This is a story of everything that has ever happened, from the big bang to the present. Humanity has organized the deep time scales in a way that most people are not familiar with: the chronostratigraphic table of time. Our story today, will cross it from beginning to end.
It is the summary of the summary of the summary, but I hope that with this video it will be easier to understand how geological time is organized, and what events marked each period in the history of life. The idea is not to tell exactly the story of everything, but only from the perspective of some key events of the lineage that gave rise to humanity, because. .
. there is no greater theme than the story of EVERYTHING. So OBVIOUSLY I'm leaving most of it out, but hopefully I can at least get you back in geological time in a lighthearted and humorous way, because a much longer, well-explained version of this concept is coming up!
Fasten your seat belts, because this is going to be a chaotic journey, from the beginning of the universe, through the infancy of our world, the beginning of life on the continents, the age of dinosaurs and the dominance of mammals. I recommend that you activate the subtitles for a better understanding! Mainly the names.
My name is Abner and welcome to ABC Terra! Nobody knows what existed before the BIG BANG, maybe because there wasn't one before. Some assume that there are infinite dimensions, or that our universe is cyclic in some way, but science is still just scratching the surface of this problem.
Whatever there was before, our universe came into being at a certain point in time, starting from a singularity: an infinitely dense point. 13. 8 billion years ago, space and time came into being, and over time, as the universe grew and cooled during the inflationary phase, atoms of matter and antimatter arose and annihilated each other.
Fortunately, a small initial asymmetry caused a remnant of matter to remain. It is from this that stars and galaxies formed. The first stars were gigantic and died violently, creating a bunch of heavier and funnier elements out of the boring hydrogen that was there in the beginning.
Good for us, because almost every atom in our body and our planet was forged in these scandalous supernovae. That's why we are stardust, according to Carl Sagan. After a few generations of stars, the universe becomes richer in heavy elements, enough to, 9 billion years after being born, give rise to a rocky planet, made of iron and oxygen, like Earth.
We live in an increasingly metallic universe. HADEAN 4. 6 billion years ago, our planet formed from the constant collisions of larger and larger space rocks around a young star.
This is the Hadean, the infernal aeon of our world's formation. Its name comes from Hades, the god of hell in Greek mythology. This is where our table begins!
But the Earth and its companion, the Moon, did not yet properly exist. Two planets: Prototerra and Theia, fought for a very similar orbit, until one fateful day, they collided. Théia was a planet the size of Mars, and the shock made such a mess that the Earth reached its current size, and gained a ring of debris, which in a few millennia formed the Moon.
This pair orbited much closer together at first, and the sight of the Moon in the sky must have been apocalyptic, accompanied by extreme earthquakes. When the Earth begins to cool, water vapor begins to seep through its geological pores, forming a thick atmosphere, which has turned the world into a deadly sauna. As it continued to cool, this vapor condensed into downpours of biblical proportions that may have lasted for millions of years, during which Earth's oceans were formed.
At that time, the tides must have been immense, as the gravitational pull of the Moon was much stronger, but there were no continents to be destroyed by tsunamis. Tides, in the form of gigantic waves, traversed a global ocean. Oh!
And there's something alive in the ocean, but at the end of the Hadean, life was much simpler than bacteria. These early protobionts are the ancestors of all life on the planet, and his descendants will live epic stories, and learn much more than he is capable of imagining. Even because, a ball of fat involving RNA is not capable of imagining anything.
They arose in the abundant undersea chimneys that made the primeval ocean a black soup of tenebrous soot. Somehow so rotten that it created life. Literally!
ARCHAEAN 4 billion years ago, the Hadean gives way to the Archean eon. As much as this is our world, we couldn't survive here. Our planet on the first day of the Archean, 4 billion years ago, was unrecognizable.
The average temperature was 70 degrees Celsius. The atmosphere has no oxygen, it is full of methane and carbon dioxide, a suffocating gas, and even a small amount of sulfur, gave a fetid smell of carrion with rotten eggs to the whole atmosphere. These gases would make the atmosphere beige with a dark green glow.
At midday, with the sun shining at its peak, life unfolded beneath a green sky. The green of the sky was accentuated by unoxidized iron diluted in the ocean, which gave the water a characteristic green color. From space, clouds would cover nearly the entire globe, and storms of epic proportions would sweep across the entire globe nearly all the time.
