0:01:27 > 0:01:35The savage, rocky shores of Christmas Island, 200 miles south of Java in the Indian Ocean.
0:01:35 > 0:01:41It's November, the moon is in its third quarter and the sun is just setting.
0:01:41 > 0:01:49A few hours from now, on this very shore, a thousand million lives will be launched.
0:01:55 > 0:02:01These crabs are all females and of a kind ONLY found here.
0:02:01 > 0:02:08As darkness falls, more and more of them appear, clambering resolutely down to the sea.
0:02:08 > 0:02:11Now, it's nearing midnight.
0:02:11 > 0:02:19Their number can only be guessed, but on the island as a whole there are probably 120 million.
0:02:19 > 0:02:27And nearly all the adult females have chosen this time for their annual spawning.
0:02:42 > 0:02:47A crab like this is carrying about 100,000 eggs.
0:02:47 > 0:02:52She has to shed them directly into the sea if they are to hatch.
0:02:52 > 0:02:55But that's hazardous for her,
0:02:55 > 0:03:02because, although her ancestors came from the sea, she's a land crab and can't swim.
0:03:02 > 0:03:06A wave could sweep her away and drown her.
0:03:06 > 0:03:11But her compulsion to launch the next generation is irresistible
0:03:11 > 0:03:18and when she does reach the sea, her triumph is, apparently, ecstatic.
0:03:30 > 0:03:36The crabs have picked the moment when the tide is at its highest,
0:03:36 > 0:03:41so they have the shortest distance to travel across the beach.
0:03:41 > 0:03:46The astronomical number of eggs turns the water into a black soup.
0:03:54 > 0:03:59As dawn approaches and the tide recedes,
0:03:59 > 0:04:02the eggs are swept out to sea.
0:04:03 > 0:04:08Since life began, the sea has been full of eggs.
0:04:08 > 0:04:14The planet's most ancient animals still live and breed there.
0:04:14 > 0:04:19Some, such as sea-urchins, may be male or female.
0:04:19 > 0:04:25Both sexes discharge their sex cells during the same short period,
0:04:25 > 0:04:30so that they unite in the water and form fertile eggs.
0:04:30 > 0:04:36The sea keeps them at the stable temperature necessary to develop
0:04:36 > 0:04:41and transports them hundreds of miles to new environments.
0:04:41 > 0:04:49This perpetually-renewed soup provides a vast banquet for other floating creatures.
0:04:49 > 0:04:56Small, complex globes of jelly drive themselves through the water with lines of beating hairs
0:04:56 > 0:05:01and filter out the majority of the eggs.
0:05:34 > 0:05:41Many fish also scatter their eggs in the water and abandon them in a similar way.
0:05:41 > 0:05:46The most stupendous egg-producer of all lies beneath,
0:05:46 > 0:05:50nearly buried in the reef.
0:05:50 > 0:05:52The giant clam discharges sperm.
0:05:52 > 0:05:59Then, half an hour later, because it's both male and female, eggs.
0:05:59 > 0:06:04In each annual spasm it discharges a thousand million.
0:06:18 > 0:06:26In the north-eastern Pacific, vast shoals of herring are moving towards the coast of Alaska.
0:06:38 > 0:06:45These must be the densest concentrations of animal bodies in the world.
0:06:45 > 0:06:54They move in huge assemblies, millions strong, sieving floating food from the ocean waters.
0:06:54 > 0:06:59Now, even more tightly packed together, they start to spawn.
0:07:06 > 0:07:13Their eggs are sticky and they cover the leaves of the sea plants.
0:07:37 > 0:07:44As the waves stir the waters, some of the vast deposit floats up to the surface.
0:07:44 > 0:07:49These milky slicks, miles long, stretching around the coast,
0:07:49 > 0:07:54may look like mud, washed into the sea by a great river,
0:07:54 > 0:07:59but they are made up of nothing but eggs and milt,
0:07:59 > 0:08:04the annual legacy of the departed herring shoals.
0:08:14 > 0:08:17Many of the eggs are washed ashore,
0:08:17 > 0:08:25and the receding tide leaves them stranded on the rocks like drifts of snow.
0:08:25 > 0:08:28This provides a feast for birds.
0:08:28 > 0:08:31Gulls gorge on them.
0:08:48 > 0:08:55Thousand upon thousand of turnstones, sandpipers and other small waders also come.
