- 5/30/2025
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00:00our planet was born in fire then grew with disaster yet even then the elements of life were present
00:20water was soon present on the surface when calm it would provide a sheltered cradle for the first
00:31life on earth while the planet was born in fire it was baptized by ice for millions of years it was
00:46covered by a frozen shroud yet it seems that life not only persevered but prospered microbes evolved
00:58into a myriad creatures and one was the first to leave the oceans forever and tread on land only a
01:08few million years ago creatures that we most resemble began to walk the earth our own lives
01:15seem so fragile yet science tells us otherwise it tells us that we are but a part of the greatest
01:22journey ever made it tells us that all life is linked through time to those simple cells which
01:30drifted once in the first oceans of a miracle planet four and a half billion years ago the earth was a
01:56very different world under layers of thick gaseous clouds was a planet still hot from its birth with
02:03an atmosphere both dense and crushing
02:05bathed in filtered red light were oceans far deeper than those of today and there was one other great
02:25difference the early planet was probably only a tenth of the size that it is today but it was to grow and
02:33that chance and violent growth would prove crucial to life's history and to what we are today
02:43the early solar system was far more crowded than now where today the four inner planets orbit four and a
02:51half billion years ago were scores of smaller planets orbiting the Sun orbits of some were drawn by
02:58gravitational force towards each other and counters of awesome magnitude were unavoidable
03:03the force and heat of those collisions melted the rock but gravity would hold the two together and then
03:17weld them into one with each collision the planet would grow larger the lighter debris was cast off into
03:26space and then drawn into orbit around the enlarged planet
03:38for some millions of years the earth had rings like the planet Saturn
03:42it was chance and chance alone which made our planet larger than any of the other planets close to the Sun
03:58and somehow somewhere in this chaos life began but quite where is open to conjecture and debate
04:07here in Greenland are some of the oldest exposed rocks ever to have been found
04:15and one belt of rock four kilometers almost two miles long may take us back as far as we can go in the long history of this planet's existence
04:29Dr. Minnick Rosing of the Geological Museum of Copenhagen has visited Greenland many times in his research for evidence of Earth's early history
04:46this is a layer of fossilized carbon which he believes might be the earliest evidence of life
04:54under the microscope tiny black grains can be seen these possibly are grains of carbon the building blocks of life if so there may have been tiny microorganisms drifting in the water that were alive taking in nutrients reproducing and then dying and dropping slowly to the ocean floor when the carbon was deposited those
05:18billions of billions of years ago the thin straight lines on the rock show it was undisturbed proof that this was the bottom of a deep ocean and the thickness indicates that already life was plentiful
05:30this is not the emergence of life it cannot be because we have all this black color and that means that there was very efficient life that could make a lot of carbon and this life must have been very sophisticated so life must have been had had a long prehistory and one could speculate that probably life formed on earth maybe 4.3 billion years ago when the oceans formed and the conditions for life were present life could have emerged at that time and definitely by 3.8 billion years ago
05:48life had reached the level of sophistication that allowed it to live in the water and produce a lot of carbon so it was highly advanced life at this time
06:11for these microorganisms the prerogative was simply to survive
06:23but the challenges to life were daunting the early solar system was still a violent place
06:32a massive asteroid from outer space head straight for earth it's as large as the one that impacted over 4 billion years ago
06:40this computer simulation has been made with the scientific advice of geophysical experts to show the effects if the impact were to happen today
06:51the asteroid's diameter is larger than the main island of Japan
06:56even though it is moving at over 720,000 kilometers an hour that's almost 450,000 miles an hour
07:02the asteroid appears eerily slow because of its size
07:08the actual impact happens in the Pacific Ocean just under a thousand miles south of Japan
07:14miles south of Japan
07:45the crust of the earth is peeled away like an orange skin by what is called the crest tsunami
07:51even the deepest part of the Pacific Ocean looks like a thin film
07:54huge chunks of debris the size of city blocks are hurled into the air
08:14the entire Japanese archipelago is disintegrated as is some of the Asian continent
08:19the shattered remains are hurled out into space way beyond the atmosphere
08:30to bombard the earth with deadly intent when they re-enter
08:34at 7,000 meters 23,000 feet the rim of the crater is higher than many mountains on earth today
08:45the size of the crater would be a distance of two and a half thousand miles or four thousand kilometers
08:51and this is just the start
09:10moments after the impact
09:12rock vapor the temperature of the Sun begins to engulf the world
09:16could any life at all survive this impact
09:25immediately after the impact the rock vapor rises up from the crater in a dome
09:30then spreads out in all directions across the globe
09:37three hours after the impact south of Japan the expanding wall of vaporized rock reaches the mountains of the Himalayas
09:43the perpetual snows are instantly evaporate
09:46the perpetual snows are instantly evaporate
09:50soon the wall of fire reaches the Amazon the furthest distance from the point of impact
09:51the forest spontaneously combusts even
09:55even before the rock vapor arrives
10:10soon the wall of fire reaches the Amazon the furthest distance from the point of impact
10:15The forest spontaneously combusts even before the rock vapor arrives.
