You Are Here

the Earth the Blue Planet an ancient Oasis Of Life suspended in the darkness of space throughout its long chaotic history it has experienced countless drastic changes which have profoundly shaped its destiny and now after almost 5 billion years you are here as rich and illustrious as this world is today it was once nothing more than a column of dust dancing inside a scorched Cyclone of Stellar gas which ignited the Sun and just how we managed to transition from said dust to this living world of unfathomable complexity and depth makes up the topic of our video today so join us as we wind the cosmic clock backwards billions of years from you and I today all the way back to the birth of the solar system when Earth was nothing more than a burning Barren Wasteland [Music] Our Story begins four and a half billion years ago when the universe was about 9.3 billion years old we know this because the very oldest rock formations we have found are roughly that old rocks have a fantastic way of telling us their age through the process of radiometric dating by making use of the consistent rate of radioactive decay in rock formations we can extrapolate with great Precision when they were last hot and Earth's oldest rock was blisteringly hot around four and a half billion years ago back then the infant sun was only just beginning to shine erupting beams of energy which dispelled the incubating envelope of gas surrounding it during its formation this gas then recollected in orbit around the star and over about 10 million years condensed to form the Solar System's planets on the inside of the young system it would have been far too hot to facilitate the icy buildup of giant planets like Jupiter Saturn Uranus and Neptune instead all that could condense this close to the young son were Rock molecules culminating in the accretion of about 30 sub-earth-sized molten planetary embryos once the solar system had taken shape these Rocky bodies then began colliding under the influence of gravity obliterating one another and Blasting most of them to smithereens after a few tens of millions of years the debris from this age had concentrated further into a handful of terrestrial protoplanets vying for A Place in the Sun among them the young smoldering Earth its mass had become so great that heavy elements and metals near the surface started sinking towards the center of the planet establishing Earth's internal layered structure and slowly switching on its protective magnetic field as Heats continue to swell and bubble beneath the tortured surface volcanic activity ravaged and reshaped the face of the planet blanketing it with sediment driving away the early light elements left over from the formation of the sun it's replaced them with a thick choking atmospheric layer of toxic greenhouse gases particularly nitrogen carbon dioxide and methane and yet even despite the hellish conditions of the hadian era Earth still managed to support a familiar sight on its molten surface liquid water but this ancient body of water would have been roasting acidic and standing much higher than sea levels today and it soon boiled away to fill the atmosphere with water vapor it was only after global temperatures had fallen several hundreds of millions of years later that this Vapor was able to condense and just under 4 billion years ago at the end of the hadian era clouds gathered in its ancient sky before raining down every day for over a hundred thousand years this downpour refilled the parched basins left by the progenitor ocean and completed its transition from scorched molten rock to a blue planet covered in liquid water signaling the start of the second of Earth's four great eons the archaean period it was in this age that Earth would see its defining characteristic arise Like a Phoenix From the Ashes life woke for the first time on the planet as asteroids continue to bombard the surface of the terrestrial worlds Earth's oceans provided a new unlikely source of shelter on their seabeds furthermore as convection currents swirled in the mantle below hydrothermal activity punched through the ocean floor erupting mineral-rich deposits and bursts of heat exposed to the cold of the ocean these eruptions almost instantly condensed into tower-like structures of precipitate resembling miniature seabed volcanoes known as hydrothermal vents entities within the sheltered pockets and grooves of these towers where we believe life on Earth First emerged though it might seem like a hostile environment for something as delicate as the first life forms these vents actually made the perfect Laboratories for abiogenesis providing energy through their excess heat a source of chemical compounds in the mineral Rich ejector and finally a solvent the seawater for mixing things and facilitating chemical reactions and with the prerequisites for an Awakening of life now falling into place complex chemical reactions began to ensue under such conditions freshly synthesized organic compounds would have started clustering into Aggregates molecules known as protobions which somehow started to coordinate their behaviors we still don't really know how let alone why but it would seem that an accumulation of complexity over time would have developed these molecules further until