0:08:55 > 0:09:02For them, this could not be better timed. They're about to set off on their spring migration
0:09:02 > 0:09:07and they need to stock up on fuel before starting their long flight.
0:09:20 > 0:09:27It is effective to lay vast numbers of eggs when water can distribute them.
0:09:27 > 0:09:36On land, such numbers would be less practical. Even so, some land animals produce them in hundreds.
0:09:36 > 0:09:38These are young mantis.
0:09:38 > 0:09:44Their mother surrounded her eggs with a liquid froth which hardened.
0:09:44 > 0:09:50The young developed within and now are ready for independent life.
0:09:50 > 0:09:55They are covered with a thin membrane
0:09:55 > 0:10:02and each hangs suspended by a thread of silk, while slowly disentangling itself.
0:10:02 > 0:10:08One egg-mass from a single female may release as many as 400 young.
0:10:16 > 0:10:20Latecomers continue to emerge,
0:10:20 > 0:10:27while the first-born clamber up over them and prepare themselves for adult life.
0:10:34 > 0:10:40Frogs produce young that swim and breathe through gills tadpoles.
0:10:40 > 0:10:45Most frogs lay their eggs in ponds and streams, but not all.
0:10:45 > 0:10:50This Trinidad tree frog creates a watery nursery up in a tree,
0:10:50 > 0:10:55where no predatory fish can worry them or their babies.
0:10:55 > 0:11:03The female pulls 2 leaves together with her hind legs and extrudes her eggs into the space between.
0:11:06 > 0:11:13The eggs are surrounded by a sticky jelly, which holds the leaves together.
0:11:13 > 0:11:22As they emerge from her body, the male on her back discharges his sperm and fertilises them.
0:11:33 > 0:11:38Over the next 8 days, the eggs slowly turn into tadpoles.
0:11:38 > 0:11:44Once the first eggs hatch, the jelly begins to dissolve.
0:11:44 > 0:11:50The leaves separate and the liquid within starts to trickle out.
0:11:50 > 0:11:54And with it come the tadpoles.
0:11:58 > 0:12:03This is no disaster. The tadpoles drop into a new existence.
0:12:03 > 0:12:09Their parents always build the nurseries overhanging water.
0:12:20 > 0:12:29Here, in a bigger world, they can find something to eat and start to build their adult bodies.
0:12:29 > 0:12:34This South American rain frog is independent of pools and rivers.
0:12:34 > 0:12:40It lays its eggs on the ground, but each globe is full of liquid.
0:12:40 > 0:12:47The tadpole develops inside this capsule and stays there, swimming in its own personal pond,
0:12:47 > 0:12:50until tadpole becomes frog.
0:13:35 > 0:13:41When the young finally emerge, they have no need to swim.
0:13:41 > 0:13:45Like their parents, they have lungs and legs.
0:13:51 > 0:13:57These elegant eggs are only the size of grains of sand.
0:14:13 > 0:14:17The young of the owl-butterfly.
0:14:20 > 0:14:25Their beautiful shells are not just protective they are edible.
0:14:25 > 0:14:31The mother butterfly built them from her bodily reserves of protein
0:14:31 > 0:14:38so that her young, when they emerge, immediately have their first meal to hand.
0:14:54 > 0:14:59There's another way to provide food for your developing young
0:14:59 > 0:15:03getting it from someone else's body.
0:15:03 > 0:15:08That involves the grisly process of body-snatching.
0:15:08 > 0:15:16That's what's going on in this dried-up mud flat in the western United States.
0:15:16 > 0:15:21This strange insect is a murderous and very hard-working wasp.
0:15:23 > 0:15:28She is digging a tunnel to serve as her nursery.
0:15:28 > 0:15:36The sun-baked ground she selects is rock-hard and digging a hole in it is not easy.
0:15:45 > 0:15:50A lot of work is invested in one of these holes
0:15:50 > 0:15:56and if one seems vacant, another wasp will try to claim it.
0:15:56 > 0:16:01Once finished, the female performs an elaborate dance around it,
0:16:01 > 0:16:09familiarising herself with its surroundings, so she knows exactly where it is.
0:16:09 > 0:16:16And then she conceals it, so that none but she is likely to find it.
0:16:21 > 0:16:29Her nursery must now be provisioned and for that she needs fresh meat
0:16:29 > 0:16:35a caterpillar. First, she paralyses it with her sting.
