Chapter 1: A World Is Born
Hello everyone and welcome to my pseudo remake of the Walking With Series. This series will attempt to tell the story of our planet in a way that is as interesting and scientifically accurate as possible. Each episode will be dedicated to a different point in time, (Or in the case of episodes with segments times) in Earth's long and interesting history. This season in particular, will focus on life before the dinosaurs, similarly, to the original Walking With Monsters. With all that being said, let's dive right in with episode 1.
We are in what will one day be our Solar System, 4.6 billion years ago. At this time our Solar System hasn't even truly formed, being nothing but a bunch of gasses and debris floating around aimlessly, but that is all about to change. Nearby a star dies causing a massive supernova; the enormous amount of energy it produces causes the debris to contract and rotate. Gravity also begins to pull many of these materials together. Some of these materials eventually form our Sun, which itself would begin to pull in many smaller materials. The planets of our Solar System would soon begin to form from dust particles and other types of matter, one of these planets being Earth itself.
Earth's creation takes around 3 million years of time and around 4.54 billion years ago it has formed out of the dust and debris. As this process occurs the densest materials sink to the center forming the Core with other materials forming the Mantle. A thin layer of crust completes our planet and at long last our story can truly begin with a time known as the Hadean Eon. Our planet is completely unrecognizable at this time with temperatures soaring to 446 degrees fahrenheit and being covered in lava fields and molten rocks. Impacts are a frequent occurrence with asteroids frequently striking our planet's surface and the atmosphere is much denser than today. The air is made up of Methane and Carbon Dioxide toxic greenhouse gasses. Nothing can survive here.
Our planet is not alone however in the young Solar System, which is just as chaotic as the Earth itself. Many young planets battle for spots and one planet in particular is on a collision course with Earth. Meet Theia, a smaller planet around the size of Mars whose rotation around the sun notably is about to cross paths with Earth. As the planets rotate, Theia suddenly crashes into the Earth vaporizing the thin early Crust and parts of the Mantle. Theia itself ultimately loses the battle however as it is absorbed into the Earth and ultimately contributes to our abnormally sized Core.
This however isn't even Theia's greatest contribution. A chunk of Theia and our planet's Mantle that were blown out into space by the impact, begin to form into our Moon. The Moon is quickly captured by the Earth's gravitational pull, as it begins to rotate around the Earth. The Moon at this time is notably much closer to the Earth than today and this close proximity causes problems of its own. Magma is pulled from below, by the Moon's own gravitational pull bubbling up to the surface of Earth and leaving behind massive lava flows.
Also brought to the surface are copious amounts of gasses, trapped beneath the surface contributing to the hellacious conditions. Eventually the moon begins to drift away from the Earth, this process is in fact still ongoing even to this day. Surprisingly the Moon influence is still felt even today, our tides are nothing but a consequence of the Moon's own gravitational pull. Also ongoing in the Hadean is the cooling of our planet and there is another notable event happening. Asteroids continue to strike the Planets surface, this may seem like a bad thing but they actually bring something vital for life on Earth today water.
While water today would dry up in such hot conditions, the density of the atmosphere of our planet at this time ensures that the water remains in liquid form. The water at this time isn't the life-giving water of today; however it is hot and acidic in nature. Copious amounts of the acid rain falls to the planet's surface, eating away at rock formations like mountains and volcanoes. This is in fact responsible for our oceans today being salty. As the Hadean begins to come to a close and give rise to the Archean, the amount of water on Earth continues to grow, until eventually much of the planet is under water.
In the span of around 500 Million Years our planet has gone from a hellacious landscape of molten rock and magma not much different from hell to a water world. The oceans of this time are quite different from what we find today; they are hotter and deeper than any of the modern world. They are also a green color instead of the blue we see in the present. The Earth may have cooled significantly since the Hadean but at up to 185 degrees Fahrenheit it is still quite hot in spite of the sun being smaller and less bright than it is today. This is thanks to the Earth's thick atmosphere of Carbon Dioxide and Methane functioning as a blanket trapping heat from the sun.