The dominant sounds were of violent waves, raging winds, heavy rain and thunder. But these early Archean conditions became increasingly calm as the planet cooled. The geography starts to get more complex, as the thickening of the crust started an early type of plate tectonics, which led to the first accumulation of landmasses!
Larger and larger islands began to punctuate a global ocean Ah! And life also became more interesting. A bunch of types of bacteria and archaea, which we're going to descend from.
I know you expected more, but hey! It's already sooo much more than the Hadean protobionts offered. Now the bacteria have learned to eat the sun.
But photosynthesis was very different then. The purple bacteria secreted H2S, hydrogen sulfide. A poison to all forms of oxygenic life.
They dominated the anoxic world of the Archean, and turned the earth into a stinking, poisonous sauna for over two billion years. Eventually, there was also the form of photosynthesis we are familiar with, with oxygen as a by-product, but these were very rare and limited to oxygenated oases. But free oxygen is also extremely reactive and toxic to purple bacteria.
The war between green and purple photosynthesis continued throughout the rest of the Archean. PROTEROZOIC 2. 5 billion years ago, green bacteria finally exploded and became dominant.
This was great for us, beings who like oxygen to live, but for almost all the diversity of bacteria in the Archean, this was an unprecedented massacre. This mass extinction of purple bacteria caused by oxygen intoxication changed the world so profoundly that it ushered in a new eon: the Proterozoic. But killing just about everything that existed wasn't the only effect of oxygen, it also rusted all that free iron in the water that turned it green, turning the oceans red for a good few million years before all the oxidized iron settled out and formed the Banded Iron formations.
, or BIFS, rocks from that era that are rich in rust. As oxygen saturated the ocean and leaked into the atmosphere, everything changed. Oxygen destroyed much of the methane and sulfur gas in the atmosphere, which were the most important greenhouse gases at the time.
This made the sky bluer and less green, but it also caused temperatures to plummet uncontrollably, until the entire world was frozen in the first glaciation of the planet. This is the first snowball earth. Earth took some time to get used to the new oxygenic climate, and the fact that the Sun was weaker didn't help matters.
The beginning of the Proterozoic was marked by some glacial events and climatic instability. Eventually, some balance between greenhouse gases from volcanoes and biological and geological carbon sinks, brought the Earth out of this oppressive glaciation. The emergence of eukaryotic cells, very larger than bacteria, marked perhaps the greatest leap in complexity in the history of evolution.
If bacteria were houses, eukaryotic cells would be entire cities. They learned to live together, with bacteria inside larger cells, in a process called endosymbiosis. This gave rise to organelles such as mitochondria and chloroplast.
At that time, the beaches, without any herbivores, formed layers and layers of green biofilm, like an immense silt, which was periodically buried by the force of the tides, forming stromatolites. They are not a living being, but a biosedimentary structure, but they are a big part of our evidence for life at this time. I like to say that stromatolites are life's preferred form, the only one it has any attachment to, as some sort of stromatolites already existed at the end of the Archean, and they still exist today in Shark Bay, Australia.
So the Archean and the Proterozoic, even though they were put together as the “age of bacteria”, were very different from each other! CRYOGENIAN By the end of the Proterozoic, our type of plate tectonics was fully established, and continental formation was in full swing! All this geological activity increased erosion, and consequently, the availability of nutrients in the water, causing a burst of photosynthesis that took CO2 out of the atmosphere, reducing the Earth's greenhouse capacity and leading us to a new episode of global glaciation.
This is Cryogenian Snowball Earth. It lasts about 200 million years, with a few short breaks, but its legacy is an even more oxygenated Earth. It was only at this time that our world probably became habitable for any time traveler.
But that doesn't mean it would be comfortable, as oxygen levels would still be half of what they are today. By the end of the Cryogenian, there were oases of oxygen-rich water that were incubators of diversity for the first animals, plants, algae and multicellular fungi. But the climate was not yet stable to support bold evolutionary adventures.
EDIACARAN Arriving at the Ediacaran, the environment became more and more favorable for meso and macroscopic beings, and multicellular beings began to have fun. . .
too much. These filtering fractal goos were a good start. .