0:16:41 > 0:16:46Thanks to her dance, she knows exactly where her hidden hole lies.
0:16:53 > 0:16:57Each burrow will have several caterpillars in it
0:16:57 > 0:17:05and each addition requires the same stopping and unstopping of the tunnel entrance.
0:17:07 > 0:17:16The urge to collect caterpillars is so strong that they will pick them up wherever they find them.
0:17:23 > 0:17:30She has already laid a long, yellow egg on the first caterpillar.
0:17:30 > 0:17:36When the tunnel is full, she seals it with special care.
0:17:46 > 0:17:53She uses a grain of gravel like a pneumatic ram, vibrating it with her wing muscles.
0:17:53 > 0:17:58It's one of the few instances of an insect using a tool.
0:17:58 > 0:18:05In a few days, when the egg hatches, the grub will find fresh meat awaiting it.
0:18:05 > 0:18:10These cabbage white caterpillars are also doomed.
0:18:10 > 0:18:17Another species of wasp injects them, not with paralysing poison, but with eggs.
0:18:29 > 0:18:36Day after day, the caterpillars grow and mature, apparently unaffected.
0:18:36 > 0:18:40But inside them, the wasp eggs are developing.
0:19:08 > 0:19:13Having fed richly on the entrails of their caterpillar host,
0:19:13 > 0:19:21the wasp grubs are ready to pupate when they emerge. They start to spin their silken cocoons.
0:19:24 > 0:19:32Ten days later, they have become adult wasps and are themselves searching for caterpillars.
0:19:37 > 0:19:42Just where eggs are placed can be very important.
0:19:42 > 0:19:50These mosquitoes in Trinidad deposit theirs on the surface of water, where they float like rafts.
0:19:51 > 0:19:55The females signal with their legs,
0:19:55 > 0:20:03perhaps warning other flying females that this place is already taken.
0:20:03 > 0:20:12They lay in tiny pools of standing water and particularly favour nut-shells.
0:20:20 > 0:20:28Heavy raindrops might sink the tiny rafts, so if there is a shower, the adults row the eggs to shelter.
0:20:28 > 0:20:35When the young hatch, they drop from the bottom of the raft and swim down to start collecting food.
0:20:45 > 0:20:50These fish also care for their eggs with great solicitude.
0:20:50 > 0:20:54They are Midas cichlids from Nicaragua.
0:20:54 > 0:21:01Once a pair has selected their territory, the male digs a small pit in the ground.
0:21:14 > 0:21:21The golden-coloured female has meticulously cleaned a rock with her mouth.
0:21:21 > 0:21:27Now she is moving slowly over it, laying lines of sticky eggs.
0:21:28 > 0:21:36As she completes each pass, the male follows behind and discharges his sperm.
0:21:42 > 0:21:48Within an hour, there may be 2,000 fertilised eggs on the rock.
0:21:48 > 0:21:53Three days later, they begin to hatch.
0:22:02 > 0:22:07The female gently picks off the wriggling young.
0:22:12 > 0:22:19In they go, into the cradle the male dug for them even before they were spawned.
0:22:32 > 0:22:38A sticky pad on their heads lets them stick to the gravel.
0:22:38 > 0:22:47With no mouth, they are nourished from a speck of yolk within them that is bigger than they are.
0:22:47 > 0:22:52As they wriggle, they create a current that brings them oxygen.
0:22:52 > 0:22:59Their eyes are developed and much of the yolk has been used to build their bodies.
0:22:59 > 0:23:02They begin to swim.
0:23:09 > 0:23:14And all the time, their parents remain above them,
0:23:14 > 0:23:20to defend them against anything that might make a meal of them.
0:23:20 > 0:23:25Without their yolk, they must sustain themselves a different way.
0:23:25 > 0:23:30After 5 days free-swimming, they graze over their parents,
0:23:30 > 0:23:35who are producing a nutritious slime from their skins,
0:23:35 > 0:23:43so their cloud of babies can find food without straying too far away.
0:23:55 > 0:24:03Many parents put their own personal safety at risk in order to protect their eggs.
0:24:03 > 0:24:09In Brazil, a sawfly crouches over her eggs for three long weeks,
0:24:09 > 0:24:13threatening any intruder with an aggressive buzz,
0:24:13 > 0:24:20flicking her wings, with which she can strike, and displaying her formidable jaws.
