A história da natureza: Do Big Bang até hoje!
الملخص
TLDRThe video takes viewers on a whirlwind journey through the history of the universe, starting from the Big Bang and moving through significant geological and biological periods on Earth. It covers the formation of Earth, the emergence of life in various forms, the age of dinosaurs, and the evolution of mammals leading to human existence. The narrative emphasizes key events such as the Cambrian explosion, mass extinctions, and the rise of Homo sapiens. It highlights the importance of reflecting on our past to navigate future challenges, particularly in light of technological advancements like DNA editing and artificial intelligence. Ultimately, it suggests that humanity is at a pivotal moment, where learning from history could shape a better future.
الوجبات الجاهزة
- 🌌 Everything began with the Big Bang 13.8 billion years ago.
- 🌍 Earth's formation occurred 4.6 billion years ago in the Hadean era.
- 🐢 The Cambrian explosion was a crucial event for animal diversity.
- 🦖 Dinosaurs ruled during the Mesozoic, ending with a mass extinction 66 million years ago.
- 🌱 The Cenozoic era witnesses the rise of mammals following the dinosaurs' extinction.
- 👣 Homo sapiens emerged around 300,000 years ago, evolving rapidly with agriculture.
- 💡 Humanity's future can benefit from technologies like DNA editing and AI.
- 🔬 Learning from past mass extinctions can guide our approach to the climate crisis.
- 🤝 Our decisions will shape the future of life on Earth.
- 🌱 Connectivity of all life demonstrates our shared ancestry as 'fish'.
الجدول الزمني
- 00:00:00 - 00:05:00
The video introduces a whimsical journey through the history of everything, from the Big Bang to the present day, focusing on key events leading to the emergence of humanity, while alluding to the vastness of geological time.
- 00:05:00 - 00:10:00
It starts from the Big Bang 13.8 billion years ago, explaining how the universe formed from a singularity, leading to the creation of stars and galaxies, and stresses the idea that we are made of stardust, as formed in supernovae.
- 00:10:00 - 00:15:00
The formation of Earth during the Hadean eon is discussed, detailing the chaotic early conditions, the collision with Theia leading to the Moon's formation, and the development of Earth's atmosphere and oceans, ultimately setting the stage for early forms of life.
- 00:15:00 - 00:20:00
In the Archean eon, Earth’s conditions were largely inhospitable with a toxic atmosphere and simple life forms predominated. The emergence of bacteria began the process of photosynthesis, significantly altering Earth's chemistry over time, setting the stage for the evolution of complex life.
- 00:20:00 - 00:25:00
The Proterozoic era marks a significant change with the dominance of green bacteria leading to the oxygenation of the atmosphere, massive geological transformations and the emergence of eukaryotic life forms, paving the way for multicellular life.
- 00:25:00 - 00:30:00
The Cryogenian period is described with severe glaciation phenomena and increasing oxygen levels, which allowed for the emergence of more complex multicellular life forms, even though ecological stability was still a challenge in this period.
- 00:30:00 - 00:35:00
Ediacaran life forms emerge with new anatomical structures like skeletons, representing a critical evolutionary development before the Cambrian explosion, which introduces rapid diversification of life and the establishment of predator-prey relationships.
- 00:35:00 - 00:42:45
The timeline culminates in the Holocene epoch where humanity faces unprecedented challenges and opportunities propelled by technology and environmental concerns, urging a harmonious future with nature based on lessons from geological history.
الخريطة الذهنية
فيديو أسئلة وأجوبة
What is the main focus of the video?
The video recounts the history of the universe and Earth's geological and biological evolution, emphasizing key events that led to humanity.
How long ago did the Big Bang occur?
The Big Bang occurred approximately 13.8 billion years ago.
What are the main eras discussed in the video?
The video covers several eras including Hadean, Archean, Proterozoic, Cambrian, Devonian, Carboniferous, Mesozoic, and Cenozoic.
What triggered the Cambrian explosion?
The Cambrian explosion was triggered by the predator-prey relationship leading to increased anatomical and ecological diversity.
What significant event marked the end of the Cretaceous period?
The Cretaceous ended with a massive asteroid impact that contributed to the extinction of non-avian dinosaurs.
How did mammals evolve after the dinosaurs?
Mammals diversified significantly after the extinction of dinosaurs, filling the ecological roles they left behind.
What defines the Quaternary period?
The Quaternary period is defined by the development of ice sheets, the rise of modern mammal groups, and the appearance of Homo sapiens.
What challenges does humanity face today according to the video?
Humanity faces challenges such as the climate crisis and the impacts of artificial intelligence on work and society.
What is the significance of DNA editing and artificial intelligence mentioned in the video?
DNA editing and artificial intelligence hold potential for advancing medicine and improving productivity, respectively.
What lesson does the video suggest about humanity's future?
The video suggests that by learning from the past, humanity can avoid the fate of dinosaurs and work towards a prosperous future.
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- 00:00:00This is a story of everything that has ever happened, from the big bang to the present.
- 00:00:11Humanity has organized the deep time scales in a way that most
- 00:00:16people are not familiar with: the chronostratigraphic table of time.
- 00:00:21Our story today, will cross it from beginning to end.
- 00:00:25It is the summary of the summary of the summary, but I hope that with this video it will be easier to understand how
- 00:00:31geological time is organized, and what events marked each period in the history of life.
- 00:00:36The idea is not to tell exactly the story of everything, but only from the perspective of
- 00:00:41some key events of the lineage that gave rise to humanity, because... there is no
- 00:00:46greater theme than the story of EVERYTHING. So OBVIOUSLY I'm leaving most of it
- 00:00:51out, but hopefully I can at least get you back in geological time in a lighthearted and
- 00:00:57humorous way, because a much longer, well-explained version of this concept is coming up!
- 00:01:02Fasten your seat belts, because this is going to be a chaotic journey, from the beginning of the universe,
- 00:01:07through the infancy of our world, the beginning of life on the continents,
- 00:01:11the age of dinosaurs and the dominance of mammals.
