The First Life on Earth

is a very very special world is the only place in the universe that we know of where life has emerged and it hasn't just emerged on this planet it thrives in every single corner and last pocket from plants to animals to us the most complex humans but as we looked for life on other planets and other moons we've been looking for the very small things microbes bacteria traces of biological processes which makes the question if the other worlds in the solar system and perhaps light-years beyond are so barren and desolate and contain such little new possibilities of life then how did earth become earth is an exhibition of complex sophisticated multicellular life right now we know of over 1.2 million species they inhabit this planet and scientists believe that that is less than 1% of the total number of species that have ever emerged here different studies disagree on how many species of life there may be that remain undiscovered some say there may be as many as 14 million species out there while others suggests there may be billions from the tallest trees to the deepest oceans Earth's biosphere is unendingly diverse of rich but where did it all come from not the first animals not even the first microscopic creatures but what about the very first cells the first living things ever to emerge well to find the answer to that you have to go back billions of years back to when the earth was far younger and profoundly different it had just emerged out of the chaos of space but it was far from the beautiful blue planet we enjoy today [Music] creation begins with hydrogen the most abundant element in the universe since the beginning of time clouds of hydrogen and helium gas have existed right across space is within these clouds that the processes of creation occur the unassembled building blocks of stars planets black holes most importantly of all life around four-and-a-half billion years ago a cloud of this kind lay dormant in our region of space known as the solar nebula which was struck blasted by the shockwave of a huge nearby supernova explosion this wave showered the solar nebula with heavier elements fused by the foregone star which was now merely a ghost this unimaginable force woke the minimum rich cloud and it began to rotate rapidly in a chaotic vortex millions of kilometers wide as the infant son began to form within the dust in the vortex surrounding it began to stick together forming larger and larger rocks which eventually became rounded by their own gravity and then nuclear fusion began at the heart of the young star the son was ready and the solar system was formed the Sun emitted plumes of solar energy which dispersed most of the leftover batter around it which collected to form the gas giants meanwhile dozens of planetary embryos were orbiting the inner solar system colliding with each other eventually sticking together under intense pressure forming the four rocky planets these early planets cleared their orbital paths sweeping up most of the dust left behind spiraling inwards on their planetary disks this process is known as accretion earth was formed in this manner but it was far from the Oasis we know it as today it continued to grow through collisions until its interior was so hot that heavier metals began sinking towards the core forming Earth's internal layered structure and its magnetic field at 10 million years old the earth had grown large enough and was ready to begin its journey currently nothing more than a fiery vision of hell it had entered the Hadean era the young solar system remained a highly hazardous place the planets were shuffling between each other as everything fell into position during this time a larger planet was migrating outwards the early Neptune and its gravity was displacing rocky material plunging the inner planets into chaos this period of intense collisions with asteroids is known as the late heavy bombardment a 300 million years spanning event of chaos and destruction which pulverized the planets of the solar system with regular apocalyptic impacts from asteroids while hell rain down from the sky of the young earth it rose from the interior to volcanic activity ravaged and reshaped the surface releasing volatile gases which drove away the early lighter elements left over by the solar nebula replacing them with an atmosphere of toxic greenhouse gases and yet even during this hellish period earth still had a familiar feature flowing water on his surface detrital zircons crystals some of the oldest materials on the planet estimated to be over 4.4 billion years old show evidence of having made contact with liquid water earth already had oceans only a hundred million years after it formed but these oceans were highly acidic and inhospitable but deep down below the surface far away from the Armageddon which was raging above lay something that we have discovered would have been instrumental for life to emerge deep sea hydrothermal vents much like underwater volcanoes these vents frequently erupted matter and minerals from the Earth's mantle which solidified creating shelters of warm mineral rich material even during the chaos of the Hadean era the framework for life on Earth was beginning to fall into place but how did earth get its water if it was a ball of burning rock well given the Earth's primordial conditions the water would have had to have come from elsewhere in the solar system perhaps from the icy meteorites and comets which formed much further away from the young sun's warmth which would have smashed into the planet and melted the chaos of the Hadean era was not forever eventually Earth's tectonic processes began to give the planet it's more familiar features volcanic activity changed the composition of the atmosphere reducing the quantity of methane and replacing it with carbon dioxide trapping much less heat under the atmospheric layer as the earth began to cool clouds formed above and something different now rain down from the ancient sky water every day for thousands of years it rained and this formed the Earth's oceans these oceans filled the space between the new contents which Mother Nature was carving out as the interior of the earth remained highly active but on the surface things were calming down earth was no longer the