10:28Just one day after the impact, the entire planet is covered.
10:32Every living plant or creature is vaporized.
10:38The ocean would start to bubble and boil, and as the water evaporates, the oceans would
10:44drop at the rate of 5 centimeters or 2 inches every second.
10:51Even the salt deposited on the ocean floor vaporizes, and then the very bottom of the
10:55sea melts.
10:57Nothing is left untouched.
11:12One month after the impact, the surface of the world has been sterilized.
11:18The oceans have vanished.
11:20All that remains is the superheated bedrock.
11:33It is thought that an impact like this happens six times in the violent past of the Earth's
11:42history.
11:44If there was life, it was assumed that it too would have been wiped out.
11:54Only to begin again.
12:03Now science is not so certain.
12:05Now there is the strong likelihood that life, despite the odds, has survived.
12:09But how could that be possible?
12:31With the oceans gone, where could life have found a sanctuary from the searing heat?
12:43A clue to the answer was found in salt.
12:50The salt lakes in the American Southwest are the remnants of an ancient sea.
12:58Millions of years ago, in the Permian era, the upheaval of the bedrock drained the oceans
13:04and left behind these legs.
13:09Dr. Russell Vreeland is a microbiologist based at West Chester University.
13:16He's been studying the survival strategies of microbes and has come up with some remarkable
13:20results.
13:25To him, these crystals are as valuable as any gemstone.
13:29Inside the crystal are minute droplets of the seawater trapped within as the salt crystallized.
13:35A tiny hole was drilled so that the drop of water could be released.
13:45Perfectly shaped microorganisms named Bacillus permians were found, relics from the past.
13:52But the next finding was truly extraordinary.
14:01For four months, the microbes were fed with a nutrient broth.
14:05They began to divide, then multiply vigorously.
14:09After slumbering through tens of millions of years, they had come awake.
14:14Dr. Sleep of Stanford University looked long and hard at early life's survival capabilities.
14:20He thinks that he's found an answer.
14:22There was a part of the Earth where life could sustain itself, and this was deep below the
14:28ocean floor.
14:30This graph shows the temperature distribution in the subsurface of the Earth.
14:36The red area is the heat from the Earth's core.
14:39Nothing can survive in this region.
14:41Green are regions below boiling point.
14:43Blue are regions just below 50 degrees Celsius or 122 Fahrenheit.
14:50Life could survive in the blue zone.
14:52The Goldilocks zone, as Dr. Sleep calls it.
14:56However, early life needed water, and the water on the surface of the planet was gone.
15:04Was it possible to sustain any sort of life in the rocks deep below the Earth's surface?
15:15Here in South Africa, that question has been answered.
15:27This is one of the deepest man-made shafts in the world.
15:30It drops down over two miles below the surface.
15:34And it's not just the miners who take the long trip below.
15:41Dr. Esther van Heerden of South Africa's Free State University is researching the survival
15:47of life deep within the Earth.
15:54Her findings and those of the research team are astounding.
16:01Groundwater is seeping from the rocks, and the surface of the mine wall is covered by
16:20a thick film of white and black.
16:23This is a mat of various forms of bacteria, species not found on the Earth's surface.