. apparently. By the way, we need to have a very serious conversation about symmetry.
But at the end of the Ediacaran, pulses of calcium in the ocean and moments of oxygenation yielded one of life's most revolutionary ideas: skeletons. Create a shell, around it, like a tube, be a tube, filter the water, but also be a shell, a skeleton, in a tube, like a shell. It gives you structure, it's great.
You get the idea. But the world of skeletal tubes like Corumbella and Cloudina, once described as the “Garden of Ediacara” in reference to the Garden of Eden, wasn't going to last long. That time, marked by an ecological simplicity and full of peaceful filter feeders that have another concept of symmetry, apparently got boring very quickly, and some unfortunate person had the brilliant idea of eating pieces of other animals, inaugurating a whole new level of the trophic chain.
I want to be a predator - said some kind of worm that left this hole in a Cloudina. Now it was war. CAMBRIAN Comes the Cambrian and now everyone has a skeleton or has learned to bury themselves!
Good, because skeletons leave much better fossils than microscopic worms and. . .
things? What life was doing until then. So much so that at that time, if you were a worm without a skeleton, it was better to bury yourself.
That's what they did, and who knew it would matter? So much important happened in the Cambrian, to the point where science simply lumps everything that happened before that into the Precambrian. Sorry stromatolites, the public likes cute animals like Opabinia!
I have five eyes Prey had increasingly strong and complex skeletons to protect themselves from predators. And the predators needed increasingly aggressive weapons and more mobility! This arms race triggered by the inauguration of the predator-prey relationship, caused an explosion of anatomical and ecological diversity among animals.
But stepping into an ocean in the Cambrian to gaze at marine life would be like a mad mushroom nightmare. Animals were trying everything, but the ancestors of all major animal phyla were already present in some form. The Cambrian's level of innovation would never again be replicated by animals.
Wow! Something exploded in the Cambrian. This is the Cambrian explosion, and what exploded was animal diversity for the first time!
Meet the new TRILOBITE! You will love this creature! It comes equipped with the big news of the moment: a calcium carbonate skeleton, but that's not all!
All sensory apparatuses are in front of the animal, because now it is moving in one direction! Isn't it amazing? This is only possible thanks to a new technology called HEAD.
But no, that's all! This little beauty comes segmented into several parts, and full of appendages that can do amazing things! Who knows all that can be done with it!
Be creative! It also comes in every size imaginable! Trilobite, right on a beach near you!
The Cambrian fauna, being the first large animal assemblage in history, has many incredible characters that are worth deepening, but that is not the proposal here. But where were we at that moment? And by us, I mean all vertebrates, from fish to amphibians, reptiles, birds and mammals.
You are a mammal. Just remembering. Meet Pikaia.
He is not the most bizarre nor the most charismatic of this fauna, but he is the animal that will give rise to the lineage that invented the spine, a definitive trait for all vertebrates. ORDOVICIAN At the end of the Cambrian, a very powerful extinction affects animal life, which is followed by a new pulse of diversification, nowhere near as large as the Cambrian explosion. But the animals update themselves, and arrive at more familiar forms.
The trilobites are still here, but now they are terrorized by huge shelled cephalopods such as Cameroceras. This is a new level of superpredator. Some of the weird Cambrian groups, like the radiodon arthropods, had their whale counterparts, like the filter-feeding giant, Aegirocassis.
Giant for the time at least. But the first fish also appear! They still don't have jaws, so they have to use weird mouths like Sacabambaspis.
But they were also using armor against predators, this will be important later. But while our history has so far been all about water, the Ordovician saw the emergence of the first land plants. At that time, they were still limited to very humid environments, such as beaches, rivers and floodplains.
These first bryophytes began the hard work: building the soil, the foundation of terrestrial ecosystems. The Ordovician ends with the first mass extinction on the planet, and the second most severe of all, eliminating more than 85% of living beings at the time. A glaciation took place, but much is discussed about terrestrial and extraterrestrial causes of this mass death event.
SILURIAN In the Silurian, further diversification after the extinction increased the share of fish in the fauna, but carnivorous sea scorpions were still a headache for the jawless fish. Until at a certain point, they learned to bite back. The emergence of jawed fish revolutionized the oceans.
