[Music] more than 4.5 billion years ago the Milky Way galaxy collided with a nearby dwarf galaxy this encounter hastened the formation of stars our solar system is a part of the Milky Way galaxy within the solar system material circulation had been progressing [Music] the water component from the outer region evaporated to make materials try [Music] through this process particles were zonally distributed depending on their water content the bipolar flow stopped and with it material circulation some regions around the Sun with high particle density appeared within these regions collisions frequently occurred small particles gradually grew to become planetesimals planetesimals continued colliding with smaller particles and other planetesimals eventually growing to planets such as the earth [Music] [Music] a number of planets were moving in the same orbit [Music] the early Earth collided with a smaller mars-sized planet [Music] debris from this impact eventually came to form our moon [Music] the earth-moon system as we know it today was in place [Music] countless planetesimals and icy planets bombarded the early dry earth due to the bombarding water enriched planetesimals the earth became enveloped by an ocean atmosphere system [Music] water vapor in the atmosphere produced rain forming an ocean the atmospheric pressure gradually decreased the carbon dioxide rich atmosphere transitioned into a co2 ocean covering the water ocean carbon dioxide also combined with rock components and was transported to the bottom of the ocean through weathering and erosion at this time the ocean was still toxic with a high salinity and an overabundance of metals it was too toxic to support life upwelling mantle displaced the oceanic plates above uplift of the plate by mantle convection caused horizontal slippage due to the weight of the plate this is plate tectonics in action the oceanic plate subducting under the lighter continental plate [Music] weathered sediments neutralized the ultra acidic ocean heavy metals settled out and became fixed as deposits at the mid-ocean ridge these deposits were transported through plate tectonics into the deep mantle [Music] gradually the ocean became a habitable environment by 4.2 billion years ago a liquid core formed in the center of the earth convection within the liquid core created a strong magnetic field surrounding the earth this geomagnetic field shields the Earth's surface from cosmic rays the Earth's surface was nearing readiness for life [Music] the early Earth when the atmosphere prevented sunlight from reaching the surface primitive life was about to emerge underground in the cave of a geyser [Music] uranium ore emitted large amounts of radiation creating a diverse range of materials and eventually producing the early building blocks of life water boiled and rose up to the surface and the surface water flowed back down into the natural nuclear reactor the temperature of the geyser water remained below 100 degrees protecting the newly formed biomolecules the underground environment was reductive while the surface environment oxidizing these conditions were necessary to synthesize biomolecules [Music] in the Earth's hidden 'ya tidal forces were much more pronounced than they are today even Lakes had significant urban flow of water creating wet and dry cycles these wet and dry cycles were one of the most crucial factors in producing the building blocks of life [Music] fatty acids came together encasing the proto life molecules polymerization progressed under the wet and dry cycles eventually protein like basic materials that could act as catalysts were produced these molecules circulated between the geyser cave and the surface environment the interactions of these materials led to more complex biomolecules proto RNA combined with enzyme like basic materials and evolved into ribozymes which had the ability to replicate themselves this laid the groundwork for life to reproduce finally these molecules were enclosed within lipid membranes forming primitive proto cellular life [Music] this was the beginning of life [Music] [Music] [Music] the Earth's plate tectonics which had begun with the creation of its ocean eventually destroyed its primordial continent and subsumed it to the deep mantle by four billion years ago the mother continent had disappeared leaving life on the margins of a fragmented landmass [Music] inside the earth a dramatic change was about to begin [Music] the subducted primordial continent descended toward the core-mantle boundary the wealth of radioactive elements in the primordial continent caused the uppermost part of the core to melt by 4.2 billion years ago the newly-created liquid outer core was strengthening the Earth's magnetic field protecting the surface environment against solar winds and cosmic rays [Music] as a result life could exist on the surface environment [Music] the supply of energy and nutrients through material circulation is necessary for life the essential mechanism to maintain life is an endless flow of electrons the first pro to life couldn't survive very far from the nuclear geyser due to insufficient energy mutations however allowed life to evolve [Music] the more resilient life-forms were able to adapt and survive in harsh environments [Music] this second stage of proto life evolved to make use of the sunlight available on the Earth's surface [Music] they developed a metabolism that converted light energy