16:29Here, they do not use oxygen.
16:34They are anaerobic.
16:36But research shows that many of them still possess the genes for oxygen respiration, useless
16:42down here.
16:44Perhaps this is evidence that these microorganisms once lived on the surface, only to migrate to
16:51these depths, perhaps to escape the heat of a total evaporation impact.
17:03To survive is life's objective, and sometime after the total evaporation event, life must
17:10have once again returned to the surface.
17:16Immediately after the impact, the planet would have looked like a fireball.
17:20But within only a year, the rock vapor would start to dissipate, and temperatures would begin
17:26to drop.
17:29Because of the Earth's size and gravity, the evaporated water would not escape into space,
17:34and within only a thousand years, the water vapor would cool and condense, and then fall
17:40back as torrential rain.
17:47Once again, the oceans would start to fill.
17:49The rainfall would be as heavy as tropical rain is today, and in only three thousand years,
18:18the oceans would have regained their original depth.
18:32The stage was set for life to return from the deep.
18:39Life on this planet had endured against all odds, from minute cracks and fissures in the
18:44bedrock.
18:46The underground life returned to the surface.
18:50Perhaps one day in the far distant future, life may once again be forced to revisit those
18:55depths.
18:59How many times this has happened, we perhaps will never know.
19:03For the next two billion years, life remained in the oceans of the world.
19:09Drifting in the waters, taking nutrients, reproducing, and dying, and living.
19:13The next challenge to life came almost two billion years ago.
19:24And if science is correct, it came not with a mighty impact, but slowly and insidiously.
19:30For millions of years at a time, the planet was shrouded with a thick covering of ice.
19:39Life endured that too, but how?
19:43It was called the Snowball Earth, and like many scientific theories, this one is hotly debated.
19:55Working with scientists at the University of Tokyo, a computer simulation was carried out to
19:59show what would happen to today's world if a Snowball Earth event were to occur.
20:12At 35 degrees north, Tokyo is just a little further south than New York.
20:17Ice up to 1,000 meters or 3,000 feet thick would bury the city.
20:24At first, any life that could not find shelter would freeze to death.
20:32At the start, the glaciers would move slowly.
20:43It would take millions of years for the ice to reach a latitude where Hawaii and Cuba are.
20:49But from there to the equator would take only a few decades.
20:57Scientists believe that if there were snowball events then, they must have persisted for millions of years.
21:04During that time, the face of the planet would have seemed a frozen and desolate wasteland,
21:09as parts of Iceland are today.
21:12There was perhaps a chance that life could survive in water beyond the oceans,
21:18living from the heat and energy that comes from the Earth itself.
21:22Iceland is known for its volcanic and thermal activity.
21:27The land has only a thin crust above the heated mantle of the planet.
21:32It sits very close to awesome power and force.
21:37Hot springs are found across the island where the heat of the Earth forces its way out.
21:43Places like these could have been a safe haven for microorganisms which like the heat.
21:50The thermophiles.
21:53And it's places like this where thermophiles can live.
22:04Where the water bubbles out, it's too hot for just about any living organism.
22:10But cooler edges are full of bacterial life.
22:15The life in these pools is made up mainly of bacteria which photosynthesize.
22:23The microbes cluster together to form thick mats.
22:29The earliest evidence of organisms like this appear before the first snowball event.
22:37The mystery yet to be solved was how the ice melted.
22:47Once a planet like the Earth was frozen, it would reflect sunlight back into space and so remain frozen.
22:53It occurred to me that a frozen surface would not influence the working of geology.
23:02And it just hit me one morning that oh, of course the carbon dioxide from volcanoes would continue to build up in the air.
23:12It was the Earth's own forces which brought the snowballs to an abrupt and dramatic finish.
23:27It's a Yarbrough.
