the work horse.
47:13We chose the strongest.
47:17We chose the most powerful.
47:20But we also chose the friendliest, the most amenable.
47:29And for better or for worse, over the generations,
47:33the horse was altered.
47:39The ancestors of the modern horse were a pretty wild bunch.
47:44Diverse not only in terms of their physical appearance,
47:47but also their genetic makeup.
47:50About 4,000 years ago, we see two gene variants appear.
47:56Now, one of those appears to make them less aggressive,
47:59more manageable.
48:03And the other, which appears to give them a stronger back,
48:06making them easier to ride.
48:09Now, what's interesting is that within the space of just a few hundred years,
48:14we'd spread those gene variants throughout the population.
48:19The wild horse was effectively gone.
48:22We had one global species selected by humans.
48:28You.
48:30Yes.
48:30Yes.
48:31But I know.
48:32It wasn't my fault.
48:34I wasn't allowed then.
48:48Today, the horse goes by a new name.
48:54Equus Ferus Caballus.
48:57The domestic horse.
49:01Our relationship is a special one.
49:05Together, we've travelled to every corner of the globe.
49:11Step by step.
49:13And side by side.
49:21We often think of evolution as a battle between species.
49:24A game of winners and losers.
49:27A game of survival of the fittest.
49:29But very occasionally, species come together and the result is greater than the sum of their parts.
49:36Now, there's no doubt we played a hugely instrumental role in the evolution of the horse.
49:41But then the horse has had an impact on us too.
49:45Because without this remarkable animal as our greatest partner,
49:50we simply wouldn't be the species we are today.
49:58The horse's evolutionary journey is just one thread in an extraordinary tapestry.
50:07That weaves together every animal, in fact, every living thing on our planet.
50:17It's taken four billion years to get here.
50:21But boy, has life come a very, very long way.
50:29From the cell that began it all.
50:34To sex.
50:36To competition.
50:39To predation and protection.
50:48From the ocean.
50:50From the ocean to the land.
50:52And for some, back again.
50:58For others, onwards to the skies.
51:04There was a bum that changed the world.
51:08There were jaws, limbs, hearts and minds.
51:14Minds which have evolved to sense, to move, to love, to contemplate.
51:24And in our case, to begin to understand our own origins.
51:36A journey of knowledge that we're still on today.
51:44There's an outdated view, a mistaken idea, that we humans are the be-all and end-all of evolution.
51:53That everything we've explored, everything we've shown you in this series,
51:56was just about making us the perfect organism.
52:01The paragon of life on Earth.
52:04But it's simply not true.
52:07We're not perfect and we weren't made.
52:10We've been shaped by exactly the same forces that have shaped every organism that's ever lived on this planet.
52:18And through a startling twist of fate, we're now having a profound effect on evolution ourselves.
52:26A dramatic, rapid and scary one because of what we're doing to our environment.
52:32And because we're driving a massive extinction event.
52:38Now, evolution does feast on extinction.
52:43It loves the opportunities, the vacancies.
52:46So whatever we do now, life will go on.
52:50Life will be bright. Life will be beautiful. Life will be wonderful.
52:56But in evolutionary terms, what about us?
53:01Could we become shorter, slower, more short-sighted?
53:06Might we become smarter, more stupid?
53:11I don't think it really matters about our anatomy at this point.
53:16I think what matters is how we think, imagine and create our way out of our situation.
53:26I think that what needs to be driving human evolution right now is hope.
54:00How did we bring the story of evolution to life?
54:07life the way that one animal over millions of years can transform into something radically
54:13different was once a mystery lost to time if you think about the book you have lots of different
54:21pages that tell us the story from start to finish however with evolution and fossils some of those
54:27pages are missing but occasionally evidence is unearthed of the process in action in 2004
54:36paleontologists in the canadian arctic discovered a groundbreaking fossil so this is a cast of
54:44tectalic now tectalic lived about 375 million years ago and it's got the scales very much like modern
54:52day fish have today and what's quite unusual is it actually has a neck and these bones that are
54:57around there these are sort of collarbone or shoulder girdle it looks like a cross between a fish and
55:03amphibian and that's because that's exactly what it is tectalic was really this kind of unique
55:08snapshot in evolutionary time at this key moment for the water to land transition so it's a perfect
55:16example of a transitional fossil transitional fossils are incredibly rare they play the really
55:22important role of filling those gaps between morphologies that we kind of know are there but
55:27we don't really know exactly what they might have looked like transitional fossils represent just one
55:33out of millions possibly billions of individuals that over generations contribute to evolutionary change
55:41coming up with a way to illustrate this posed a huge challenge to the visual effects team behind
55:48the series evolution does not move in a straight line because it is purely opportunistic and slightly
55:55haphazard it's tinkering it's messing with what's already there rather than kind of always necessarily
56:00inventing something from scratch it's all about a great grand experiment and just seeing what happens
56:06the team spent thousands of hours crafting and animating computer-generated models to bring ancient
56:15animals back to life but to illustrate the randomness and variation seen as life evolves they needed to
56:24experiment after consulting scientists to accurately model the key evolutionary changes they used generative AI
56:32software to create hundreds of variations representing countless generations and by hand selecting and
56:41merging the best results with their original animations they were able to condense millions of years of
56:48evolution look at that there's bones inside no way into a matter of seconds in reality this would take millions
56:57of years
56:59this is a fantastic way to illustrate the evolution of form this is basically how i imagine it playing out
57:06in my head
57:17this series has been over four billion years in the making and as a certain charles darwin once wrote
57:26from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved
57:36one of the big key life lessons that i've learned from studying evolution is that change is constant
57:43and change is the norm so things have always changed and will always continue to change
57:48and life will always continue to adapt that's how it's always been and there's no reason to believe
57:56that's not how it's going to continue to be
58:10do you want to know how an elephant is related to a clownfish discover more in a poster from the
58:17open
58:17university on the tree of life to get your free copy scan the qr code on screen or ring 0
58:23300 303 3460
58:26or visit connect.open.ac.uk slash evolution
58:51you
58:52you
58:53you
59:03you
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