The Earth is still very active beneath the crust, with volcanoes being pushed up, from beneath our planet's surface by plate tectonics. Some of these Volcanoes, are pushed to the surface of the water, as they begin to form islands that begin to dot the water's surface. Deep beneath the waves, meanwhile other structures are formed like hydrothermal vents. These vents are notable, for being where the water and the magma from beneath meet, forming large plumes filled with vents are notably, important for the next big step in the story of our planet's history.
Through a process called abiogenesis, some of the matter begins to come alive, the first life on Earth, has finally appeared. How this process works is still mostly unknown but the end result is small single celled organisms, who gather around the vents. The vents themselves are a perfect hotspot, for these organisms, quite literally in this case. At 212 degrees Fahrenheit, they would be scorchingly hot by today's standards, but they're perfect for these primitive creatures. The vents are also filled with valuable nutrients, which give energy to the organisms, as they feed.
As time continues to tick on, our Planet continues to be active, as massive amounts of crust is pushed to the surface of the great ocean, by the movement of tectonic plates. By about 3.4 Billion Years ago the first true continent appeared known as Vaalbara. This continent is notably made up of parts of what is now southern Africa and western Australia. While it is quite small by today's standards, it is a supercontinent in this time. The supercontinent itself will last, till about 2.7 Billion Years ago, an impressive 700 million years.
Meanwhile beneath the waves something else is going on. As time continues to march on, more and more types of organisms continue to evolve; these organisms notably evolve, to take up many different roles in the hydrothermal vents they call home, forming a complex ecosystem. This however, is starting to have consequences for life in the seas. As more species evolve, the vents are beginning to become crowded as competition for food and other resources is becoming fierce. Some organisms have an answer to this problem, however.
The primitive creatures begin to evolve and adapt as they start to move away, from the vents and to the surface. This however is a challenge in of itself, as the surface lacks nutrients however the organisms have a solution. They begin to get their energy from the sun, the first true example of photosynthesis, a system plants still use even into the present day. They quickly spread across the surface of the Earth's great ocean forming mats. Some of these mats even build upwards, forming structures called Stromatolites all the while they begin to pump out a waste gas known as Oxygen.
This sounds like a good thing, after all in today's world animals like us use Oxygen to breath, however this is not the case in the Archean. The new gas is toxic to the organisms of this time. The oxygen at first, is absorbed into the iron in the oceans causing it to break down and rust. This notably, causes the oceans to turn a blood red and this is just the beginning. As the Archean comes to an end some 2.5 billion years ago and the Proterozoic Eon begins, things are about to get much worse.
There is only so much iron actually present in the oceans and as this iron runs out the Oxygen begins to seep into the water. This slowly begins to suffocate the organisms, their own by-products and waste now dooming them. Initially the primitive Cyanobacteria, of the shallows are the main ones affected, however soon the deadly gas begins to reach the hydrothermal vents, in the depths of the seas. This quickly begins to wipe out the once thriving ecosystems here as well. This event is known as the Great Oxidation Event and it leads to death on a massive scale, the first true mass extinction.
All of this is bad enough and yet there is one final blow destined to strike the creatures that call Earth home. As the Oxygen begins to spread into the air it begins to have a reaction with the Methane already present. The loss of this greenhouse gas is absolutely devastating for the planet and it heralds the beginning of the first ice age. The Huronian Glaciation, as it is dubbed, is the final blow to life. The glaciers cover every corner of the Earth, even the equator is covered by ice.
Life now hangs in the balance, up to 99% of every living thing has been wiped out. No other mass extinction in Earth's future will match this event in scale and scope. Despite this life somehow clings on. In remote corners of the Earth, there are spots that are warmed by volcanic activity and in these spaces there are openings in the ice, allowing cyanobacteria to continue gaining energy from the sun. There are also deep hydrothermal vents that allow other organisms to survive despite the devastation.
Notably there is also hope on the horizon, after 300 million years of glaciation the planet begins to warm itself once again. The great ice sheets begin to recede and melt, freeing up unfathomable amounts of water. Soon the planet has become habitable once again and the 1% of creatures that survive are quick to take advantage of the coming bounty. Soon massive amounts of cyanobacteria begin to recolonize lost lands. That's not all, some organisms begin to further evolve and mutate.