They soon split between cartilaginous and bony fish, which coexisted with less derived types of fish. Some fish had the ingenious idea of having pumped-up fins. I have muscular fins!
Bombed? I meant WOBS. We'll keep an eye on those over there.
Dangerous elements. Meanwhile, on the continents, those bryophytes piled up so high that they supported giant fungi 8 meters high, like Prototaxites. The fungi's powerful enzymes process rock and dead organic matter, transforming soil from an infertile pile of dust into the living system it is today.
They were at the time the tallest living structures on the continents, but they would soon be surpassed by plants, which had just unlocked a very important skill: the transport of water and nutrients through vascular tubes. The first vascular plants appear, which reproduced with unicellular spores, and were restricted to humid environments. Its advantage was that it could reach farther from bodies of water with its roots, and grow taller with its new water transport system!
This is important, because every piece of land that gets the sun without any plants is like an empty buffet in the plant world. Some of the arthropods got tired of the unbridled bleeding that rolled in the oceans at that time and managed to make a living in the primitive continental ecosystems, not knowing that soon it would be just as crowded. DEVONIAN The Devonian arrives, known as the age of fish!
Wow, the jaw thing really caught on! The first sharks and placoderms, such as Dunkleosteus, which could reach 7 meters, took over as the most feared predators in the ocean, and that position will never go back to invertebrates. Because they don't have hands.
In a sense, modern ecosystems are established in the Devonian: In the ocean, with an age of fish that continues to this day, and on the continents, the development of the first forests. These trees are actually ferns, lycophytes and giant horsetails, which still reproduced by spores, and therefore, however much they could advance much further inland, it was nothing compared to modern plants, which manage to live even in deserts. Beneath the canopy of these first forests, terrestrial arthropods were having a feast.
The first insects diversified, along with myriapods and chelicerates. A few lobe-finned fish decided the dry land was too cool to do without. .
. these are tetrapods, which means four legs. I think this sounds familiar to you.
It took 20 million years, but these early tetrapods gave rise to the first amphibians. Which are tetrapod fish adapted for a life between water and Earth. You might think that evolution was linear and that these fish were all desperate to continue to adapt to life on the continents, but that wasn't the case.
Amphibians had everything in the water. That's where they laid their eggs and fed, and besides, the mainland was full of animals. .
. hmm. .
. uncharismatic, to say the least. Another mass extinction shakes the diversity of the Devonian, and opens the way for the Carboniferous.
Oh! And trilobites are still around. CARBONIFEROUS As the soil continued to be built by plant communities, and the warmer, wetter climate cooperated, a global forest was installed during the Carboniferous.
These plants used lignin, a very strong but malleable molecule, to build their huge, tall bodies. This molecule is great for the plant, but indigestible for bacteria and fungi. These forests had something profoundly wrong with their carbon cycle: they took carbon dioxide out of the atmosphere and put oxygen back in during life, but during death, the decomposers were unable to convert oxygen back into carbon dioxide, completing the cycle.
When these trees died, instead of completely decomposing, they were buried one on top of the other. Gradually, oxygen accumulated in the atmosphere, and carbon in the soil. All this oxygen allowed the evolution of giant arthropods, such as meganeura, which also used another novelty: flight.
Insects became the first flying animals. But the mainland was teeming with other huge arthropods, such as arthropleura. And it could have been the world of spiders, if not for a brave lineage of tetrapod fish that gave rise to land fish: amniotes.
They learned to lay eggs with shells that protected them from drying out, and from there, bye bye water! By the end of the Carboniferous, amniote fish were already divided into two factions, the sauropsida and the synapsida. The difference is the amount of holes in the skull just this time, but they still all looked like lizards.
At the end of the Carboniferous, global rainforests collapse in the first great continental extinction. They buried atmospheric carbon with their badly decomposed trunks piled up over eons, to the point of reducing the Earth's greenhouse capacity and generating a glaciation and consequent mass extinction. It was at this time that most of the fossil coal was formed, hence the name Carboniferous.
PERMIAN Pangea was fully formed, and supercontinents tend to form huge deserts at their centers. This combined with a glaciation at the South Pole, promoted an almost global desertification. But little by little, the climate became more favorable for life on the continents.