into electrochemical energy moreover they used sugars to store energy for the sunless night hours the source of energy for life on earth shifted from nuclear geysers to the Sun [Music] around 4.1 billion years ago the ocean was still extremely toxic killing off most of the proto life-forms within it nevertheless some proto life-forms survived the extreme environment [Music] they developed protective mechanisms to prevent the metallic ions in the ocean water from entering their protocells [Music] this proto life began coalescing into larger and more complex forms [Music] modern life-forms use only twenty kinds of amino acids this means our ancestors that used the same amino acids were the ones that survived the mass extinction [Music] evolution walks a perilous tightrope between continuing and ending unstable RNA evolved through ionizing radiation into more durable DNA making it possible to reliably pass information across generations and the third stage of proto life was born this was the beginning of prokaryotic organisms the ancestors of today's archaea and bacteria [Music] oxygen when unbound to any other material can be toxic to life because oxygen destroys the reductive life body [Music] therefore the first photosynthetic organisms would have been anaerobic microbes which produced no oxygen life however adapted taking advantage of oxygen as a valuable source of additional energy [Music] this development resulted in the appearance of cyanobacteria cyanobacteria produced oxygen which crystallized into felsic iron-bearing oxide reducing the iron content of the ocean still the ocean was five times as saline as it is today as the Earth's interior cooled old slabs of the primordial crust resting at the bottom of the upper mantle fell into the lower mantle meanwhile numerous mantle plumes ascended from the lower mantle into the upper mantle this phenomenon is known as mantle overturn mantle plumes pushed the basaltic crust upward generating landmass this created shallow marine environments penetrated by sunlight which allowed the cyanobacteria to flourish the oxygen produced by the cyanobacteria gradually altered the Earth's atmosphere [Music] on the ocean floor ferric and ferrous iron were accumulating in the form of hematite and magnetite creating a massive banded iron formation by 2.5 billion years ago the remaining banded iron formation was a few kilometers sic this rapid decrease in iron content changed the color of the ocean to a familiar blue life began to change the surface environment such is the coevolution of the earth and its inhabitants this was an important step in life on Earth's long journey towards civilization a collision between the Milky Way and a nearby dwarf galaxy produced countless glowing stars within a few thousand years some of these stars ended in supernova explosions a myriad of cosmic rays from the supernova deteriorated the sun's heliosphere and bombarded the earth [Music] these cosmic rays help generate cloud condensation nuclei which produced more and more clouds until the earth was completely blanketed with them the thick cloud cover prevented sunlight from reaching the surface of the earth the earth underwent a global glaciation event known as the snowball earth this caused another global mass extinction [Music] but once again some life survived yet another difficult period beneath the ice sheet tiny life was protected by the Earth's massive circulating system [Music] and the earth is similarly held in place by the solar system and the expansive universe life is but one part of an enormous system the prokaryotes survived the snowball earth evolving into more complex life such as endosymbiotic systems living together inside cells they formed mitochondria and chloroplasts which allowed them to get more energy from oxygen [Music] a single prokaryote body could contain thousands of mitochondria a nuclear membrane formed protecting DNA from the oxygen dense ocean water DNA strands grew longer retaining ever more genetic information life evolved into more diverse and complex organisms at long last the eukaryotes appeared the eukaryotes grew a million times larger than the prokaryotes in theory everything inevitably falls into disorder [Music] and yet life is orderly and increasingly complex life seems to continue evolving undeterred by universal entropy plate tectonics caused small developing continents to assemble into a single supercontinent called nuna as nuna formed its burgeoning landmass provided cyanobacteria with an expanding habitat in its lakes rivers wetlands and estuaries cyanobacteria produces free oxygen through photosynthesis at that time however most of the free oxygen produced was consumed in decomposing dead cyanobacteria so very little free oxygen accumulated in the atmosphere on land however dead cyanobacteria got buried under sediments so oxygen that would have broken down their bodies instead ended up in the atmosphere the presence of a large landmass helped increase the amount of oxygen in the atmosphere as the total land area on the surface of the earth increased so too did atmospheric oxygen levels dramatically [Music] over time the nuna supercontinent broke up into smaller continents but once again plate techtonics reassembled a supercontinent this one called Rodinia in equator region slabs of oceanic plates subducted under continental plates gradually accumulated in the mantle transition zone eventually these