0:24:20 > 0:24:26Even an assassin bug knows when it has met its match.
0:24:31 > 0:24:36As a result of her dedication, 90% of her eggs survive to hatch.
0:24:36 > 0:24:39Even then, she won't desert.
0:24:39 > 0:24:47She stays with her caterpillars to protect them, but a single guard can't be everywhere at once.
0:24:47 > 0:24:54So her young, instead of scattering to feed, remain together.
0:25:10 > 0:25:14Bigger parents have similar problems.
0:25:14 > 0:25:23Snow geese, in the Russian Arctic, have to be just as vigilant if they are to rear their babies.
0:25:26 > 0:25:33Eggs, packed with yolk, are splendid food and tempt a lot of thieves.
0:25:38 > 0:25:43For Arctic foxes, this is a time of plenty.
0:25:43 > 0:25:50Hundreds of eggs are lying around on the cold tundra, but they are all defended.
0:26:46 > 0:26:48Got one!
0:27:00 > 0:27:03But why doesn't it eat it?
0:27:09 > 0:27:12This glut of eggs won't last long.
0:27:12 > 0:27:19It's better to hide the swag for later and go back for more.
0:27:19 > 0:27:27In the cold, near-freezing earth, an egg will remain fresh and edible for a long time.
0:27:28 > 0:27:37Those in the nest are beginning the universal process that is one of life's great mysteries.
0:27:37 > 0:27:42The greater part of a bird's egg, the yolk, is food for the young.
0:27:42 > 0:27:49On its surface, beneath the cushion of clear albumen, lies just one fertile cell.
0:27:49 > 0:27:54In the sustained warmth, it grows, divides and grows again.
0:27:54 > 0:27:58Within two days, a beating heart appears.
0:27:58 > 0:28:06Blood vessels spread around the yolk, transporting nourishment to the growing embryo.
0:28:15 > 0:28:20Twelve days later, the little creature has legs.
0:28:20 > 0:28:28And beneath the tracery of blood vessels, the tiny head is virtually complete.
0:28:36 > 0:28:41Fifteen days, and feathers are beginning to sprout.
0:28:45 > 0:28:53Twenty-one days after incubation started, the moment for hatching has arrived.
0:29:37 > 0:29:42Once dried, the downy feathers help the tiny body retain warmth.
0:29:42 > 0:29:47The chick is ready to start a new stage in its life.
0:29:51 > 0:29:56There are few more formidable mothers than this one.
0:29:58 > 0:30:06The salt-water crocodile of northern Australia builds her nest on a leaf-strewn river bank.
0:30:18 > 0:30:22She digs a deep hole in the peaty soil.
0:30:26 > 0:30:31In it, she lays several dozen eggs.
0:30:33 > 0:30:38These eggs have one strange characteristic
0:30:38 > 0:30:45although they have left her body, the sex of the babies within them is not yet fixed.
0:30:45 > 0:30:50It will depend on how she looks after them.
0:30:52 > 0:30:57She covers them with dead leaves, which, as they decay,
0:30:57 > 0:31:02produce the heat the eggs need in order to develop.
0:31:05 > 0:31:11And it is this that determines the sex of the babies.
0:31:14 > 0:31:22At 30 degrees Centigrade, they will all be female. 2 degrees higher and they will be all male.
0:31:22 > 0:31:27In between, they will be exactly half and half.
0:31:27 > 0:31:352 degrees higher still and a third will be male, a third female and a third will die.
0:31:38 > 0:31:46Their emergence is not too arduous, for reptilian shells are leathery and easily broken.
0:31:55 > 0:32:03The babies are so well-formed that even before they leave the shell, they can bite.
0:32:10 > 0:32:15The technique of warming eggs with rotting leaves
0:32:15 > 0:32:20has been brought to a fine art by Australia's mallee fowl.
0:32:20 > 0:32:28A pair build themselves a huge mound of sand. In its heart lies a layer of leaves.
0:32:28 > 0:32:33Every few days, in the breeding season, the female comes to lay
0:32:33 > 0:32:38and the male kicks away sand to expose that layer.
0:32:38 > 0:32:46Her egg, compared to her body, is gigantic. As soon as she has produced it, the male covers it.
0:32:46 > 0:32:54The temperature must be carefully monitored. The male measures it with his beak.