In the plant world, gymnosperms emerged, such as modern pines and araucaria, which, unlike the former pseudotrees, now used seeds, which are multicellular and resistant to periods of drought. Until then, plants used single-celled spores to reproduce, as ferns still do today. A new type of forest was emerging, better suited to animals that could tolerate dryness.
The amniote fish saw their big break at that moment! This was the first time that they played a leading role in terrestrial ecosystems, and since then, it has never ceased to be so. During the Permian, they stop looking like lizards and start exploring shapes.
. . too much.
The animals of that time were something from another world, and unfortunately the time here limits me to just saying that they should be better known. These tetrapod fish communities that inhabited Pangea during the Permian were the first true continental megafauna. They explored various aspects of herbivory, carnivory, climbing trees, swimming in rivers.
. . And surprisingly, it seemed that synapsid fish , or the ancestors of mammals, were becoming the dominant lineage.
The Permian was, in a sense, a failed first age of mammals. But paradoxically, if it had never failed, true mammals would not exist. At the end of the Permian, 252 million years ago, the most brutal mass extinction of all time wiped out more than 90% of the planet's species.
A huge lava flow in Siberia lasted thousands of years, its soot and volcanic smoke darkening the sky, suffocating plants and animals and poisoning the waters. This is called the great death, the mother of all mass extinctions. The closest animal life has ever come to simply failing.
Thus, the Paleozoic era ends, and the few survivors would inherit the entire planet and found the Mesozoic era. This time, the challenges were too tough even for the trilobites, who are living their last days at the end of the Permian. TRIASSIC The Triassic begins with the Earth scorched and the biosphere depleted.
Pangea still made climate conditions difficult for land animals, and ecosystems on continents took 20 million years to restore end-Permian diversity. Now, the roles were the same, but the actors were different. The synapsid fish, which until then dominated everything, are limited to two basic survivors: the lystrosaurus dycynodont and the trhinaxodon cynodon, let's keep an eye on that one!
Lystrosaurus is perhaps the most emblematic surviving species of the great death. They buried themselves, which may have been a key ability to traverse the Permo-Triassic passage. At the beginning of the Triassic, they had a rave, and never again did terrestrial ecosystems have such an absurd dominance of a single species.
For a while, they even diversified, grew and gave rise to Placerias, weighing one ton, but also Lisowicia, the first giant of the age of dinosaurs, weighing 7 tons! Ironic that he is a much closer relative of mammals. But it was not to last, and from the middle of the Triassic onwards, a series of bizarre reptiles came to dominate the world, the dicynodonts went to the marsh, only cynodonts were left to represent the synapsids.
The pangea was beginning to break up, and the weather was getting wetter and more pleasant. A group called archosaurs came to prevail. They gave rise to pterosaurs, crocodiles, phytosaurs, and a host of other extinct lineages, such as aetosaurs, which superficially resemble armed herbivorous crocodiles.
To exemplify the diversity of archosauromorphs in the Triassic, I want you to meet Tanystropheus, an animal with a gigantic neck associated with semi-aquatic habits. Don't you have a stick? Be the stick!
Effigia was a beaked, herbivorous, bipedal crocodile that could easily be mistaken for a dinosaur. But also Shringasaurus, the closest life has ever come to a dragon, only lacked wings. All these archosaur fish competed by occupying the different niches left by the great death.
Dinosaurs weren't necessarily dominant, but they were beginning to diversify. They were bipedal and generalist, like herrerasaurus. Or sauropodomorphs, such as Plateosaurus, which were the largest dinosaurs of the Triassic, weighing 4 tons.
The Triassic was also the end of the monopoly of fish in the oceans, when the first groups of aquatic reptiles, such as ichthyosaurs, appeared . This lineage of aquatic reptiles gave rise to the first truly giant animal: Cymbospondylus The Triassic comes to an end with yet another mass extinction, and gives way to the Jurassic. This is why Triassic animals are so strange to us, because they are caught between two mass extinctions, and they originated from the most severe one of all.
Thus, most Triassic animals lived only in the Triassic. But some of the survivors of this extinction you definitely know! JURASSIC During the Jurassic, the age of the dinosaurs is in full swing!