23:46one study has suggested that when the surface of the sea reaches 45 degrees
23:59Celsius about 110 Fahrenheit it would trigger weather patterns of the world
24:05has never seen before or since
24:16the temperature differentials would cause massive hurricanes to build
24:37these hyper hurricanes would generate waves the height of buildings
24:46all this activity boosts oxygen production
25:16after the first snowball event there was little change in life
25:22after the second oxygen levels soared and the first complex life appeared expanding horizons
25:42and leading to higher and yet more complex life
25:45these strange creatures which evolved from the snowball events
25:50would not last long just a few tens of millions of years
25:56these strange creatures which evolved from the snowball events would not last long just a few tens of
26:18millions of years before a new life force took over
26:30now life could never step backwards and it was in shallow seas around a vanished continent where the
26:37next step would be taken
26:45continents move very slowly and over millions of years the changes are dramatic
26:55the earth may seem a permanent place but it is restless and responsive to the forces that surge beneath its surface
27:03the formation of continents seas and mountain ranges take millions of years but the power is awesome
27:33the mountains were forced up for over 40 million years geologists believe that some of the peaks were almost as high as Mount Everest
27:42the moisture-laden winds are halted by the peaks they rise and cool then rain falls and torrents
28:03parts of the sea were moved inland they became rivers and then where the country flattened the water spread out to become fresh water lakes
28:23new environments were created new frontiers to challenge life
28:33when the early fish moved into fresh water it was probably to escape its predators
28:40it was probably to escape its predators
28:42but they also had primitive runs and follow
28:48the
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30:11the earliest known footsteps on land are here on the west coast of Ireland this was once a swamp the foot of the Caledonian Mountains
30:20the
30:27these footprints were found in 1992 there were 260 steps made by an animal which put weight on the ground and moved its right and left feet forward alternately like reptiles walk today
30:35those first footsteps may have been at night when it was cooler and safer
30:42the first footsteps may have been at night when it was cooler and safer
30:50the
30:51the
30:57Those first footsteps may have been at night when it was cooler and safer.
31:12Once life had conquered the land, nothing seemed to be able to stop it.
31:15For almost another 100 million years, life spread across the world.
31:26And one dramatic moment in time would see the virtual extinction of all species.
31:43What happened was the greatest volcanic eruption to have ever occurred in the long history
31:48of the planet.
31:49The force of the eruption shot lava as high as 3,000 meters, almost 10,000 feet into the
32:07air.
32:08Curtains of blazing fire stretched across the horizon.
32:20Nothing living in the immediate area could have escaped.
32:39When the plants died out, they stopped producing oxygen.
32:43And methane gas released from the seabed reacted with oxygen molecules, considerably reducing
32:49the atmospheric levels.
32:54Some animals managed to survive.
32:56One of them was the creature we think is our common ancestor, Cynodont.
33:00That it survived at all is probably due to chance and luck.
33:05Yet this oxygen-depleted climate allowed a species of reptile to dominate all life on the
33:11miracle planet.
33:12There are a few fossils immediately above the boundary line drawn in the rocks.
33:25But then it changed.
33:31Plants had returned, but so had the reptiles.
33:35They had grown into giants, the dinosaurs.
33:52They spread into every available niche.
33:54There were herbivores like these massive Apatosaurus.
33:58And terrible predators like the Allosaurus.
34:22There were mammals at this time too, our ancestors, but they were of necessity small and secretive.
34:27Though very recent findings suggest that they did prey on some of the smallest of the dinosaurs.
34:35Some 65 million years ago, the mammals were still obliged to live in secrecy, still trying
34:40to stay hidden from the giant reptiles which had ruled the world for the previous 150 million years.
34:48But that rain was to come abruptly to a close.
35:13The dinosaurs were wiped out.
35:23Mammals were able to move into every niche.
35:25But it was one group that lived in the trees that began a new line in the evolutionary path.
35:31This fossil dates to about 9 million years after the dinosaurs had gone.
35:38It's called Carpalestes.
35:41There is a feature of this skeleton which is intriguing.
35:44On one of its limbs there are fingers and one of them bends toward the palm.
35:50This is what primates have today.
35:52From this fossil, we can try to reconstruct its world.
35:59Like many mammals, it was probably nocturnal.
36:09More than likely, it spent most of the time in the trees.
36:12It was safer there than on the forest floor.
36:23Its diet may have been fruit and berries.
36:26But Carpalestes' lifestyle had hardly changed since the time of dinosaurs.
36:31There were still ferocious predators on the prowl.