slabs fell down into the core the slabs cooled the outer core changing the flow of electricity within as a result the cores dipole magnetic field transformed into a weaker quadrupole magnetic field the Milky Way galaxy collided with a dwarf galaxy and underwent to transition into starburst conditions over time these newly produced stars ended in supernova explosions bombarding the earth with cosmic rays the earth with its weak quadrupole magnetic field was heavily affected clouds covered the entire earth and ice covered its surface a series of supernova explosions occurred long periods of extreme heat were punctuated by shorter periods of extreme cold in the extremely cold periods oxygen in the atmosphere fell to Archaean Eon levels causing mass extinctions these mass extinctions however created great opportunities for life to evolve into something completely new repeated in fluxes of cosmic rays and drastic fluctuations in oxygen levels these environmental changes caused genetic mutations that accelerated the appearance of new species [Music] the starburst period ended and the Earth's core reverted to a stronger dipole magnetic field ongoing photosynthesis returned the oxygen in the atmosphere to previous levels meanwhile the Inner Earth was gradually cooling down when the Inner Earth is hot enough the components of water trapped in minerals in the oceanic plates are released to the surface environment and the sea water level is unaffected [Music] however once the mantle temperature drops below 650 degrees Celsius minerals carry these water components down into the upper mantle meanwhile on the surface deprived of the components of water sea levels gradually decrease this is known as the leaking earth phenomena which is inevitable on a cooling planet this leaking effect moved three percent of all seawater into the deeper mantle sea level dropped by 600 meters as a result surface land areas grew as did continental shelf areas receiving sunlight a habitat for future life on earth was being created rivers carried nutrients from the inlands down to the continental shelves and the additional landmass significantly accelerated the build-up of oxygen in the atmosphere these processes set the stage for an explosive evolution of life-forms [Music] [Music] extreme climate changes continued putting life on a path to new evolutional stages for survival life evolved with prokaryotes and eukaryotes living together as ever larger symbiotic organisms compensating for each other's shortcomings and thriving as a whole this greatly expanded the possibilities for forms of life [Music] life forms grew to 1 million times the size of eukaryotes and 1 trillion times the size of prokaryotes the appearance of multicellular life was a critical leap for evolution [Music] another glaciation period came and life suffered a mass extinction with time this glaciation also passed and the global climate gradually warmed phosphorus and other materials essential for life circulated through the climate system and accumulated in the oceans the animals of the Ediacaran period appeared at this time dick and Sonia are iconic among the Ediacaran fauna some grew to over 1 metre in length they were soft bodied creatures with no shell or skeleton [Music] they probably lived in warm shallow marine environments around the Rodinia supercontinent [Music] the supply of nutrients from the land was ever-increasing as was atmospheric oxygen the amount of ferrous iron in the oceans increased the ferrous iron oxidized once again creating large bands of iron phosphorus and calcium levels in the ocean increased life evolved to use these elements becoming animals with bones and shells for example the calcium helped protect micro dikteon from other animals their bodies used calcium to form a covering of hard scales [Music] life evolves to survive making use of the elements in its environment and the Earth's environment alters the shapes of life [Music] the earth entered another period of climactic instability the earth alternated between periods of extreme heat and extreme cold for tens of millions of years these severe changes killed off the Ediacaran fauna nevertheless new species were about to appear radiation from inside the earth plays a significant role in the evolution of life a continental rift is a place where a continent breaks open to expose erupting magma and radioactive elements radiation hastens the creation of new species and new branches in the Tree of Life this is stem evolution creating new species at continental rifts life evolved separately on each small continent when small continents recombined their life forms crossbred [Music] different crossbreeding 'he's created new forms of life variation thrived this is crown evolution continental collisions created more diverse surface environments bays and gulfs on large continents were especially well supplied with nutrients from upstream making use of these nutrients Cambrian era life-forms diversified much more quickly [Music] the Cambrian explosion created some 35 new phyla these phyla became the foundation for the types of plans and animals we see today [Music] there are three main ways that life evolved mass extinctions that eradicated many species stem evolution that hastened genetic mutations when continents broke apart and crown evolution that hastened bio diversification when continents collided so the evolution of life is inextricably linked to environmental