some 3.8 billion years ago when an irreversible threshold was crossed whether there was one Awakening or several remains a topic of debate among scientists to this day but in any case the first recognizable organisms emerged in these events and Earth was now a living world the first life forms would have constituted extremely primitive bacterial cells known as prokaryotes single-celled organisms which lacked nuclei and reproduced via the simplest forms of binary fission and fragmentation in any case the prokaryotes population started to expand until it was able to move out of the hydrothermal vents and two distinct domains of life were established to which everything that has ever existed traces its lineage bacteria and archaea broadly similar in size and structure these two varieties of cells went on to colonize and rule the oceans for more than one and a half billion years accumulating on the surface of rocks in sheet-like colonies of microbial mats which over time were petrified and remained preserved in the fossil record today a few contrasting species and sub-varieties emerged coexisting and interacting to give rise to the first evolutionary adaptations and within 400 million years a new species of algae-like microbe known as cyanobacteria stopped sourcing its energy from the heat spewing up from Earth's vents and instead floated upwards into shallower Waters to bask in the light of the Sun this game-changing new ability known as photosynthesis allowed the cyanobacteria to explode in number in the shallow depths blanketing Earth's oceans in a slimy green coating the first algal bloom was in full swing as the archaean period due to a close some two and a half billion years ago the sun setting on an extraordinary age of innovation and evolution and to the next of Earth's great chapters the proterozoic period the longest of the four lasting two billion years would see yet more strides towards the emergence of complex life driven by a number of seismic changes to earth's atmosphere as mentioned Earth's early atmosphere consisted largely of greenhouse gases with its share of oxygen so essential for Life Today accounting for less than naught Points North one percent with most of the biologically produced oxygen pumped out by the cyanobacteria absorbed by the Earth's oceans but heading into the proterozoic period these oceans began to freeze and the atmosphere called along with them 2.2 billion years ago the first of two great ice ages engulfed the planet as temperatures plummeted even greater expenses of the ocean froze and the exchange of gases between the sea and sky was constrained leading to a reduction in atmospheric carbon dioxide causing the greenhouse effect to wane with less CO2 the planet's temperatures fell even further meaning more ice built up on the ocean's surface which reflected a greater amount of sunlight driving an even colder climate still before long a runaway snowball Earth event was in motion as its glaciers migrated all the way down to the Equator encasing the entire planet in a shell of solid ice and with the oceans completely locked away oxygen could now begin accumulating in the atmosphere raising its concentration to around one percent while it might sound like a negligible increase the gas was now over a hundred times more prevalent than before the aptly named great oxidation event it had risen so unsustainably in the air and ocean that it wreaked havoc on most of the anaerobically respiring biosphere the archaea family were the most affected with around 80 percent of its cells dying off as a result of this oxygen catastrophe those that remained were forced to either alter their structures to tolerate oxygen or risk Vanishing altogether and thus the first instance of evolution via survival of the fittest occurred those archaeal cells with random mutations that happen to accommodate oxygen enabled them to survive and reproduce while the more conventional poorly suited cells perished and so the archaea family was pruned by natural selection incentivizing life to take its next great step as a new subdomain of archaeal cell emerged known as the eukaryote substantially larger and more complex than its bacterial and archaeal counterparts eukaryotes were also the first cells to house a nucleus capable of storing and sharing genetic information though they initially reproduced asexually via mitosis it was these cells that evolved the first sexual reproduction and ever since they have come to Encompass large swathes of the modern day biosphere as the principal cell type of humans animals plants and fungi and for a further one and a half billion years these cells quietly establish themselves in Earth's oceans as they were gripped by yet another snowball event this second great Ice Age enabled the level of free oxygen in the atmosphere to jump once more to a considerable share of more than 10 percent but before long a surge in volcanic activity was pushing back melting this icy shell and replenishing CO2 lost from the atmosphere as the planets defrosted once more Earth's oceans were now ready to unlock perhaps the single most important adaptation of Modern Life multicellularity multicellular aggregations would amplify the potential of Life on this planet immeasurably and it's the end of the second