Some organisms, rather than getting their energy from the sun, begin to get it from other organisms, forming primitive microscopic food webs. It is from this that something truly remarkable happens. Some of the organisms rather than killing the bacteria they consume, choose to keep them alive forming a symbiotic partnership with them. These are the first Eukaryotes, an important step in the story of life. Soon these Eukaryotes adapt to breathing in Oxygen and breathing out Carbon Dioxide forming, a system of checks and balances vital to life even into the present. Eukaryotes will notably begin to branch off as time goes on forming the many kingdoms of life.
Some will get energy from the sun like the Cyanobacteria becoming plants. Others will adapt to break down dead matter becoming fungi. Furthermore some will continue to feed on other organisms for their energy; these will of course become animals. These kingdoms, however, are still a long way off as are complex life in general. Still the seeds for complex life are being sown and it is likely without the Great Oxidation Event, life would have never gotten as complex as it is today.
Following the Great Oxidation Event and the Huronian Glaciation is a time in Earth's History, known as The Boring Billion. Beginning about 1.8 billion years ago, the Boring Billion sees a time of stability throughout our planet. Notably 2 supercontinents form over the course of The Boring Billion, those being Columbia and Rodinia. Columbia formed about 1.8 billion years ago and as it breaks up about 1.2 billion years ago, the continents are reorganized into Rodinia. Both of these supercontinents are made up of landmasses that make up our continents into the present day.
Meanwhile the Earth itself is quite hot at this time, with average temperatures being around 86 degrees fahrenheit. The heat is due to laughing gas in the atmosphere that traps the Sun's powerful rays. Notably Oxygen only makes up a tiny percentage of the Oxygen in the atmosphere at this time, which keeps the Earth from being cooled. Meanwhile in the great ocean things aren't much better. Hydrogen Sulfide notably fills the ocean, which is black at this time.
The ocean also has a notable stench, smelling like rotten eggs thanks to the gas. On top of all of this tropical storms and hurricanes are a frequent occurrence, thanks to the hot humid climate with winds blasting at speeds of hundreds of miles per hour. The waves from these storms often batter coastlines. All of these factors make life on Earth quite difficult during this time and yet the organisms of our planet press on. Primitive cyanobacteria and other single celled organisms remain the dominant life forms.
They are better adapted for this world, than the more advanced Eukaryotes who struggle to eke out a living in the Oxygen poor waters. The primitive organisms themselves are hunted by Protists, the apex predators of this micro world. Some of the Cyanobacteria even begin to move into fresh water and some take an even more drastic step and for the first time in Earth's history they come onto land. Eukaryotes themselves are also advancing despite their struggles. Notably some adapt to breed sexually for the first time in Earth's history.
This form of reproduction is different from the Bacteria, who breed asexually by simply duplicating. Breeding sexually requires 2 organisms, however it has the advantage of a wider amount of genetic code for the offspring. This allows Eukaryotes to adapt more quickly to their environment than bacteria who adapt far more slowly. Ironically enough The Boring Billion itself, will end up being vital to life on Earth. The relative stability of this time gives the Eukaryotes a chance to survive in a relatively stagnant time allowing them to slowly evolve and adapt allowing them to prepare for the next time in Earth's history.
That next time would soon come around 720 million years ago, a period in Earth's history would begin known as the Cryogenian. This time would see a notable event, known as Snowball Earth. Similarly to the Huronian Glaciation, which occurred a little under 2 billion years before, the entire planet is covered in ice. Even the equator is covered in a massive ice sheet with temperatures being the same here as they are in Antarctica today. The cause for this event is believed to have been massive volcanic activity.
As these volcanoes erupted, they covered the planet in a thick cloud of dust and debris, denying our planet vital sunlight, causing the temperature to drop dramatically. Soon massive ice sheets would begin to form and they would quickly begin to engulf our planet. By the time our skies clear, it was now far too late to stop the advancing wall of ice which quickly engulf our world. The ice sheets themselves notably reflect the Sun's light and keep heat from getting in, trapping our world in an icy tomb. In theory this should have massive effects on life and yet the creatures of our planet hang on.