changes due to universal factors and continents assembling together and breaking apart [Music] the ocean was more than five times as saline as it is today 600 million years ago the ocean gradually became less salty salt from seawater was relocated to the land in the form of rock salt decreasing sea levels made this possible through more exposed land even if seawater rose again high enough to reclaim the rock salt most of it had become inaccessible encased in sediments the decrease in seawater salinity made the ocean more hospitable to diverse life-forms estuaries and open seas welcomed new life with increasing atmospheric oxygen levels an ozone layer formed in the Earth's upper atmosphere the ozone layer absorbs ultraviolet radiation from the Sun the land was becoming a more habitable environment [Music] [Music] Algie was the first life-form to transition out of the water onto the challenging land environment this is why algae evolved before animals did when insects appeared they Co evolved together with plants appearing during the Cambrian explosion fish were the first of the vertebrates animals with backbones fish are the oldest vertebrate ancestors of us humans as fish continued to evolve xeo Steger appeared the ancestor of amphibians [Music] plants flourished producing free oxygen through photosynthesis providing the atmosphere with 1.5 times as much oxygen as it has today long after the remains of these plants would become sedimentary coal that coal would help fuel the remarkable breakthroughs for human civilization that started with the Industrial Revolution [Music] next vertebrates equipped with lungs appeared and made their way onto land [Music] the tree of life evolved branching from fish to amphibians to reptiles and then dinosaurs and mammals and eventually to humans this guy hasn't found out about all that just yet [Music] [Music] the solar system collided with the Dark Nebula as the solar system passed through the nebula the earth was bombarded with cosmic rays the earth entered yet another frozen age plants were affected first dramatically reducing the oxygen they supplied to the atmosphere the surface environment reverted to an anaerobic state like during the Archean period the lack of oxygen killed off most species of amphibians reptiles and insects life managed to continue evolving but faced another big challenge [Music] untouched by the evolutionary changes on the Earth's surface anaerobic microorganisms had been thriving in oxygen-poor underground environments the new oxygen-poor surface environment allowed them to re-emerge on land and in oceans their native habitat expanded across the globe as oxygen levels rose again these microorganisms evolved to adapt to the new environmental conditions setting the stage for another phase of evolution the emergence of new creatures that would evolve into humans was close at hand you [Music] [Music] on the supercontinent Pangea mammals and reptiles appeared and started evolving under a warm climate [Music] while reptiles diversified into many varieties mammals remained nocturnal rat sized animals the mammals were in the shadows [Music] [Music] with the appearance of dinosaurs reptiles entered for Golden Age [Music] dinosaurs prevailed against many other animal species and won the struggle for survival [Music] high-radiation magma is produced when a continent is split apart and this is where stem evolution occurs due to induced mutation dinosaurs were at the pinnacle of their ecosystems [Music] [Music] the pieces of northern Pangaea that had split later rejoined this caused crown evolution amalgamation of continents brings the hybridization of life and new species spread out to other continents [Music] [Music] dinosaurs flourished all over the world in the plant world angiosperms with advanced reproductive capacities appeared angiosperms utilize animals to help with pollination and thus flourished on the other hand the habitat of gymnosperms was reduced primates the ancestors of humans appeared at the rift of the Gondwana super continent via stem evolution new species appeared among the rodents such as rats [Music] with time Gondwana split into South America and Africa after South America was isolated the primates there evolved into the new world monkeys [Music] on the African continent the primates evolved into the old-world monkeys after the Indian subcontinent split off from Antarctica primates on this continent evolved into the lorises primates evolved independently on each continent and in this way many species of primate appeared [Music] a large-scale Pacific super-plume pushed the Pacific plate up and raised the sea level lowlands fell below sea level and the total land area decreased rising sea-levels segmented the continent providing isolated environments for individualized morphological evolution [Music] a universe scale event had changed Earth's surface environment the solar system collided with a Dark Nebula the earth was entirely covered by clouds global cooling progressed catastrophic Li damaging ecosystems finally a meteorite ten kilometers across fell on the Yucatan Peninsula this event was the final trigger to cause the mass extinction of dinosaurs the fate of the Earth's life is deeply connected to the events in the universe universe scale events can cause global cooling and mass extinctions [Music] moreover galactic cosmic rays directly affect the DNA that carries the blueprints of life