- 00:01:15I recommend that you activate the subtitles for a better understanding! Mainly the names.
- 00:01:20My name is Abner and welcome to ABC Terra!
- 00:01:24Nobody knows what existed before the BIG BANG, maybe because there wasn't one before.
- 00:01:39Some assume that there are infinite dimensions, or that our universe is cyclic in some way,
- 00:01:45but science is still just scratching the surface of this problem.
- 00:01:49Whatever there was before, our universe came into being at a certain point in time,
- 00:01:54starting from a singularity: an infinitely dense point.
- 00:01:5813.8 billion years ago, space and time came into being, and over time, as
- 00:02:06the universe grew and cooled during the inflationary phase, atoms of matter and
- 00:02:12antimatter arose and annihilated each other. Fortunately, a small initial asymmetry caused
- 00:02:18a remnant of matter to remain. It is from this that stars
- 00:02:22and galaxies formed. The first stars were gigantic
- 00:02:26and died violently, creating a bunch of heavier and funnier elements out of
- 00:02:31the boring hydrogen that was there in the beginning. Good for us, because almost every atom
- 00:02:36in our body and our planet was forged in these scandalous supernovae.
- 00:02:40That's why we are stardust, according to Carl Sagan.
- 00:02:44After a few generations of stars, the universe becomes richer in heavy elements,
- 00:02:48enough to, 9 billion years after being born, give rise to a rocky planet,
- 00:02:54made of iron and oxygen, like Earth. We live in an increasingly metallic universe.
- 00:03:04HADEAN 4.6 billion years ago,
- 00:03:05our planet formed from the constant collisions of larger and larger space rocks
- 00:03:11around a young star. This is the Hadean, the infernal aeon
- 00:03:16of our world's formation. Its name comes from Hades,
- 00:03:19the god of hell in Greek mythology. This is where our table begins!
- 00:03:23But the Earth and its companion, the Moon, did not yet properly exist.
- 00:03:28Two planets: Prototerra and Theia, fought for a very similar orbit,
- 00:03:34until one fateful day, they collided. Théia was a planet the size of Mars,
- 00:03:39and the shock made such a mess that the Earth reached its current size, and gained a ring of
- 00:03:45debris, which in a few millennia formed the Moon. This pair orbited much closer together at first,
- 00:03:51and the sight of the Moon in the sky must have been apocalyptic, accompanied by extreme earthquakes.
- 00:03:57When the Earth begins to cool, water vapor begins to seep through its geological pores,
- 00:04:03forming a thick atmosphere, which has turned the world into a deadly sauna.
- 00:04:07As it continued to cool, this vapor condensed into downpours of biblical proportions
- 00:04:13that may have lasted for millions of years, during which Earth's oceans were formed.
- 00:04:18At that time, the tides must have been immense, as the gravitational pull of the Moon was much stronger,
- 00:04:24but there were no continents to be destroyed by tsunamis.
- 00:04:27Tides, in the form of gigantic waves, traversed a global ocean.
- 00:04:35Oh! And there's something alive in the ocean, but at the end of the Hadean,
- 00:04:39life was much simpler than bacteria. These early protobionts are the ancestors of
- 00:04:45all life on the planet, and his descendants will live epic stories, and learn
- 00:04:51much more than he is capable of imagining. Even because, a ball of fat involving
- 00:04:55RNA is not capable of imagining anything. They arose in the abundant undersea chimneys
- 00:05:00that made the primeval ocean a black soup of tenebrous soot.
- 00:05:06Somehow so rotten that it created life. Literally!
- 00:05:12ARCHAEAN 4 billion years ago,
- 00:05:14the Hadean gives way to the Archean eon. As much as this is our world,
- 00:05:19we couldn't survive here. Our planet on the first day of the Archean,
- 00:05:234 billion years ago, was unrecognizable. The average temperature was 70 degrees Celsius.
- 00:05:30The atmosphere has no oxygen, it is full of methane and carbon dioxide, a suffocating gas,
- 00:05:36and even a small amount of sulfur, gave a fetid smell of carrion with
- 00:05:41rotten eggs to the whole atmosphere. These gases would make the atmosphere
- 00:05:45beige with a dark green glow. At midday, with the sun shining at its peak,
- 00:05:50life unfolded beneath a green sky. The green of the sky was accentuated by unoxidized iron
- 00:05:56diluted in the ocean, which gave the water a characteristic green color.
- 00:06:01From space, clouds would cover nearly the entire globe, and storms of epic proportions
- 00:06:07would sweep across the entire globe nearly all the time. The dominant sounds were of violent waves,
- 00:06:13raging winds, heavy rain and thunder. But these early Archean conditions
- 00:06:19became increasingly calm as the planet cooled.
- 00:06:23The geography starts to get more complex, as the thickening of the crust started
- 00:06:28an early type of plate tectonics, which led to the first accumulation of landmasses!
- 00:06:33Larger and larger islands began to punctuate a global ocean
- 00:06:37Ah! And life also became more interesting. A bunch of types of bacteria and archaea,
- 00:06:43which we're going to descend from. I know you expected more,
- 00:06:47but hey! It's already sooo much more than the Hadean protobionts offered.
- 00:06:52Now the bacteria have learned to eat the sun. But photosynthesis was very
- 00:06:57different then. The purple bacteria secreted H2S,
- 00:07:01hydrogen sulfide. A poison to all forms of oxygenic life.
- 00:07:05They dominated the anoxic world of the Archean, and turned the earth into a stinking, poisonous sauna
- 00:07:10for over two billion years. Eventually, there was also the form
- 00:07:15of photosynthesis we are familiar with,
- 00:07:16with oxygen as a by-product, but these were very rare and limited to oxygenated oases.
- 00:07:24But free oxygen is also extremely reactive and toxic to purple bacteria.
- 00:07:30The war between green and purple photosynthesis continued throughout the rest of the Archean.