They were the winners of the extinction lottery, and in addition to sauropods and theropods, ornithischian dinosaurs begin to diversify. In these coniferous forests and low ferns, sauropods fed, a group of giant herbivorous dinosaurs that produced species known as diplodocus and brachiosaurus at that time. They were, at that time, the largest animals that continental ecosystems had ever produced!
The apex of gigantism in history. Other very important players* were ornithischian herbivores such as stegosaurs and theropod carnivores such as Allosaurus. This new better life condition was mainly the fault of geological changes, and consequently climatic changes caused by the rupture and fragmentation of Pangea.
With more coastal areas, moisture could reach more places, and life on continents became richer and more productive. A group of small feathered dinosaurs called Coelurosaurs gave rise to the bird lineage, the Paravian dinosaurs. But these paravian fish still didn't fly well, and yes, they used their feathers for a variety of purposes, such as thermoregulation, display, protection and to glide between one tree and another.
The small cynodonts that survived the passage into the Jurassic were also beginning to diversify into the first true mammals. It is at this time, more than 150 million years ago, that mammals are divided into lineages that would continue to lay eggs, such as monotremes, and marsupial and placental mammals, each with its own delivery and breastfeeding strategy. Despite remaining small and unable to compete in dinosaur niches, mammals were plentiful!
They were already gliding from tree to tree, like Volaticotherium, or swimming in shallow water, like castrocauda. But many of them still looked like Juramaia or Morganucodon. The Jurassic would end with a reasonably intense extinction, but dinosaur dominance prevailed, in an increasingly hotter and wetter world.
CRETACEOUS The Cretaceous was the time of the most charismatic dinosaurs! Avian coelurosaurs diversified and began to compete with pterosaurs for the skies. But another lineage of coelurosaurs grew up to become a type of supercarnivore, like Tyrannosaurus rex!
Other types of dinosaurs that appear at this time are ceratopsids, hadrosaurs and ankylosaurs. Sauropods break new size records, with the emergence of the titanosaur group, such as Patagotitan, much larger than their Jurassic ancestors! A group of pterosaurs also experiment with gigantism, the Azhdarchidae, such as Quetzalcoatlus, which gained fame as a flying giraffe.
He was the largest animal to fly in the history of the planet, with wings measuring 13 meters from tip to tip. The Cretaceous is immense, lasting about 80 million years. There is more time between the beginning and end of the Cretaceous than there is between the end of the Cretaceous and today.
Tyrannosaurus rex, for example, was one of the last non-avian dinosaurs to roam Earth. They were there when it all ended. But this species only lived in the last 2 million years of the Cretaceous, 66 million years ago.
Stegosaurus lived 100 million years before that. That is, the T rex is closer in time to us than the stegosaurus. A very important event of the Cretaceous was the emergence and diversification of angiosperms, flowering and fruiting plants.
Today, this group is 300 times more diverse than the gymnosperms that dominated until the end of the Jurassic. And who knew that a simple flower like archaefructus would change everything! They associated with insects, and they became part of the reproductive cycle of plants, in exchange for easy energy.
The Cretaceous experienced an explosion of insect diversity, especially those considered to be insect superorders. At that moment in time, the first societies began to appear , such as those that ants began to organize. They still didn't have such clear divisions of labor, and they lived in colonies of around 100 ants, but it was something unheard of.
By the end of the Cretaceous, the young Atlantic Ocean was growing, and Pangea was just a distant memory. With more fragmented continents and a high degree of active volcanism, the Cretaceous climate was much more homogeneous and the temperature was 10 degrees warmer on average than today. Forests had a global distribution, and palm fossils are found from Alaska to Antarctica, proving that these places were much more productive than they are today.
During a spring 66 million years ago, a space object 12 km in diameter hit Mexico's Yucatán Peninsula, bringing the Mesozoic to an end. PALEOGENOUS Fortunately, some lineages of reptiles, amphibians, mammals and avian dinosaurs that weighed less than 10kg survived to tell the story and usher in a whole new world. This is the Cenozoic, the era we live in until today.