36:35This fossil gives the clue.
36:38The creature which made this footprint was a contemporary of Carpalestes.
36:46They belong to a bird, a giant bird called Diatrima.
36:58This reconstruction is based on the evidence gathered from the fossils.
37:01There were four species of this giant bird.
37:04They lived in forests and grasslands.
37:06But because of their weight, they were flightless.
37:09They could probably run as fast as humans today.
37:13But at this time, mammals were still mostly small and weren't able to move swiftly.
37:27The ancestor of the modern horse would not have stood a chance.
37:32Little wonder that many of the small mammals still kept to the trees.
37:55These giant birds ruled from Europe to North America.
38:02They were also on other continents in the southern hemisphere.
38:10Everywhere except Asia.
38:13Here there are no fossil birds, only mammals.
38:20The giant birds ruled their domain for another 15 or 20 million years.
38:25Their end came as a result of two things.
38:29A dramatic change in the climate.
38:31And from conflict.
38:3860 million years ago, there was a long and narrow sea,
38:41which stretched between Asia and Europe, separating the two continents.
38:45At the other end, Asia was connected to North America by a land bridge located far north and under permanent ice.
38:55Nothing could cross in or out of Asia.
38:58So in Asia, mammals began to diversify, safe from the threat of the gigantic birds.
39:10And among the mammals was a predator, smaller than the birds, but with distinct advantages.
39:16...
39:26...
39:30...
39:32...
39:37...
39:41if the oceans were the cradle for early
40:08life then Africa is the cradle for
40:11humanity climate change has had a huge
40:18impact on our evolution as the
40:22continent of Gondwana broke up India
40:25began to move north faster than the
40:27other land masses it collided with the
40:30Asian continent forcing up the
40:32mountains of the Himalayas
40:38by seven million years ago they had
40:46reached around 5,000 meters sixteen
40:49thousand feet this was when hominids
40:53began to appear in the fossil records of
40:55Africa in summer a strong up current of
40:59dry warm air rises into the sky over the
41:02Himalayas the dry air blows down to
41:06Africa from being wet and rainy all year
41:11Africa began to have distinct seasons
41:13the Sahara desert started to encroach on
41:22the forests as the forests vanished still
41:25further grasslands opened up and early
41:28humans were faced with extinction to
41:31survive they were forced to alter their
41:33lifestyle two million years ago there were
41:36at least two species of hominid living
41:38side-by-side that evidence was found in
41:42the southern tip of the African continent
41:44fossils from four million years ago to
41:47recent times are buried in layers this
41:50area has been recognized as a UNESCO world
41:53heritage site sometimes it's called the
41:57cradle of humankind dr. Francis Thackeray of the
42:01transvaal museum is an expert on early
42:04human evolution we have a remarkable
42:08deposits which are between 1.7 and 1.5
42:11million years old and in these deposits
42:15we have two species we have parent of
42:18this robustus and ape man and early homo
42:21living side-by-side over 7 million years of
42:28human evolution there have been at least 20
42:31different species except for one they
42:34have all died out
42:39moving on to the grasslands was probably
42:43forced upon early humans but they began
42:46to gain the upper hand the brain started
42:49to grow this small brain belonged to an
42:56early plant-eater in contrast this early
43:00meat-eater grew nearly twice as big while
43:03the extinct plant-eater robustus remains
43:06small the human brain consumes more
43:10energy than any other part of the body
43:12perhaps the high protein content of meat
43:15helped it to grow
43:24certainly early humans needed their brain to
43:27help them survive and to live cooperatively
43:31the human brain and brain expansion go hand
43:38in hand one supports the other if some
43:41hominin lineages had not begun to eat
43:45meat in this more significant way then we
43:49could perhaps use the example of the
43:51robust australopithecines as a as an
43:54explanation for where that might have led
43:57they became extinct by million years ago
44:01complex verbal communication allowed
44:04homo sapiens to share thoughts and
44:06ideas to cooperate in the search for food
44:09and the struggle for existence it was a
44:12struggle that the neanderthals would
44:14lose and there would be only one species
44:17left on the miracle planet we became the
44:24last survivors
44:27of the
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