- 00:07:36PROTEROZOIC 2.5 billion years ago,
- 00:07:40green bacteria finally exploded and became dominant.
- 00:07:43This was great for us, beings who like oxygen to live,
- 00:07:47but for almost all the diversity of bacteria in the Archean, this was an unprecedented massacre.
- 00:07:53This mass extinction of purple bacteria caused by
- 00:07:58oxygen intoxication changed the world so profoundly that it ushered in a new eon: the Proterozoic.
- 00:08:03But killing just about everything that existed wasn't the only effect of oxygen,
- 00:08:08it also rusted all that free iron in the water that turned it green, turning the oceans
- 00:08:14red for a good few million years before all the oxidized iron settled out
- 00:08:19and formed the Banded Iron formations. , or BIFS, rocks from that era that are rich in rust.
- 00:08:25As oxygen saturated the ocean and leaked into the atmosphere, everything changed.
- 00:08:30Oxygen destroyed much of the methane and sulfur gas in the atmosphere, which were
- 00:08:36the most important greenhouse gases at the time. This made the sky bluer and less
- 00:08:41green, but it also caused temperatures to plummet uncontrollably, until the entire world was
- 00:08:47frozen in the first glaciation of the planet. This is the first snowball earth.
- 00:08:53Earth took some time to get used to the new oxygenic climate, and the fact that
- 00:08:58the Sun was weaker didn't help matters. The beginning of the Proterozoic was marked by some
- 00:09:04glacial events and climatic instability. Eventually, some balance between
- 00:09:09greenhouse gases from volcanoes and biological and geological carbon sinks,
- 00:09:13brought the Earth out of this oppressive glaciation. The emergence of eukaryotic cells, very
- 00:09:19larger than bacteria, marked perhaps the greatest leap in complexity in the history of evolution.
- 00:09:24If bacteria were houses, eukaryotic cells would be entire cities.
- 00:09:29They learned to live together, with bacteria inside larger cells,
- 00:09:34in a process called endosymbiosis. This gave rise to organelles
- 00:09:38such as mitochondria and chloroplast. At that time, the beaches, without any herbivores,
- 00:09:43formed layers and layers of green biofilm, like an immense silt, which was
- 00:09:49periodically buried by the force of the tides, forming stromatolites. They are not a living being, but a
- 00:09:55biosedimentary structure, but they are a big part of our evidence for life at this time.
- 00:09:59I like to say that stromatolites are life's preferred form, the only one it has any attachment to,
- 00:10:05as some sort of stromatolites already existed at the end of the Archean, and they
- 00:10:09still exist today in Shark Bay, Australia. So the Archean and the Proterozoic,
- 00:10:14even though they were put together as the “age of bacteria”, were very different from each other!
- 00:10:21CRYOGENIAN By the end of the Proterozoic,
- 00:10:23our type of plate tectonics was fully established,
- 00:10:27and continental formation was in full swing! All this geological activity increased erosion,
- 00:10:34and consequently, the availability of nutrients in the water, causing a burst of
- 00:10:39photosynthesis that took CO2 out of the atmosphere, reducing the Earth's greenhouse capacity and
- 00:10:45leading us to a new episode of global glaciation. This is Cryogenian Snowball Earth.
- 00:10:51It lasts about 200 million years, with a few short breaks, but its legacy
- 00:10:55is an even more oxygenated Earth. It was only at this time that
- 00:11:00our world probably became habitable for any time traveler.
- 00:11:03But that doesn't mean it would be comfortable, as oxygen levels would still be half of what they are today.
- 00:11:09By the end of the Cryogenian, there were oases of oxygen-rich water that were incubators
- 00:11:15of diversity for the first animals, plants, algae and multicellular fungi.
- 00:11:19But the climate was not yet stable to support bold evolutionary adventures.
- 00:11:25EDIACARAN Arriving at the Ediacaran,
- 00:11:28the environment became more and more favorable for meso and macroscopic beings, and multicellular beings
- 00:11:35began to have fun... too much. These filtering fractal goos were a good
- 00:11:41start... apparently. By the way, we need to have
- 00:11:45a very serious conversation about symmetry. But at the end of the Ediacaran, pulses of calcium in the
- 00:11:50ocean and moments of oxygenation yielded one of life's most revolutionary ideas: skeletons.
- 00:11:57Create a shell, around it, like a tube, be a tube, filter the water, but also be a shell,
- 00:12:04a skeleton, in a tube, like a shell. It gives you structure, it's great. You get the idea.
- 00:12:10But the world of skeletal tubes like Corumbella and Cloudina, once described
- 00:12:15as the “Garden of Ediacara” in reference to the Garden of Eden, wasn't going to last long.
- 00:12:19That time, marked by an ecological simplicity and full of peaceful filter feeders
- 00:12:25that have another concept of symmetry, apparently got boring very quickly,
- 00:12:30and some unfortunate person had the brilliant idea of eating pieces of other animals, inaugurating
- 00:12:36a whole new level of the trophic chain. I want to be
- 00:12:41a predator - said some kind of worm that left this
- 00:12:45hole in a Cloudina. Now it was war.
- 00:12:50CAMBRIAN Comes the Cambrian and now everyone
- 00:12:52has a skeleton or has learned to bury themselves! Good, because skeletons leave much
- 00:12:58better fossils than microscopic worms and... things? What life was doing until then.
- 00:13:03So much so that at that time, if you were a worm without a skeleton, it was better to bury yourself.
- 00:13:07That's what they did, and who knew it would matter?
- 00:13:10So much important happened in the Cambrian, to the point where science simply lumps everything
- 00:13:16that happened before that into the Precambrian. Sorry stromatolites, the public likes
- 00:13:21cute animals like Opabinia! I have five eyes
- 00:13:25Prey had increasingly strong and complex skeletons to protect themselves from predators.
- 00:13:30And the predators needed increasingly aggressive weapons and more mobility!