It took nearly 10 million years for ecosystems to recover, and for a while, the world was relatively empty. When forest biomes were restructured, flowering plants were in the absolute majority, and a new type of forest, much denser and wetter, was established. In the beginning, the climate was getting wetter and hotter every day , and forests dominated the entire world: from the equator to the poles.
This new, warmer climate is ideal for reptiles, which produced some of the craziest predators before modern carnivores evolved. Once the dinosaurs became extinct, South America became a hot and humid tropical paradise for giant reptiles. It was here and at that time that Titanoboa lived, a gigantic constrictor boid snake, capable of eating animals the size of a horse.
Carbonemys was a giant tortoise the size of a car, which may have coexisted with Titanoboa, with a life style similar to today's snapping turtles. Huge alligator and crocodile genera such as Purusaurus have long thrived in South America. In Antarctica, which at the time was a group of islands at the south pole, the absence of predators allowed the evolution of communities of giant penguins, as tall as a person, such as Anthropornis and Palaeeudyptes!
This penguin club encompassed the entire South Pole, which is why, to this day, penguins only exist in the Southern Hemisphere. This was the closest the dinosaurs came to reconquering the planet. But throughout the rest of the world, mammals, the last representatives of the synapsid lineage, diversified and occupied the places previously occupied by dinosaurs, avenging their Permian ancestors, 200 million years later.
During this period, the Plesiadapiformes*, animals that looked like a cross between a lemur and a squirrel, appeared, and we're going to hear a lot about the descendants of this weird tree-dwelling fish. NEOGENE 23 million years ago, the neogene begins, marked by climate and environmental changes that would make the world more recognizable to the inhabitants of the present. The Indian subcontinent completely slammed into Asia, producing the largest mountain range on planet Earth.
This has increased the weathering of rocks, which are carried as sediment from rivers to the ocean, where they help fertilize photosynthesis and build shell skeletons. This, in turn, causes more carbon to be taken out of the atmosphere and buried under the ocean floor. Added to the isolation of Antarctica at the South Pole, which created a powerful ocean current, the world became much colder and drier.
Antarctica is slowly being frozen, losing its forests and becoming more inhospitable every day, until it reached the extreme climate of today, where only a few species of penguins specialized for the cold survive. The global forests have given way to a variety of biomes, most notably grassy open fields. It was in adaptation to this type of environment that the fauna of modern mammals evolved.
Hoofed animals, hoofed mammals, become the main type of herbivore, and carnivores such as dogs, cats, and bears eliminate competition from other lineages of primitive carnivores, such as creodonts. By the end of the Neogene, virtually all living animal groups are familiar and recognizable. Also in the Neogene, we have news of the first true apes.
Until then, our lineage had the face of a lemur, with a snout of a dog, but then they split into the apes of the old and new worlds. Like the rodents, they managed to reach South America and give rise to all our native apes, probably via a raft of vegetation. Among the monkeys of the old world, hominins appear, and within them, genera such as Ardipithecus, one of the first truly bipedal apes.
These hominin fish gave rise to the genus Homo, specialized in bipedal posture and with impressive manual and intellectual abilities, such as Homo habilis and Homo erectus. QUATERNARY The Quaternary period begins 2. 6 million years ago, and encompasses the Pleistocene and Holocene epochs, with the latter beginning 12,000 years ago and lasting until today.
You, and all of us, live in the Holocene Epoch, in the Quaternary Period of the Cenozoic Era in the Phanerozoic Eon. This period is marked by a deepening of the glaciation that had already begun to freeze the South Pole, now, extensive ice sheets also occur at the North Pole of the Earth. Contributing to glaciation, the tropical circulation of the Atlantic Ocean is interrupted when South America touches the north through the uplift of the Isthmus of Panama.
In the Quaternary, the North and South American faunas merged permanently, in the so-called Great American Interchange. The broad savannah conditions and the new climate stimulated and selected for gigantism among mammals, among them the most charismatic animals of the ice age megafauna, such as giant sloths and woolly mammoths. About 300 millennia ago, our species appears in East Africa, and from there, it spreads, meeting all the other 5 humanities that cohabited the planet.