barren molten ball it formed us the late heavy bombardment was coming to an end as Neptune drifted out towards the edge of the solar system and the planet began to become more reminiscent of the vision of heaven we know as today lighting the way for a much more complicated phenomenon to arise now in my hand I have a fossil and fossils are interesting they are souvenirs that you can buy our most Natural History Museum's and they're quite cheap which is surprising if you think about what fossil actually is now also is an antique in fact more than that it's an ancient relic of a moment that happened hundreds of millions of years ago that has been frozen in time now when this animal hits a shellfish that would have emerged not too long after Malta cellulite emerged in the oceans dies it sinks to the bottom of the ocean and gradually layers of rocks start to build up on top of it and these layers over time apply pressure which creates an impression in the rocks now the body is very well preserved by these layers but over millions of years it starts to decompose and as it does minerals in the rocks replace the space left by the decomposing animal and by the time this process is complete you get a near-perfect impression made out of rock of the animal that once inhabited the space and this is important because we can analyze rocks and work out their age quite precisely using a process called radiometric dating and what we'll do is we'll look at the isotopes inside a piece of rock and these isotopes decay a very very consistent rain and so by looking at how much these isotopes have decayed you can work out very precisely how old the rock is and so we can find it animals like these little fossils and we can start to put together a sense of when and where we found them and gradually we can build up a 3d map with time taken into account of where and when life started to emerge on the earth and from that timeline we can start to find our place in all of it the name Archaean comes from the Greek word meaning beginning or origin it's a fitting name as it was in this era that the first life emerged on earth into a surface environment which could actually sustain it during this period the atmosphere lacked oxygen but liquid water was now abundant on the surface we don't know the exact conditions under which life began to emerge in this new world but nature does give us a clue fossilized records with which we can start to piece together this picture of Earth's first life the earliest traces of life ever discovered were found in northern Quebec while not fossils of life themselves these imprints showed what scientists believe are the remains of early biological life processes and these rocks could be as old as 4 billion years more and more we're finding evidence to suggest that life could have emerged below the surface of the earth during the Hadean period if it had remained deep enough away from the bombarded surface this has challenged our ideas on the resilience of life on the early earth and it is still debated by scientists today what it does mean though is that there is strong evidence that life was present and established at the latest around 3.8 billion years ago in recent years we have discovered microbial life in underwater vents that were present in the Hadean era which source their energy from the heat spewing out from the Earth's mantle and crucially not through the energy from the Sun as all life was thought to be once this means that life could have emerged far below the surface and away from the parched barren land above with no need for the Sun while we aren't sure exactly what it is about these vents that seems to support the emergence of life we know that at the time they would have been erupting precipitates of minerals and chemicals which were cooling into frozen tower-like formations and vents after enough time these towers of precipitate were rich enough for complex carbon chemistry to take place and within these towers the first simple cellular life emerged on earth in 2016 a study was conducted to determine the genes that would have been present in the last common Universal ancestor of all living organisms on earth ie the top of the family tree and the root of this vast diverse living world we see today over three hundred and fifty five genes were identified well we don't know exactly the kind of organism that would have evolved here we know it would have been anaerobic and hydrogen dependent thriving in her environments with high amounts of nitrogen and carbon dioxide the conditions of the earth moving into the Archaean era over time these cells left their vents and harnessed the ability to move towards the Sun and some cells began emerging with random optimizations which enabled them to survive through the process of natural selection these better suited cells began to form colonies in the light sticking together using the first proteins and interacting with each other to form more complex colonies and structures eventually some cells harnessed the ability to use their environment to extract nutrients and the first fungi was born the Archaean period was limited to single-celled organisms which lacked new key I called prokaryotes these organisms are believed to have emerged in a form of bacteria and archaea and within a few hundred million years life had moved out of the oceans and was starting to survive in shallow waters on land in now the somewhat more familiar climate above over vast periods of time these single-celled organisms evolved into more complicated types of life the first nuclei were formed and then the first algae emerged gradually neutralizing the Earth's oceans making them much less acidic and more habitable to the more sophisticated forms of life meanwhile photosynthetic cyanobacteria began replacing the carbon dioxide and methane rich atmosphere with oxygen enabling new photosynthetic life and paving the way for the first multicellular plants and microscopic creatures billions of years later earth was now an oasis it survived the chaos of the early solar system it had escaped the clutches of the Hadean era and life had now emerged and embedded itself in the fabric of the planet turning it into a vision of heaven now obviously knowing when life emerged helps us because we can