- 00:13:35This arms race triggered by the inauguration of the predator-prey relationship,
- 00:13:39caused an explosion of anatomical and ecological diversity among animals.
- 00:13:44But stepping into an ocean in the Cambrian to gaze at marine life would be
- 00:13:48like a mad mushroom nightmare. Animals were trying everything,
- 00:13:53but the ancestors of all major animal phyla were already present in some form.
- 00:13:58The Cambrian's level of innovation would never again be replicated by animals.
- 00:14:02Wow! Something exploded in the Cambrian. This is the Cambrian explosion, and what exploded was
- 00:14:08animal diversity for the first time! Meet the new TRILOBITE! You will
- 00:14:13love this creature! It comes equipped with
- 00:14:16the big news of the moment: a calcium carbonate skeleton, but that's not all!
- 00:14:21All sensory apparatuses are in front of the animal,
- 00:14:24because now it is moving in one direction! Isn't it amazing? This is only possible thanks to
- 00:14:29a new technology called HEAD. But no, that's all! This little beauty
- 00:14:35comes segmented into several parts, and full of appendages that can do amazing things!
- 00:14:39Who knows all that can be done with it! Be creative!
- 00:14:42It also comes in every size imaginable!
- 00:14:46Trilobite, right on a beach near you! The Cambrian fauna, being the first large
- 00:14:52animal assemblage in history, has many incredible characters that are worth
- 00:14:56deepening, but that is not the proposal here. But where were we at that moment? And by us,
- 00:15:01I mean all vertebrates, from fish to amphibians, reptiles, birds and mammals.
- 00:15:06You are a mammal. Just remembering. Meet Pikaia.
- 00:15:10He is not the most bizarre nor the most charismatic of this fauna, but he is the animal that will give rise to the
- 00:15:15lineage that invented the spine, a definitive trait for all vertebrates.
- 00:15:19ORDOVICIAN At the end of the Cambrian, a very powerful extinction
- 00:15:23affects animal life, which is followed by a new pulse of diversification, nowhere near
- 00:15:28as large as the Cambrian explosion. But the animals update themselves,
- 00:15:30and arrive at more familiar forms. The trilobites are still here,
- 00:15:34but now they are terrorized by huge shelled cephalopods such as Cameroceras.
- 00:15:39This is a new level of superpredator. Some of the weird Cambrian groups,
- 00:15:44like the radiodon arthropods, had their whale counterparts, like the filter-feeding giant, Aegirocassis.
- 00:15:50Giant for the time at least. But the first fish also appear!
- 00:15:54They still don't have jaws, so they have to use weird mouths like Sacabambaspis.
- 00:16:00But they were also using armor against predators, this will be important later.
- 00:16:05But while our history has so far been all about water, the Ordovician saw the
- 00:16:11emergence of the first land plants. At that time, they were still
- 00:16:15limited to very humid environments, such as beaches, rivers and floodplains.
- 00:16:20These first bryophytes began the hard work: building the soil,
- 00:16:25the foundation of terrestrial ecosystems. The Ordovician ends with the first
- 00:16:30mass extinction on the planet, and the second most severe of all, eliminating more than 85%
- 00:16:35of living beings at the time. A glaciation took place,
- 00:16:38but much is discussed about terrestrial and extraterrestrial causes of this mass death event.
- 00:16:46SILURIAN In the Silurian, further
- 00:16:48diversification after the extinction increased the share of fish in the fauna,
- 00:16:53but carnivorous sea scorpions were still a headache for the jawless fish.
- 00:16:58Until at a certain point, they learned to bite back.
- 00:17:01The emergence of jawed fish revolutionized the oceans.
- 00:17:05They soon split between cartilaginous and bony fish, which coexisted
- 00:17:09with less derived types of fish. Some fish had the ingenious idea
- 00:17:13of having pumped-up fins. I have muscular fins!
- 00:17:17Bombed? I meant WOBS. We'll keep an eye on those over there.
- 00:17:22Dangerous elements. Meanwhile, on the continents,
- 00:17:26those bryophytes piled up so high that they supported giant fungi 8 meters
- 00:17:31high, like Prototaxites. The fungi's powerful enzymes
- 00:17:35process rock and dead organic matter, transforming soil from an
- 00:17:41infertile pile of dust into the living system it is today. They were at the time the tallest living structures
- 00:17:46on the continents, but they would soon be surpassed by plants, which had just unlocked a
- 00:17:52very important skill: the transport of water and nutrients through vascular tubes.
- 00:17:58The first vascular plants appear, which reproduced with unicellular spores, and were
- 00:18:03restricted to humid environments. Its advantage was that it could reach farther
- 00:18:08from bodies of water with its roots, and grow taller with its new water transport system!
- 00:18:13This is important, because every piece of land that gets the sun without any plants
- 00:18:18is like an empty buffet in the plant world. Some of the arthropods got tired of the
- 00:18:23unbridled bleeding that rolled in the oceans at that time and managed to make a living in the
- 00:18:28primitive continental ecosystems, not knowing that soon it would be just as crowded.
- 00:18:34DEVONIAN The Devonian arrives,
- 00:18:35known as the age of fish! Wow, the jaw thing really caught on!
- 00:18:41The first sharks and placoderms, such as Dunkleosteus, which could reach 7 meters,
- 00:18:45took over as the most feared predators in the ocean, and that position will never go back
- 00:18:51to invertebrates. Because they don't have hands.
- 00:18:55In a sense, modern ecosystems are established in the Devonian:
- 00:18:59In the ocean, with an age of fish that continues to this day, and on the continents,
- 00:19:05the development of the first forests. These trees are actually ferns,
- 00:19:10lycophytes and giant horsetails, which still reproduced by spores,
- 00:19:14and therefore, however much they could advance much further inland, it was nothing compared to
- 00:19:20modern plants, which manage to live even in deserts. Beneath the canopy of these first forests,
- 00:19:25terrestrial arthropods were having a feast. The first insects diversified,
- 00:19:31along with myriapods and chelicerates. A few lobe-finned fish decided
- 00:19:36the dry land was too cool to do without... these are
- 00:19:40tetrapods, which means four legs. I think this sounds familiar to you.