50,000 years ago, there is a cognitive and cultural explosion that takes tool-making to a new level and sophisticates artistic works such as paintings, handprints and sculptures. Soon, only Homo sapiens remained alive. Between 20,000 and 10,000 years ago, much of the megafauna collapsed, depriving humanity of much of its game and forcing humans to invent inventive solutions.
10 thousand years ago, at the beginning of the Holocene, agriculture appears, and soon it spreads all over the world. This bipedal fish had just mastered domestication over plants and other fish that served to eat and work. With agriculture, populations could grow exponentially, and that's how the first cities emerged on the banks of large rivers.
The fad of civilization caught on, and the world's population slowly increased. 400 years ago, modern science, astronomy, physics and the kind of political philosophy that guide us to this day were born. With this new way of thinking about nature, technology accelerated like never before!
Soon, electricity was introduced, permanently revolutionizing the world and allowing for a whole new range of technologies and ways of life. Factories began to dominate and many products were produced quickly, it was the beginning of industrial capitalism. It is based on the burning of fossil fuels as the main source of thermal and electrical energy generation.
The coal accumulated in the Carboniferous, which was lacking during the Karoo glaciation, is now burned to satisfy the material needs of a new world. Agriculture has taken over a good part of natural ecosystems and our garbage, chemical pollutants and plastics have triggered a global mass extinction. Since then, human life has been defined by the degradation of environmental conditions and the political struggle for power, property and status.
Today, our future is defined by two major disruptive challenges: The first is the continuity of capitalism in a demographically aged economy in the contemporary age of artificial intelligence, or the knowledge economy And the second is the climate crisis itself and the environmental catastrophe that it can produce climate refugees in the billions this century, mostly in developed countries. And even with all that, lobe-finned coelacanth fish managed to survive to this day. They've been known for a long time in fossils, and they've helped apes understand that they're a super weird kind of fish.
We thought they went extinct along with non-avian dinosaurs, and even in the Cretaceous it was a living fossil 360 million years old. That's why, in 1938, they were so shocked when a fisherman simply caught one alive. In the words of the scientist who first recognized this fish in the flesh, it was more absurd than seeing a dinosaur walking down the street.
Moral of the story: you are a fish. Once inside a group, it is impossible to leave. If we want to form a biological group called “PISCES”, we have to include a common ancestor and ALL of its descendants.
When we exclude tetrapod fish from this category, it becomes artificial and has no validity in an evolutionary sense. That's why I made a point of remembering all the time that all terrestrial vertebrate creatures are still fish. There is a humbling lesson in that.
But you have to look closely at a fish to understand. You will recognize yourself. I hope that looking to the past is a way of being able to look to the future.
I like to believe that humanity is just beginning, and that the technological means that exist today will lead our species to a prosperous future compatible with the health of nature. We don't need to suffer the same fate as the dinosaurs, we now have the means to detect and deflect the orbit of a dangerous space object towards Earth. We are now unlocking the secrets of DNA editing, which could give rise to a whole new medicine.
Artificial intelligence is changing the workforce paradigm and can bring more free time and productivity to humanity than ever before. But it's up to us to produce the news of this new world, which will make all of this start to benefit us, and not destroy our jobs. Human intelligence can be a heritage not only for our species, but for the entire terrestrial biosphere.
In a way, it was the Earth that learned to defend itself and think of itself, through us. If you were interested in this video and would like to better understand the events I mentioned, I want to say that we are preparing a whole series on the history of life, much longer and more detailed. A special thanks to Lucas Mateus, the channel's art director who produced some of these amazing scenes, even with all the limitations.
Lucas does miracles with his notebook, and that slows us down a lot. To give Lucas a dignified working condition and bring more and more incredible art to the channel, we're doing a vakinha to buy him a TOP pc! The link is in the description, but the vakinha pix key is 2976959@vakinha.
com. br I can't even thank you for helping, I get emotional with every donation. Thank you for accompanying me on this journey from the beginning of time to the challenges of today, it means a lot to me.
This video tested my synthesis skills to the max and I hope you enjoyed it. Thanks even to you, uncle who will watch the video all indignant and will tell me to read the bible in the comments. I want to say that the best way to help this channel is to become a member, because it is a more fixed income than the ad revenue.
So, consider becoming a channel member, and get a little more behind the scenes of production! Thank you very much and have a great life!