0:32:56 > 0:33:03Even when visitors approach, he stays bravely beside the mound to keep an eye on things.
0:33:03 > 0:33:09If the mound is too cold, he piles sand on top.
0:33:09 > 0:33:12If it's too hot, he kicks it away.
0:33:13 > 0:33:18So obsessed is he with managing this mound,
0:33:18 > 0:33:24that if someone interferes with it, his first instinct is to put that right.
0:33:25 > 0:33:30If I flick sand off, he flicks it back.
0:33:57 > 0:34:02The chick has to dig its own way up through the sand.
0:34:02 > 0:34:10It can do so, because that huge egg contained enough yolk for the chick to stay inside for 49 days.
0:34:10 > 0:34:15It will be able to fly within 24 hours.
0:34:15 > 0:34:23In the trees above, there are chicks having a much harder, hungrier time.
0:34:23 > 0:34:31The crested hawk laid 3 eggs, each a day apart, but they started incubation when the first arrived.
0:34:31 > 0:34:37The first laid was the first to hatch and that chick was first fed.
0:34:37 > 0:34:46It's already bigger than the two younger ones. The parents work hard bringing food.
0:34:56 > 0:35:03But the eldest chick nearly always gets it. To him that hath, it shall be given.
0:35:06 > 0:35:15The youngest stands little chance as long as either of the bigger ones are in the least hungry.
0:35:22 > 0:35:26Once again, the youngest gets nothing.
0:35:36 > 0:35:39And now it's dead.
0:35:42 > 0:35:45This was a gamble by the adults.
0:35:45 > 0:35:52Had it been a specially good year, they would have been ready to rear three chicks,
0:35:52 > 0:35:57but this year, as in most years, the gamble didn't pay off.
0:36:06 > 0:36:12The little body is not totally wasted.
0:36:12 > 0:36:17Some of its flesh is fed to the survivors.
0:36:32 > 0:36:37Animals care for their eggs and young in many different ways,
0:36:37 > 0:36:45but Peripatus half-worm and half-centipede provides the ultimate parental protection.
0:36:45 > 0:36:51The eggs develop inside the female and she keeps them there
0:36:51 > 0:36:58until they are so advanced that they can survive without the protection of a shell.
0:37:26 > 0:37:31So the young Peripatus gets a good start in life.
0:37:32 > 0:37:37No waiting around defenceless, imprisoned in an egg.
0:37:37 > 0:37:43It's able to feed and hide itself just as soon as it leaves mother.
0:37:43 > 0:37:48All kinds of creatures have, independently, taken this strategy.
0:37:48 > 0:37:56The tsetse fly the bigger the young, the fewer a female can produce
0:37:56 > 0:38:01and the tsetse fly's baby is a whopper!
0:38:12 > 0:38:19In the whole of her six-month life, she can only give birth to a dozen of these plump grubs.
0:38:19 > 0:38:27It crawls away to turn into a pupa, from which the adult fly will quickly emerge.
0:38:27 > 0:38:32These baby beetles are also long past the egg stage.
0:38:32 > 0:38:37Their transformation into an adult will also be in a protective pupa,
0:38:37 > 0:38:42but meanwhile they work as small eating machines,
0:38:42 > 0:38:47gathering the food necessary to construct an adult body.
0:38:56 > 0:39:00These gnat grubs avoid the pupal stage altogether.
0:39:00 > 0:39:08They eat mushrooms, which disappear after a few days, so they must eat all they can, while they can.
0:39:08 > 0:39:13To do that, they reproduce even before they become adult.
0:39:13 > 0:39:18The female grub's unfertilised eggs develop inside her.
0:39:18 > 0:39:22They feed from the mother's internal organs,
0:39:22 > 0:39:27so that she is reduced by her young to a sausage skin,
0:39:27 > 0:39:34through which 30 or so grubs force their way, coming out at both ends.
0:39:34 > 0:39:39Each is a clone, genetically identical with its single parent,
0:39:39 > 0:39:44and each able to repeat this trick in six days' time.
0:39:44 > 0:39:50In six weeks, there could be 20,000 million all identical.
0:39:50 > 0:39:54A mother sea-louse a kind of crustacean
0:39:54 > 0:39:59also commits suicide to launch the next generation.
0:39:59 > 0:40:05The mass of babies in her tiny shell consume so much of her energy
0:40:05 > 0:40:11that, as the last leaves, she, exhausted, will die.