- 00:19:45It took 20 million years, but these early tetrapods gave rise to the first amphibians.
- 00:19:50Which are tetrapod fish adapted for a life between water and Earth.
- 00:19:55You might think that evolution was linear and that these fish were all
- 00:19:59desperate to continue to adapt to life on the continents, but that wasn't the case.
- 00:20:04Amphibians had everything in the water. That's where they laid their eggs
- 00:20:07and fed, and besides, the mainland was full of
- 00:20:11animals... hmm... uncharismatic, to say the least. Another mass extinction shakes the diversity of the
- 00:20:18Devonian, and opens the way for the Carboniferous. Oh! And trilobites are still around.
- 00:20:24CARBONIFEROUS As the soil continued
- 00:20:27to be built by plant communities, and the warmer, wetter climate cooperated,
- 00:20:33a global forest was installed during the Carboniferous. These plants used lignin,
- 00:20:37a very strong but malleable molecule, to build their huge, tall bodies.
- 00:20:42This molecule is great for the plant, but indigestible for bacteria and fungi.
- 00:20:47These forests had something profoundly wrong with their carbon cycle:
- 00:20:52they took carbon dioxide out of the atmosphere and put oxygen back in during life, but during
- 00:20:59death, the decomposers were unable to convert oxygen
- 00:21:03back into carbon dioxide, completing the cycle. When these trees died,
- 00:21:08instead of completely decomposing, they were buried one on top of the other.
- 00:21:12Gradually, oxygen accumulated in the atmosphere, and carbon in the soil.
- 00:21:17All this oxygen allowed the evolution of giant arthropods, such as meganeura,
- 00:21:22which also used another novelty: flight.
- 00:21:25Insects became the first flying animals.
- 00:21:28But the mainland was teeming with other huge arthropods, such as arthropleura.
- 00:21:33And it could have been the world of spiders, if not for a brave lineage of tetrapod fish
- 00:21:39that gave rise to land fish: amniotes. They learned to lay eggs with shells that
- 00:21:45protected them from drying out, and from there, bye bye water!
- 00:21:49By the end of the Carboniferous, amniote fish were already divided into two factions,
- 00:21:53the sauropsida and the synapsida. The difference is the amount of
- 00:21:57holes in the skull just this time, but they still all looked like lizards.
- 00:22:01At the end of the Carboniferous, global rainforests collapse
- 00:22:05in the first great continental extinction. They buried atmospheric carbon with
- 00:22:10their badly decomposed trunks piled up over eons, to the point of reducing
- 00:22:14the Earth's greenhouse capacity and generating a glaciation and consequent mass extinction.
- 00:22:19It was at this time that most of the fossil coal was formed, hence the name Carboniferous.
- 00:22:26PERMIAN Pangea
- 00:22:27was fully formed, and supercontinents tend to form huge deserts at their centers.
- 00:22:33This combined with a glaciation at the South Pole, promoted an almost global desertification.
- 00:22:38But little by little, the climate became more favorable for life on the continents.
- 00:22:43In the plant world, gymnosperms emerged, such as modern pines and araucaria,
- 00:22:48which, unlike the former pseudotrees, now used seeds, which are
- 00:22:52multicellular and resistant to periods of drought. Until then, plants used single-celled spores
- 00:22:59to reproduce, as ferns still do today. A new type of forest was emerging, better suited
- 00:23:05to animals that could tolerate dryness. The amniote fish saw their big
- 00:23:10break at that moment! This was the first time that they played
- 00:23:13a leading role in terrestrial ecosystems, and since then, it has never ceased to be so.
- 00:23:18During the Permian, they stop looking like lizards
- 00:23:21and start exploring shapes... too much. The animals of that time were something from another
- 00:23:27world, and unfortunately the time here limits me to just saying that they should be better known.
- 00:23:32These tetrapod fish communities that inhabited Pangea during the Permian were
- 00:23:37the first true continental megafauna. They explored various aspects of herbivory,
- 00:23:42carnivory, climbing trees, swimming in rivers... And surprisingly, it seemed that synapsid fish
- 00:23:48, or the ancestors of mammals, were becoming the dominant lineage.
- 00:23:52The Permian was, in a sense, a failed first age of mammals.
- 00:23:57But paradoxically, if it had never failed,
- 00:23:59true mammals would not exist. At the end of the Permian, 252 million years ago,
- 00:24:06the most brutal mass extinction of all time wiped out more than 90% of the planet's species.
- 00:24:12A huge lava flow in Siberia lasted thousands of years, its soot and
- 00:24:18volcanic smoke darkening the sky, suffocating plants and animals and poisoning the waters.
- 00:24:23This is called the great death, the mother of all mass extinctions.
- 00:24:28The closest animal life has ever come to simply failing.
- 00:24:33Thus, the Paleozoic era ends, and the few survivors would inherit the
- 00:24:38entire planet and found the Mesozoic era. This time, the challenges were too tough
- 00:24:44even for the trilobites, who are living their last days at the end of the Permian.
- 00:24:50TRIASSIC The Triassic begins with the
- 00:24:53Earth scorched and the biosphere depleted. Pangea still made
- 00:24:58climate conditions difficult for land animals, and ecosystems on continents took
- 00:25:0420 million years to restore end-Permian diversity.
- 00:25:07Now, the roles were the same, but the actors were different.
- 00:25:12The synapsid fish, which until then dominated everything, are limited to two basic survivors:
- 00:25:18the lystrosaurus dycynodont and the trhinaxodon cynodon, let's keep an eye on that one!
- 00:25:23Lystrosaurus is perhaps the most emblematic surviving species of the great death.