Ice Age around 600 million years ago it was poised to take off in a big way in fact multicellular creatures are believed to have evolved independently on this planet at least 25 times over the course of its history including multiple times for plants for some reason Earth's oceans suddenly became much more accommodating to self-determining aggregations of microbes this was likely due to a number of factors coming into alignment one being the Abundant free oxygen now lingering in Earth's atmosphere another would have likely been the chemical enrichment of Earth's oceans as eroding continental crust washed new minerals into the sea both factors are thought to have played a crucial role in developing the next building block of Life amino acids organic molecules containing oxygen that make up the basis of proteins and in turn the Twisted fibers Binding Together complex creatures by the end of the proterozoic period 540 million years ago an abundance of the compound collagen was racking up in Shallow seas and was starting to influence cellular life laboratory experiments have proven Beyond reasonable doubt that cells cluster and reproduce much more vigorously in the presence of collagen it forms a sort of net over groups of microbes which allowed them to shape the first cell tissues initially this facilitated the appearance of poorly adapted slug-like aggregations of cells known as aggrex but with more cells came more room for error when reproducing the organism allowing for a wider range of more diverse adaptations the best of which would have been quickly teased out by natural selection and so moving into the final of Earth's four great eons the ongoing phanerozoic era Evolution was able to move at a pace that has never been matched since and the stage was set for a biological Big Bang of complex life at about 530 million years ago we do indeed find evidence of such an Awakening imprinted all over the fossil record as we enter the Cambrian Period also known as the Cambrian explosion most of the animal body plans or phyla that we see on Earth today emerged within this comparatively brief 15 million year window the biological destiny of life was sealed for hundreds of millions of years to come as it spread the first familiar characteristics like hard exoskeletons tails and eyes to accompany the ability to move brains became larger with skulls forming around them followed soon after by jaws and backbones Plankton populations began skyrocketing establishing the bases of the first food chains around the same time we begin to see bites appearing in the fossil record within a food chain comes winners and losers predators and prey suddenly traits such as speed stealth and subtlety became desirable and before long a fully fledged biological arms race was underway this arms race is best illustrated by the plight of the trilobite family one of the earliest complex life forms to conquer the ocean floor these beetle-like creatures had a hard segmented shell and though they started out blind in immobile necessity soon spawned their ability to see move and eventually swim freely they spread out across most of the planet evolving more than 20 000 distinct species over 50 million years and over the course of this progression their adaptations grew more and more defensive they sprouted spines and grew horns and their exoskeletons turned to armor and all of this was likely in response to the emerging challenges of their new environment including the first well-adapted Predator to roam the high seas animalocaris this creature was among the first to have claws and A peculiar grounded mouth on the underside of its body both of which would have been useful in cracking open the shells of its prey thus the earliest populations of slow swimless trilobites were hunted to Extinction while their slippery spiny descendants continued to flourish another creature that was able to evade the tyranny of animalicaris was a small eel-like creature known as pikaya while only about five centimeters in length and lacking any defensive adaptations it did have one particular enhancement which would eventually become Central to the Animal Kingdom a long hard backbone running through the center of its body this allows the picaya to glide through the ocean currents to escape its predators allowing it to successfully evade capture and eventually reproduce thus we see the vertebrates body plan beginning to feature more prominently in the fossil record from here on out eventually enabling the evolution of another of the ocean's long-term Mainstays fish began appearing in the fossil record about 50 million years after the Cambrian explosion but the first generation were poorly suited to their environment one of their earliest known species arendaspis possessed a relatively streamlined vertebrate body but lacked fins and thus would have been an incompetent swimmer it also lacked a movable jaw and relied on sucking the seabed to extract microbes for sustenance the species soon became a food source for larger later better adapted fish which could swim adeptly and that did have Jaws which allowed them to bite their prey seeking Sanctuary from the increasingly perilous depths of the ocean floor these preyed upon fishes were driven from their original habitats towards