Notably there was no significant die off, among the organisms of our planet it seems in the time since the Huronian Glaciation, the organisms that call our planet home have become better adapted to the harsh conditions a Snowball Earth has to offer. The glaciation itself lasts for millions of years, trapping our planet in its icy clutches. It seems like the ice age is destined to last for the rest of our planet's existence, however if there is one thing Earth has proven it's that nothing stays the same on its surface for long. 635 million years ago everything begins to change. Volcanic activity that started this crisis begins to help the planet escape.
The volcanoes begin to pump out massive amounts of greenhouse gasses into the air as they begin to slowly but surely heat our planet up once again. As the ice sheets melt, they signal the dawn of the final period of the Proterozoic the Ediacaran, a time which will prove vital for the rest of our planet's history. As the ice sheets melt they notably pump out nutrients into the water that allow the Cyanobacteria to thrive soon they begin photosynthesis once again. They quickly pump out Oxygen into the ocean and this time the Oxygen boom is greater than ever before. This notably allows evolution to be kickstarted once again.
Among the new arrivals are the first true animals, with creatures like the primitive sponge Otavia and this is just the beginning. While the appearance of animals is a slow process at first, by about 575 million years ago an event known as the Avalon Explosion occurs. This event notably sees a massive increase in the diversity of life. Over the next few million years, there is a notable increase in the species that occupy our primitive planet. This can be seen in particular, in what is now Australia 555 million years ago.
At this time there is notably a shallow lagoon that lies near the coast of the continent. This lagoon is notably teeming with life, fed by the variety of nutrients in the shallows. Take Charnia an immobile creature that looks almost like a leaf, yet it is not. Charnia sifts through ocean currents snatching up food passively as it floats by. It is far from the only creature out here however for there is also Tribrachidium.
Tribrachidium notably has openings in its top that help suck in water and by extension food. These creatures are notably stationary, however there are some that can actually move albeit they are rather slow by today's standards. Take Dickinsonia, a flat creature that looks like a multi segmented pancake. Dickinsonia slowly sifts through the sand absorbing food through openings in its body; it notably doesn't even have a mouth forcing it to rely on this method. Then there is the 2 inch long Spriggina, which looks almost like a soft bodied arthropod.
It is segmented much like Dickinsonia, however its head is far more obvious on its body and it notably is quite a bit faster than its much larger contemporary. The life forms of this time are truly marvelous and unlike anything alive today and yet they live on borrowed time. About 538 million years ago the Ediacaran begins to come to an end. By extension the Proterozoic, the longest of Earth's great eons, also begins to end, opening the doors for the Phanerozoic to begin the current eon of our planet.
Most of the Ediacaran creatures will not survive the transition. This seems like a bad thing and yet it actually isn't not by a long shot. The next Eon will notably see an explosion in life like no time period before one that will put even the Avalon Explosion to shame. This new world will be a very different one from the first 4 billion years, as life takes off so will the fight for survival. The creatures that inherit the Earth, will have to be tougher and more resilient than ever to survive.
Our story is far from over as a matter of fact it has only just begun.
Trivia
The opening of this episode actually went through a few revisions before I settled on the final product. I considered opening with the present day planet as a sort of prologue before having us slowly head back in time. I ultimately decided against this however as this season won't actually reach the present as it only covers the time before the dinosaurs, hence my decision to cut this opening. I also considered opening with the Big Bang, but I ultimately decided against this as I personally found it quite unnecessary.
For those wondering why I didn't mentioned the Late Orbital Bombardment, the theory has seen a bunch of scrutiny in recent years and while most aspects of this time are heavily debated with the Moon landings next year, I didn't really feel comfortable including this event as it could very well be disproven by the findings on the Moon's surface, so I reluctantly chose to ignore it.
Originally Tribrachidium wasn't going to be included but I ultimately relented and gave it a role in the episode.
Otavia is in the same boat as Tribrachidium.
This will probably be the weirdest chapter of the series as the rest will play out more like traditional Walking With Episodes.
I highly recommend the History of The Earth channel on youtube. They were a great help in the research for this chapter and they make excellent content. Give them a look if you haven't already and want to know more about "Precambrian" Earth.
That's all for this chapter folks next time everything should start getting interesting stay tuned…