- 00:25:28They buried themselves, which may have been a key ability
- 00:25:32to traverse the Permo-Triassic passage. At the beginning of the Triassic, they had a rave,
- 00:25:38and never again did terrestrial ecosystems have such an absurd dominance of a single species.
- 00:25:43For a while, they even diversified, grew and gave rise to Placerias,
- 00:25:49weighing one ton, but also Lisowicia, the first giant of the age of dinosaurs, weighing 7 tons!
- 00:25:55Ironic that he is a much closer relative of mammals.
- 00:25:59But it was not to last, and from the middle of the Triassic onwards, a series of bizarre reptiles
- 00:26:04came to dominate the world, the dicynodonts went to the marsh, only cynodonts were left
- 00:26:09to represent the synapsids. The pangea was beginning to break up,
- 00:26:13and the weather was getting wetter and more pleasant. A group called archosaurs came to prevail.
- 00:26:19They gave rise to pterosaurs, crocodiles, phytosaurs, and a host
- 00:26:25of other extinct lineages, such as aetosaurs, which superficially resemble
- 00:26:30armed herbivorous crocodiles. To exemplify the diversity of
- 00:26:34archosauromorphs in the Triassic, I want you to meet Tanystropheus, an animal with a
- 00:26:40gigantic neck associated with semi-aquatic habits. Don't you have a stick? Be the stick!
- 00:26:47Effigia was a beaked, herbivorous, bipedal crocodile that could
- 00:26:51easily be mistaken for a dinosaur. But also Shringasaurus, the closest
- 00:26:57life has ever come to a dragon, only lacked wings. All these archosaur fish competed by occupying
- 00:27:03the different niches left by the great death. Dinosaurs weren't necessarily
- 00:27:08dominant, but they were beginning to diversify. They were bipedal and generalist,
- 00:27:13like herrerasaurus. Or sauropodomorphs,
- 00:27:16such as Plateosaurus, which were the largest dinosaurs of the Triassic, weighing 4 tons.
- 00:27:20The Triassic was also the end of the monopoly of fish in the oceans, when the first groups of
- 00:27:26aquatic reptiles, such as ichthyosaurs, appeared . This lineage of aquatic reptiles
- 00:27:30gave rise to the first truly giant animal: Cymbospondylus
- 00:27:34The Triassic comes to an end with yet another mass extinction, and gives way to the Jurassic.
- 00:27:40This is why Triassic animals are so strange to us, because they are
- 00:27:44caught between two mass extinctions, and they originated from the most severe one of all.
- 00:27:49Thus, most Triassic animals lived only in the Triassic.
- 00:27:54But some of the survivors of this extinction you definitely know!
- 00:27:59JURASSIC During the
- 00:28:00Jurassic, the age of the dinosaurs is in full swing!
- 00:28:03They were the winners of the extinction lottery, and in addition to sauropods and theropods, ornithischian dinosaurs
- 00:28:09begin to diversify. In these coniferous forests and
- 00:28:14low ferns, sauropods fed, a group of
- 00:28:18giant herbivorous dinosaurs that produced species known as diplodocus and brachiosaurus at that time.
- 00:28:24They were, at that time, the largest animals that continental ecosystems had ever produced!
- 00:28:29The apex of gigantism in history. Other very important players* were
- 00:28:35ornithischian herbivores such as stegosaurs and theropod carnivores such as Allosaurus.
- 00:28:40This new better life condition was mainly the fault of geological changes,
- 00:28:44and consequently climatic changes caused by the rupture and fragmentation of Pangea.
- 00:28:48With more coastal areas, moisture could reach more places, and life
- 00:28:53on continents became richer and more productive. A group of small feathered dinosaurs
- 00:28:59called Coelurosaurs gave rise to the bird lineage, the Paravian dinosaurs.
- 00:29:04But these paravian fish still didn't fly well, and yes, they used their feathers for a variety
- 00:29:11of purposes, such as thermoregulation, display, protection and to glide between one tree and another.
- 00:29:17The small cynodonts that survived the passage into the Jurassic were also beginning to
- 00:29:22diversify into the first true mammals. It is at this time, more than 150 million years ago,
- 00:29:28that mammals are divided into lineages that would continue to lay eggs, such as monotremes,
- 00:29:33and marsupial and placental mammals, each with its own delivery and breastfeeding strategy.
- 00:29:40Despite remaining small and unable to compete in dinosaur niches,
- 00:29:46mammals were plentiful! They were already gliding from
- 00:29:51tree to tree, like Volaticotherium, or swimming in shallow water, like castrocauda.
- 00:29:56But many of them still looked like Juramaia or Morganucodon.
- 00:30:01The Jurassic would end with a reasonably intense extinction,
- 00:30:05but dinosaur dominance prevailed, in an increasingly hotter and wetter world.
- 00:30:10CRETACEOUS The Cretaceous was
- 00:30:12the time of the most charismatic dinosaurs! Avian coelurosaurs diversified
- 00:30:17and began to compete with pterosaurs for the skies.
- 00:30:20But another lineage of coelurosaurs grew up to become a type of
- 00:30:24supercarnivore, like Tyrannosaurus rex! Other types of dinosaurs that appear
- 00:30:29at this time are ceratopsids, hadrosaurs and ankylosaurs.
- 00:30:33Sauropods break new size records, with the emergence of the titanosaur group,
- 00:30:39such as Patagotitan, much larger than their Jurassic ancestors!
- 00:30:44A group of pterosaurs also experiment with gigantism,
- 00:30:47the Azhdarchidae, such as Quetzalcoatlus, which gained fame as a flying giraffe.
- 00:30:52He was the largest animal to fly in the history of the planet,
- 00:30:55with wings measuring 13 meters from tip to tip. The Cretaceous is immense, lasting about 80 million
- 00:31:02years. There is more time between the beginning and end of the Cretaceous than there is between the end of the Cretaceous and today.
- 00:31:08Tyrannosaurus rex, for example, was one of the last non-avian dinosaurs to roam Earth.