fresh water environments such as lakes rivers and estuaries unfortunately for them however fresh water was toxic to most marine life the saline content of seawater played an important role in regulating the mineral content of cells without which they would start to rupture and die off therefore any fish that dared Venture into a freshwater habitat risks to slow painful and protracted death that was until one species perhaps the terraspis managed to make the first permanent sleep to Fresh Water by evolving a kidney within their body capable of pumping strenuous substances out of the bloodstream but this new environment brought other challenges along with it fast currents Jagged rocks and steep drops this necessitated the need for new freshwater adaptations such as lighter and more muscular fish with survivable skeletons contained inside the body and fins which would not tear or rupture so easily and it would be these adaptations particularly the latter that would start these freshwater creatures down the path to their greatest Conquest yet walking on the land by this time the floral Kingdom of plants was already achieving Mastery of land environments Shrubbery was widespread across the early super continents covering them in swampy wetlands and perhaps as early as 420 million years ago at the start of the devonian period the arthropods the descendants of trilobites and ancestors of modern day insects beetles spiders shellfish and millipedes began crawling out of these Wetland habitats and onto dry land ironically their hard lightweight exoskeletons and excess of legs made them well suited to this new environment prompting natural selection to quickly Elevate land conquering adaptations larger creatures however would have no such luck and it would be tens of millions of years more before the first amphibians would take steps on the land their Journey began in the swamps filled with pools of murky stagnant water thus ancestral species of fish found benefit in being able to poke their heads out of the water to breathe air when necessary and it was this ability that started to extract the first reptilian traits from these early fish longer heads and more maneuverable necks and eventually stronger fins that started to look more like limbs one of the earliest amphibious creatures acantha Steger was the birthplace of a number of these features with four sprawling legs where its fins were once located each with no less than eight spiny fingers though this would have greatly impaired its ability to swim acantha Steiger found success in using its limbs to meander across the riverbed into shallow protected areas covered by fallen tree branches which it could also use to hoist itself out of the water for the occasional breath of fresh air but it was not this creature that would be the first to crawl out of the ocean as the configuration of its limbs would not have allowed it to support its body weight without the buoyancy of water instead another of its limbed relatives ichthyostega is thought to have been among the first creatures to attempt the transition when it took no less than 260 steps on land in a swamp at the foot of the prehistoric Caledonian Mountain belt supporting its body weight all the while what enticed the creature to dry land remains a mystery but in any case and like the insect population once these creatures discovered the relatively untapped nutrient-to-rich ecosystem unfolding on the land there was no going back and natural selection quickly transcribed terrestrial adaptations such as lungs and land breathing into their genetic codes before long these creatures were unrecognizable as fish and looked more like lizards and indeed the rise of reptiles would come to characterize much of the next 300 million years with life now walking the land the devonian period often dubbed to the age of fish came to an end and so began the Carboniferous period the age of the supercontinent around 360 million years ago the three progenitor continents that existed on Earth gondwana your America and Siberia started slotting together to birth the principal supercontinent Pangea a new sprawling unified landmass now existed to be explored and life had not seen such an opportunity for growth since the Cambrian Period at first Pangea was Proud by a family of so-called mammal-like reptiles including a menacing Komodo dragon-sized lizard that came to be the dominant land predator for tens of millions of years but over the course of the Carboniferous period distinctions within this family started to appear as reptiles and mammals differentiated from one another as life continued experimenting with different biological blueprints it wasn't long before a new class of animal emerged the amniotes clade constituting an extensive variety of four limbed creatures identified by the presence of certain life-supporting adaptations within this order terrestrial life would diverge into two distinct types seropsids the ancestors of reptiles and birds as synapsids the ancestors of mammals like us the former was propelled to the summit of the terrestrial biosphere by a number of new groundbreaking adaptations most notably the ability to lay eggs as a means of reproduction this allowed the seropsida and their offspring much more freedom to roam their