0:40:17 > 0:40:24Not only females can give birth a few exceptional males also get pregnant.
0:40:24 > 0:40:32The male pipe-fish develops a sticky underside on which the female deposits her eggs.
0:40:32 > 0:40:39Flaps of skin grow round them and, when the time comes, the young wriggle out
0:40:39 > 0:40:44to take their chances in a dangerous world.
0:41:05 > 0:41:12Once they leave the protection of their father, they are easily picked off by sticklebacks.
0:41:12 > 0:41:19But the babies who remain within their mother's body for the longest time
0:41:19 > 0:41:24and who are cared for most comprehensively are mammals.
0:41:24 > 0:41:29These female sea-lions mated a year ago.
0:41:29 > 0:41:37The fertilised egg fixed itself to the womb wall, tapped the mother's blood supply and grew for months.
0:41:37 > 0:41:45Now, that long development is over and the labour of entering the outside world has begun.
0:41:55 > 0:42:02The membranes that held fluid, within which the infant swam in its mother's body,
0:42:02 > 0:42:06still partially enclose it.
0:42:33 > 0:42:41For all mammal babies, the shock of leaving the warm, protective haven of a mother's body
0:42:41 > 0:42:48and entering the harsh, cold, danger-filled world outside, is inevitably traumatic.
0:42:53 > 0:43:00Baby antelopes, whose parents have to travel continuously to find food,
0:43:00 > 0:43:08must be as fully-developed as possible, for they must walk within hours, even though groggy.
0:43:28 > 0:43:32Chinchillas are born in the high Andes.
0:43:32 > 0:43:39Their world is a very cold one. Their mothers make no nest, so they are born fully-furred.
0:43:39 > 0:43:45Were they not, they might freeze to death.
0:44:08 > 0:44:16Hyena babies are not so advanced as they are born in a den, where their mother defends them.
0:44:16 > 0:44:23She can get rid of their bulk at an early stage of development.
0:44:23 > 0:44:31As soon as they emerge, like all young mammals, they find their mother's teat and suckle.
0:44:43 > 0:44:49Perhaps the trickiest mammal birth of all is that of the bat,
0:44:49 > 0:44:58for it, after all, has to arrive in this world while its mother hangs upside down from the ceiling.
0:44:59 > 0:45:03Whatever happens, the baby mustn't fall.
0:45:03 > 0:45:08While mother hangs from one leg, she stretches out the other,
0:45:08 > 0:45:17so that the web connecting it to the tail forms a cradle in which to catch her new-born babe.
0:45:25 > 0:45:31One infant is all that a mother bat of this species produces at once.
0:45:31 > 0:45:39Her nature makes her keep it in her body until well-developed and even one is a heavy load.
0:45:39 > 0:45:47Now she feeds it from her own body with that special food, milk, which is all the baby can digest.
0:45:47 > 0:45:52The arrival of this single baby, tenderly nurtured by its mother,
0:45:52 > 0:45:59could hardly be more different from that of so many creatures that live in the sea.
0:46:01 > 0:46:06Birth for the Christmas Island crabs is a protracted affair.
0:46:06 > 0:46:14For 28 days they float helplessly in the sea, increasing the size and complexity of their body
0:46:14 > 0:46:21until they are just recognisable as miniature crabs. But very few live as long as that.
0:46:21 > 0:46:26Fish eat them in huge quantities, currents sweep them into the ocean.
0:46:26 > 0:46:31Most years, the entire spawning of billions is totally lost.
0:46:31 > 0:46:36But, almost miraculously, about one year in five,
0:46:36 > 0:46:43a few hundred thousand appear off the coast where they fell into the water as eggs.
0:46:43 > 0:46:49Then the little, ant-size creatures valiantly struggle ashore.
0:46:49 > 0:46:53A female crab may produce a million eggs.
0:46:53 > 0:47:02If just one survives, she may be as successful as a bat, sea-lion or any other creature
0:47:02 > 0:47:07that each year lavishes its care on a single baby.
0:47:07 > 0:47:13In a multitude of different ways, new lives appear on earth,
0:47:13 > 0:47:16and each starts its own odyssey.
0:47:16 > 0:47:21They've survived their first trial, but will have to face many more
0:47:21 > 0:47:26before, in turn, they too will have a chance to give birth.