match that to the various periods we know the earth has been through and we can start to deduce what conditions life emerged under but it is only half the story knowing when life emerged doesn't tell us how it doesn't tell us the prerequisites that were required for the first simple cellular life to emerge and that is a big question because how on a ball of molten rock that is floating around space lifelessly do you get life and from that how do you get sentient life that's aware of its own existence that builds things and colonizes it's a huge question and to understand it is to understand us and the science and chemistry of the world we still don't know exactly what happened in those vents to give rise to life from non-life but what we do know is that it probably wasn't a single event scientists believe that a long combination of complex chemical reactions gradually added features to molecules eventually enabling the process we know as abiogenesis to occur the transition of nonliving matter to living matter through complicated carbon chemistry while there is no single agreed scientific model many plausible theories share some commonalities we believe that the process of life began with small groups of atoms called molecules eventually assembling themselves into molecular systems under the conditions of Earth's deep active ocean floor scientists have pinpointed the carbon hydrogen molecule methyl Adeem radical as a key component in this process which would need to be energized either by the warmth of hydrothermal vents saw the ultraviolet light of the Sun with an accumulation of features and abilities such as self-assembly cell division and self cloning these systems would have become biological polymers molecular systems performing biological processes after this evolution as we know it today would have begun as these polymers reproduce themselves mutations and inconsistent if the process would occur the largest cellular organisms that were best suited to their environment based on their random mutations prevailed evolving into things like acids proteins and carbohydrates eventually these building blocks form the first complex cellular life which from there over billions of years gave rise to multicellular organisms entire systemic colonies of atoms in colonies of molecules in colonies of polymers in colonies of cells arranging themselves into shapes and formations that allowed them to navigate their environment store energy and grow and reproduce entire full-scale copies of these systems most studies and experiments suggest that life emerged and evolved in a hot environment under conditions toxic and inhospitable to life the day it is also possible that life may have emerged from scratch more than once in different places and at different times if the earliest fossils we have discovered really are of four billion years old then it is likely that the planet would have been neutralized several times over during the chaos of the late heavy bombardment between catastrophic collisions there would have been windows of opportunity for the emergence of life only for it to be destroyed over again but if life did in fact emerge more than once than the resilience of life and the speed at which it evolves throws up a myriad of different scientific and philosophical questions about life on our planet and life beyond it abiogenesis is a credible hypothesis for how the first life emerged on this planet but it isn't really the only possibility an alternate idea is that life or son life at least did not begin on this planet but in our neighboring regions and was transported here by debris in huge collisions where it made its new home this idea is called panspermia and it is the hypothesis which assumes that not only is life common throughout the universe but its place of origin does not have to be the same as its place of evolution it sounds like a crazy idea but given the vastness of space it may well be occurring somewhere out there if not within our solar system the main hypothesized method for pants Permian life is that some microscopic life forms can become trapped in debris which is displaced after a significant impact such as a massive asteroid collision or collision with another planetary embryo if the debris is dislodged in a large enough chunk to incubate the microorganisms inside of it and is ejected into space with enough force then it is thought that some types of simple life could survive the effects of space traveling dormant for years or maybe even longer if the debris landed in a particularly well-suited interplanetary environment for example a large body of water then it is possible that these space traveling microbes could wake up and begin dividing and expanding in their new environment evolving into life on this new planet but then life is fragile what kind of simple microorganism could survive the unfiltered rays of stars and the icy blackness of space for years at a time well most microbes would have no chance in space but certain types called extremophiles microbes could survive in much more challenging conditions than most other life bacillus bacteria found in Morocco is one such kind of extrema file the microbe can withstand extreme temperatures and one study has shown that it's endospores can survive being heated to over 420 degrees Celsius let under 800 degrees Fahrenheit if extreme life forms like these are emerging on this planet imagine what could be evolving elsewhere it's easy to see why some scientists believe that panspermia could be a plausible hypothesis for the emergence of life elsewhere in the universe but what about for our solar system it seems the only thing that would have been able to disperse enough material for panspermia to occur in our solar system's history would be the late heavy bombardment and the violence of the early solar system but of course we don't see any evidence of the transition of life from Earth to anywhere else in the solar system after all we are a solitary blue speck in an otherwise desolate and silent expanse and during the Cataclysm four billion years ago earth was nowhere near the habitable environment for life is today but what if earth was not the source of the early life here but the destination what if life emerged on another planet and the