- 00:31:13They were there when it all ended. But this species only lived in the last 2 million
- 00:31:19years of the Cretaceous, 66 million years ago. Stegosaurus lived 100
- 00:31:24million years before that. That is, the T rex is closer
- 00:31:28in time to us than the stegosaurus. A very important event of the Cretaceous
- 00:31:33was the emergence and diversification of angiosperms, flowering and fruiting plants.
- 00:31:37Today, this group is 300 times more diverse than the gymnosperms that
- 00:31:43dominated until the end of the Jurassic. And who knew that a simple flower
- 00:31:47like archaefructus would change everything! They associated with insects, and they
- 00:31:51became part of the reproductive cycle of plants, in exchange for easy energy.
- 00:31:55The Cretaceous experienced an explosion of insect diversity, especially
- 00:32:00those considered to be insect superorders. At that moment in time, the first societies began to appear
- 00:32:06, such as those that ants began to organize.
- 00:32:10They still didn't have such clear divisions of labor, and they lived in colonies of around
- 00:32:15100 ants, but it was something unheard of. By the end of the Cretaceous, the young
- 00:32:19Atlantic Ocean was growing, and Pangea was just a distant memory.
- 00:32:23With more fragmented continents and a high degree of active volcanism, the
- 00:32:29Cretaceous climate was much more homogeneous and the temperature was 10 degrees warmer on average than today.
- 00:32:35Forests had a global distribution, and palm fossils are found from
- 00:32:40Alaska to Antarctica, proving that these places were much more productive than they are today.
- 00:32:45During a spring 66 million years ago, a space object
- 00:32:5012 km in diameter hit Mexico's Yucatán Peninsula, bringing the Mesozoic to an end.
- 00:32:56PALEOGENOUS Fortunately, some lineages of reptiles,
- 00:33:00amphibians, mammals and avian dinosaurs that weighed less than 10kg survived to tell
- 00:33:06the story and usher in a whole new world. This is the Cenozoic, the era we live in until today.
- 00:33:12It took nearly 10 million years for ecosystems to recover, and for
- 00:33:18a while, the world was relatively empty. When forest biomes were restructured,
- 00:33:24flowering plants were in the absolute majority, and a new type of forest,
- 00:33:28much denser and wetter, was established. In the beginning, the climate was getting
- 00:33:33wetter and hotter every day , and forests dominated the entire world: from the equator to the poles.
- 00:33:39This new, warmer climate is ideal for reptiles, which produced some of the craziest predators
- 00:33:44before modern carnivores evolved. Once the dinosaurs became extinct,
- 00:33:50South America became a hot and humid tropical paradise for giant reptiles.
- 00:33:54It was here and at that time that Titanoboa lived, a gigantic constrictor boid snake,
- 00:34:00capable of eating animals the size of a horse. Carbonemys was a giant tortoise the size
- 00:34:05of a car, which may have coexisted with Titanoboa, with a life style
- 00:34:09similar to today's snapping turtles. Huge alligator and crocodile genera
- 00:34:14such as Purusaurus have long thrived in South America.
- 00:34:18In Antarctica, which at the time was a group of islands at the south pole, the absence of predators
- 00:34:23allowed the evolution of communities of giant penguins, as tall as a person,
- 00:34:28such as Anthropornis and Palaeeudyptes! This penguin club encompassed
- 00:34:33the entire South Pole, which is why, to this day, penguins only exist in the Southern Hemisphere.
- 00:34:37This was the closest the dinosaurs came to reconquering the planet.
- 00:34:41But throughout the rest of the world, mammals, the last representatives of the synapsid lineage,
- 00:34:47diversified and occupied the places previously occupied by dinosaurs, avenging their
- 00:34:53Permian ancestors, 200 million years later. During this period, the Plesiadapiformes*,
- 00:34:59animals that looked like a cross between a lemur and a squirrel, appeared,
- 00:35:03and we're going to hear a lot about the descendants of this weird tree-dwelling fish.
- 00:35:08NEOGENE 23 million years ago,
- 00:35:11the neogene begins, marked by climate and environmental changes that would make the world
- 00:35:15more recognizable to the inhabitants of the present. The Indian subcontinent completely slammed
- 00:35:21into Asia, producing the largest mountain range on planet Earth.
- 00:35:24This has increased the weathering of rocks, which are carried as sediment from rivers to the ocean,
- 00:35:30where they help fertilize photosynthesis and build shell skeletons.
- 00:35:34This, in turn, causes more carbon to be taken out of the
- 00:35:38atmosphere and buried under the ocean floor. Added to the isolation of Antarctica at the South Pole,
- 00:35:43which created a powerful ocean current, the world became much colder and drier.
- 00:35:48Antarctica is slowly being frozen, losing its forests and becoming more
- 00:35:53inhospitable every day, until it reached the extreme climate of today, where only a few species of penguins
- 00:35:58specialized for the cold survive. The global forests have given way to a
- 00:36:03variety of biomes, most notably grassy open fields.
- 00:36:07It was in adaptation to this type of environment that the fauna of modern mammals evolved.
- 00:36:12Hoofed animals, hoofed mammals, become the main type of herbivore,
- 00:36:17and carnivores such as dogs, cats, and bears eliminate competition from other lineages
- 00:36:22of primitive carnivores, such as creodonts. By the end of the Neogene, virtually all living animal groups
- 00:36:28are familiar and recognizable. Also in the Neogene, we have news of the
- 00:36:33first true apes. Until then, our lineage had the face of
- 00:36:37a lemur, with a snout of a dog, but then they split into the apes of the old and new worlds.
- 00:36:42Like the rodents, they managed to reach South America
- 00:36:46and give rise to all our native apes, probably via a raft of vegetation.
- 00:36:51Among the monkeys of the old world, hominins appear,
- 00:36:54and within them, genera such as Ardipithecus, one of the first truly bipedal apes.