territory during their mating periods synapsids meanwhile were experiencing their own breadth of evolution as we start to see the emergence of bizarre transitional creatures on the fossil record known as the rhapsoda with a variety of different builds head shapes and jaw structures this peculiar family evolved to the first mammalian departures from their reptilian counterparts most notably a set of Limbs which extended underneath the body as opposed to sprawling outside the side like lizards one member of this family in particular the synodont is often attributed as the last common ancestor of the family mammilia forms constituting all present-day mammals and their extinct relatives but the synodont was generally quite small and meek and often preyed upon by larger more vicious reptilian creatures but around 300 million years ago at the end of the Carboniferous period Earth's biosphere began to collapse catalyzed by a gathering storm of devastating factors climate change habitat loss and the changing geology of Pangea meant that the Permian period which followed was marred by ecological disasters and extinctions starting with the fall of the rainforest ecosystem Earth's relatively Cosmopolitan distribution of jungles began to fracture fragment and recede while something even more catastrophic was brewing deep below the surface Parts way through the Permian period Earth experienced one of its most significant volcanic events ever forming the land mass today known as the Siberian traps this eruption lasted more than two million years and loaded Earth's delicate atmospheric balance with strenuous amounts of carbon dioxide global temperatures rocketed to unsustainable levels with both marine and terrestrial ecosystems affected Earth's remaining jungles were decimated with its trees almost Vanishing from the fossil record entirely along with many different species of synapsida and seropsida in total the Permian period saw no less than three distinct episodes of mass extinction over 50 million years culminating with the single most deadly die-off on record the late Permian Extinction event during this fatal chapter alone 57 of all biological families were lost including 70 percent of terrestrial life and 81 of marine life by the time the Permian period was over the biosphere had been reduced by a skin-crawling 95 bringing it to the very brink of eradication but among the many casualties there were survivors in fact it only took around 10 million years following the end of this great die-off for trees to bounce back and recover across much of Pangea and soon after the mammalian descendants of synodonts began returning to the surface from the shelter of their Burrows below but the rule of reptiles on land was far from over because another Survivor from this age were lizard-like reptiles with avian lineage which would go on to spread and recolonize the land during the Triassic period eventually evolving into the family we today know as the dinosaurs the earliest recognizable dinosaurs started appearing in the fossil record around 245 million years ago but they were a far cry from the gigantic beasts we've come to associate them with closer in size to a chicken than a T-Rex it took around 30 or 40 million years and a number of favors from Mother Nature for dinosaurs to establish themselves as the dominant terrestrial Force around this time the supercontinent Pangea began to fracture initially breaking into two large sub supercontinents which would slowly break apart into the seven contemporary continents we know today the ever-changing geology and temperature of the earth drove yet another mass extinction event which whittled terrestrial life down to only flying reptiles such as the pterosaurs the ancestors of crocodiles and a selection of dinosaurs marking the end of the Triassic period and the start of the Jurassic period and over the next 150 million years leading into the Cretaceous Period dinosaurs would spread to all parts of Earth spanning millions of different species with a myriad of different body plans among them some of the fiercest and most iconic Predators ever to walk the earth the Tyrannosaurus Rex and Velociraptor are often touted as instances of such apex predators primarily due to their significance in the Jurassic Park film series but in truth these movies exaggerated the abilities of the two types of creatures somewhat the Velociraptor in particular would only have been the size of a turkey and not the two meter door opening sobs we see in the film their design was actually based on a much older predator deinonicus a Sleek agile Runner that could grow up to 3.5 meters in length its Discovery derailed the mid-20th century perception that dinosaurs were almost exclusively gigantic slow-moving creatures like the Argentinosaurus which may have been able to grow up to 35 meters long based on skeletal reconstructions at such sizes it would have been hard to imagine what could possibly bring down this Kingdom of giants but something certainly did as they all but to vanish from the fossil record around 66 million years ago but it wasn't natural climate change or volcanism that drove the dinosaurs to Extinction in fact the apocalypse this time arrived from outer space as an enormous 10 mile wide asteroid plunged