violence of the late heavy bombardment distributed it throughout the solar system it's a remote possibility but if panspermia is the correct hypothesis for how life began on earth then where else in this system of inhospitable planets could life have emerged as humans we tend to associate the first life on earth as being very particular it required hundreds of millions of years of evolution under sustained conditions there as of yet haven't been found anywhere else but the earth but then if the discoveries we made in Quebec really are four billion years old then that would mean that life would have had to emerged almost straight after earth goddess ocean is literally within a few million years and that has some serious implications for our ideas of extraterrestrial life if life emerges that quickly then Earth may not be the first place in the solar system where it emerged based on our current models of the solar system we believe that Earth may not have been the first blue planet there was another flourishing and thriving as the young Hadean earth was being smashed to pieces and it was Mars Mars is red coloring makes it quite an iconic site in the solar system and so it's hard to imagine it any other way but billions of years ago Mars had oceans flowing on a surface we know this because the remains of these flows of water are ingrained on the surface we see River formations waterfalls lake beds and loads of other indications that Mars once had similar conditions to those that we see on earth today but the crucial thing we have found would move some probes to orbit the red planet where evidence of precipitous from hydrothermal vents much like the earth Mars most likely had these vents on his ocean floors bubbling up into the sea these would have been very similar to Earth's and if the discoveries made in cubic do indeed indicate that life emerged almost straightaway after the oceans formed on earth then there is a grounded reasonable as scientifically sound possibility that Mars once had its own awakening of on the planet all the ingredients for life were present on Mars and the conditions would have been optimal during the late heavy bombardment while it's difficult to tell the damage that was done to Earth by the bombardment due to its surface conditions at the time we approximate that on Mars about 1/3 of the Martian surface was completely destroyed not only would this have meant that Mars is life bearing properties survived the Cataclysm but if life existed on the part of the red planet that was struck by meteorites then there is a slim chance that this life could have been engrained in material that was flung out into space this would have occurred around the time life began to emerge on this planet so while the possibility is admittedly a highly remote one the coinciding time periods do make you wonder even if life on Earth is the result of abiogenesis panspermia is still a plausible hypothesis for the spreading of life around the galaxy different systems will have different stories and perhaps somewhere out there life has emerged on one world and now that same life thrives on other worlds [Music] as a hypothesis panspermia tends to focus on how life may be transported between host planets as opposed to the prerequisites for the emergence of life itself and so for that reason because we haven't explored the solar system thoroughly enough until we find a separate contrasting source of life somewhere out there the ideas and potential of panspermia will remain a mystery [Music] eventually Mars lost his habitable conditions it couldn't keep his magnetic field active due to its size and was unable to resist the onslaught of the sun's glare when its protective atmosphere was stripped away is oceans dried up and surface froze Mars became the desert planet we know it as today and the perfect reminder that habitability is not forever five billion years from now in the distant future earth will follow the same doomed path that at the mercy of the Sun when the star has entered the dining stage of its life and expanded to become a red giant it's vastly increased radiating surface was scorched this once illustrious planet returning it to the burning barren wasteland it was during the Hadean era in the end everything that has ever lived and died on this earth will be reduced to talk about which he came from dust the solar system will enter his final age of habitability as the distant moons enjoy warmer climates at both sunlight but after that age has passed the inner planets will be no more than scorched balls of lifeless molten rock and the outer planets will remain cold and hairless the solar system will return to the silent tips born out of everything you have ever done everything that has ever happened all of human history they will all be gone swallowed back into the great fires of the universe and our Sun and the system that surrounds it will become just another silent speck in our galaxy life is what gives the universe value and majesty creation is meaningless without comprehension from those first bacterial cells in the hydrothermal vents all those eons ago life has played out on the planet in an unendingly complex tapestry and while it may not be over yet one day all of it will be reduced to atoms floating around meaninglessly in space earth is a success story built upon chance fate and natural selection we can only hope that the phenomenal process which created us and that we are still struggling to comprehend life is in effect elsewhere in the universe because with billions of light years a vast unexplored domain in the night sky having nothing around to appreciate and understand it after we have vanished it just seems like a waste [Music] you [Music]

Channel: SEA

Views: 423,987

Keywords: Sea 1997, Sea1997, Sea, 1997, Space, OOTW, Out of this world, astronomy, science, earth, first life, hadean era, archean era, late heavy bombardment, hydrothermal vents, prokaryotic cell, solar system, abiogenesis, panspermia, mars, documentary, first life on earth, first life forms, bacteria, first species, early life on earth, 3 billion years ago, earth 4 billion years ago, how was earth formed, how did life begin on earth, molecules

Id: K7C3NgtqcTM

Length: 26min 34sec (1594 seconds)

Published: Fri Sep 13 2019