- 00:37:00These hominin fish gave rise to the genus Homo, specialized in bipedal posture
- 00:37:05and with impressive manual and intellectual abilities, such as Homo habilis and Homo erectus.
- 00:37:11QUATERNARY The Quaternary period
- 00:37:12begins 2.6 million years ago, and encompasses the Pleistocene and Holocene epochs, with the
- 00:37:19latter beginning 12,000 years ago and lasting until today. You, and all of us, live in the Holocene Epoch,
- 00:37:26in the Quaternary Period of the Cenozoic Era in the Phanerozoic Eon.
- 00:37:31This period is marked by a deepening of the glaciation that had already begun to freeze
- 00:37:36the South Pole, now, extensive ice sheets also occur at the North Pole of the Earth.
- 00:37:41Contributing to glaciation, the tropical circulation of the Atlantic Ocean is interrupted
- 00:37:47when South America touches the north through the uplift of the Isthmus of Panama.
- 00:37:52In the Quaternary, the North and South American faunas merged permanently,
- 00:37:57in the so-called Great American Interchange. The broad savannah conditions and the new
- 00:38:01climate stimulated and selected for gigantism among mammals, among them the
- 00:38:07most charismatic animals of the ice age megafauna, such as giant sloths and woolly mammoths.
- 00:38:12About 300 millennia ago, our species appears in East Africa, and from there, it spreads,
- 00:38:18meeting all the other 5 humanities that cohabited the planet.
- 00:38:2250,000 years ago, there is a cognitive and cultural explosion that takes
- 00:38:27tool-making to a new level and sophisticates artistic works such as
- 00:38:32paintings, handprints and sculptures. Soon, only Homo sapiens remained alive.
- 00:38:37Between 20,000 and 10,000 years ago, much of the megafauna collapsed,
- 00:38:42depriving humanity of much of its game and forcing humans to invent inventive solutions.
- 00:38:4810 thousand years ago, at the beginning of the Holocene, agriculture appears,
- 00:38:52and soon it spreads all over the world. This bipedal fish had just mastered
- 00:38:57domestication over plants and other fish that served to eat and work.
- 00:39:01With agriculture, populations could grow exponentially, and that's how
- 00:39:06the first cities emerged on the banks of large rivers. The fad of civilization caught on,
- 00:39:11and the world's population slowly increased. 400 years ago, modern science,
- 00:39:17astronomy, physics and the kind of political philosophy that guide us to this day were born.
- 00:39:21With this new way of thinking about nature, technology accelerated like never before!
- 00:39:26Soon, electricity was introduced, permanently revolutionizing the world
- 00:39:31and allowing for a whole new range of technologies and ways of life.
- 00:39:35Factories began to dominate and many products were produced quickly,
- 00:39:40it was the beginning of industrial capitalism. It is based on the burning of
- 00:39:44fossil fuels as the main source of thermal and electrical energy generation.
- 00:39:47The coal accumulated in the Carboniferous, which was lacking during the Karoo glaciation,
- 00:39:52is now burned to satisfy the
- 00:39:54material needs of a new world. Agriculture has taken over
- 00:39:58a good part of natural ecosystems and our garbage, chemical pollutants and plastics
- 00:40:03have triggered a global mass extinction. Since then, human life has been defined
- 00:40:09by the degradation of environmental conditions and the political struggle for power, property and status.
- 00:40:15Today, our future is defined by two major disruptive challenges:
- 00:40:19The first is the continuity of capitalism in a demographically aged economy
- 00:40:24in the contemporary age of artificial intelligence, or the knowledge economy
- 00:40:27And the second is the climate crisis itself and the environmental catastrophe that it can produce
- 00:40:33climate refugees in the billions this century, mostly in developed countries.
- 00:40:38And even with all that, lobe-finned coelacanth fish
- 00:40:42managed to survive to this day. They've been known for a long time
- 00:40:47in fossils, and they've helped apes understand that they're a
- 00:40:50super weird kind of fish. We thought they went
- 00:40:54extinct along with non-avian dinosaurs, and even in the Cretaceous it
- 00:40:58was a living fossil 360 million years old. That's why, in 1938, they were so shocked
- 00:41:05when a fisherman simply caught one alive. In the words of the scientist who first recognized
- 00:41:10this fish in the flesh, it was more absurd than seeing a dinosaur walking down the street.
- 00:41:15Moral of the story: you are a fish. Once inside a group, it is impossible to leave.
- 00:41:21If we want to form a biological group called “PISCES”, we have to include a
- 00:41:25common ancestor and ALL of its descendants. When we exclude tetrapod fish from this
- 00:41:31category, it becomes artificial and has no validity in an evolutionary sense.
- 00:41:35That's why I made a point of remembering all the time that all
- 00:41:39terrestrial vertebrate creatures are still fish. There is a humbling lesson in that. But
- 00:41:44you have to look closely at a fish to understand. You will recognize yourself.
- 00:41:48I hope that looking to the past is a way of being able to look to the future.
- 00:41:52I like to believe that humanity is just beginning, and that the technological means that exist
- 00:41:57today will lead our species to a prosperous future compatible with the health of nature.
- 00:42:02We don't need to suffer the same fate as the dinosaurs,
- 00:42:05we now have the means to detect and deflect the orbit of a dangerous space object towards Earth.
- 00:42:11We are now unlocking the secrets of DNA editing, which could give rise to a whole new medicine.
- 00:42:17Artificial intelligence is changing the workforce paradigm and can bring
- 00:42:21more free time and productivity to humanity than ever before.
- 00:42:24But it's up to us to produce the news of this new world, which will make all of this start to
- 00:42:30benefit us, and not destroy our jobs. Human intelligence can be a heritage
- 00:42:34not only for our species, but for the entire terrestrial biosphere.
- History
- Geological Time
- Life Evolution
- Big Bang
- Dinosaurs
- Mammals
- Homo Sapiens
- Climate Crisis
- Artificial Intelligence
- Future of Humanity