into the land that is now Mexico traveling at a speed of some 45 000 miles per hour on impact it struck with the force of 100 million Hiroshima atomic bombs releasing a catastrophic tsunami of fire and water which decimated the land acidified the oceans and extinguished the light of the Sun in a nuclear winter event driven by the collapse of photosynthesis and marine ecosystems about three-quarters of all life on Earth was once again wiped out including the near total obliteration of the dinosaurs but once again there were survivors to the stint of the Apocalypse particularly the rodents-like ancestors of modern mammals which had already spent much of the last 150 million years hiding to avoid their reptilian overlords and for the first time these creatures could now Venture up onto the forest floors as a new age of mammals started to Dawn mammals Rose to the top of the food chain for the very first time and was soon hunting other mammals for food the safest creatures were now those who ventured away from the forest floor perhaps into the thick Shady canopies of trees and thus at this point we see the family of primates starting to emerge with some familiar adaptations like curving thumbs on five fingered hands suitable for holding onto and swinging through tree branches as this family Diversified a plethora of new lineages emerged including the family of monkeys around 50 million years ago today they have a distinct place in the biosphere spanning a broad range of species set apart by the size of their brains and impressive cognitive abilities and over many millions of years their increasing size bore the family of Apes where the earliest recognizable ancestors of humanity would emerge fast forward to around two and a half million years ago and we see the first human-like beings of the genus homo among the earliest were the Homo habilis the first type of primates to begin shaping stones into tools like hooks it's culminated with the discovery and Mastery of fire about one and a half million years ago completing our transition from Mostly scavenger beings to efficient apex predators soon after a new species of so-called upstanding ape the homo erectus emerged with a flatter face Anita knows a more upright posture and an even larger brain they were clever enough to Fashion the first serious tools which allowed them to hunt and kill medium to large sized animals like bovines and elephants one species of their descendants includes the homo hedelbergensis which emerged around 770 000 years ago and is thought to be the most recent common ancestor between humans and Neanderthals fast forward again to around three hundred thousand years ago and the lineage of homo sapiens starts to appear with the most complex brains yet sophisticated enough to drive sentience as well as Innovative new ways to master their environments 165 000 years ago Homo sapiens were urbanizing the areas near water making use of complex tools to catch and cook shellfish and the practice of fishing would become invaluable to the prosperity of human colonies until about 12 000 years ago when the innovation of farming plants and animals took its place this enabled humans to spread out to new areas and explore their planets like never before championed by the Perfection of rafts boats and Maritime navigation humans spread to all seven continents and from there the preservation of human history makes things a bit easier to trace the rise of contemporary cultural practices and modern religions ancient Egypt Greece and Rome the Ottoman Empire the Middle Ages and the scourge of the Black Death the American separation from Britain World Wars one and two over the last three thousand years we've written a comparatively brief yet extensively detailed chapter in the history of this planet and not all of it is to be proud of but for better or worse it has all been leading to this moment and now you are here every single one of us represents an unimaginably tiny yet every bit as important piece of the puzzle constituting the greatest mystery in the universe The Mystery of Life and why it exists but no matter what else happens life has had to Wade tirelessly through all of its impossibilities its twists and turns its Awakenings and its extinctions to get to you so no matter what tomorrow brings always remember that you are here for a reason as we have seen today even the tiniest inanimate ships have the power to drastically change the world with time as sentient beings we have no excuse so go out there and spread Joy under an ancient sky and make tomorrow the day that really counts and with that I bid you good night C signing out

Channel: SEA

Views: 563,469

Keywords: Sea 1997, Sea, Space, OOTW, astronomy, science, LIFE, history of life, universe, space, biology, first life on earth, abiogenesis, biogenesis, microbes, bacteria, archaea, archean period, hadean era, snowball earth, eukaryote, multicellular, organism, trilobite, anomalocaris, pikaia, fish, amphibians, tetrapods, Acanthostega, pangaea, supercontinent, lizard, mammal, reptile, jurassic, triassic, extinction, homo sapien, humans, great oxidation, Cambrian explosion, earth formation, evolution, natural selection, dinosaur

Id: mQpoZrQ87uM

Length: 43min 49sec (2629 seconds)

Published: Sun Aug 06 2023