cosmic rays cause mutations which promote evolution all aspects of life on the earth are thus influenced by universe scale events finally the dinosaurs that had flourished went extinct [Music] along the African Rift Valley explosive volcanic activity continued and peculiar magma containing abundant radioactive elements erupted old world monkeys a new clade of primates appeared there they're thought to be our remote ancestors [Music] about 4.5 billion years have passed since the birth of the earth large fluctuations in terrestrial environments have occurred repeatedly a never-ending cycle of life and death finally human beings appeared this was the onset of the humans Oh Akhil humans have a unique set of genetic regions called human accelerated regions or har s and these regions differentiate humans from other animals humans developed enlarged brains that enable them to gain language capabilities they also gained the abilities to think to be conscious to remember and to imagine the brain volume of human beings has discontinuously increased in three stages the growth of brain volume seems to be synchronized with large-scale volcanic eruptions this indicates that the increase in brain volume is caused by stem evolution driven by hi our magma [Music] about 1 million two hundred thousand years ago humans started moving out of the African continent the last common female ancestor who left the African continent 200,000 years ago is called mitochondrial Eve descendants of mitochondrial Eve entered North America and Central America fifteen thousand years ago ten thousand years ago further descendents reached the southern tip of South America they had spread all over the world since then an epical advance of human civilization has taken place [Music] humans invented agriculture and livestock production with these methods a stable food supply became possible human populations increased rapidly [Music] various occupational specializations arose people began to barter and trade to enable effective bartering cities formed with time small cities developed into small city states with currencies economies laws courts and police finally the four great civilizations of the world appeared along large rivers where food productivity is higher than in other regions conflicts in fighting over territory occurred between civilizations [Music] to avoid fighting religions spread to replace governance by royal families entrenched through inheritance with time national leaders came to be elected by voters modern democratic nations appeared democracy is a social form that grants freedom equality and basic human rights the Industrial Revolution began in Great Britain after the Principia by Isaac Newton was published new technologies established or applied based on scientific knowledge dramatically changed human society the invention of the steam locomotive enabled transportation of goods by railway the invention of cars and airplanes enabled us to travel long distances easily [Music] human society entered the age of never-before-seen abundance [Music] however war occurred incessantly sometimes irreversible tragedy was caused by the misapplication of scientific knowledge the information revolution arose following the invention of computers it enabled human beings to explore the universe as was symbolized by the Apollo program and the invention of the internet led to a new era in which people across the world can connect with each other in an instant [Music] out of contrition over past Wars the birth of a unified world nation is coming to be realized in 1993 the EU was formed as a unified state in Europe where Wars had recurred most frequently in other areas similar Federation's have been emerging bringing us closer to the birth of a unified world nation [Music] within the scope of Earth's history the human azoic era is very short however it is humans entire history unfolding within the context of the Earth's history biologically human beings are just one species of animal however we are essentially different from other animals because of our evolved brains [Music] what else lies ahead for human beings [Music] you [Music] [Music] human activities have been dependent on fossil fuel fossil fuel was produced and accumulated through Earth's history over billions of years we are now using up these fuels at a furious pace the amount of fossil fuel remaining is expected to decrease sharply after 2020 it was once assumed that fossil fuel would one out by 2100 however due to the shale gas revolution this depletion will be delayed 100 years progress in medical technology and the intake of nutritious meals has caused explosive population growth as a result serious food shortages will occur around 2020 these will mark the beginning of the era of 3 billion refugees however the world's population is expected to decrease to 5 billion by 2100 after peaking at 10 billion in 2050 until 2050 the increasing population will continue to cause serious environmental contamination numerous global challenges will amplify the anxiety within human societies what does the future of human beings hold [Music] in the field of science innovative technologies will be developed at an accelerated pace humans will build a space base on the moon to prepare for exploration of our solar systems planets artificially intelligent robots will be involved in space exploration assisting humans in their tasks in the near future self-replicating robots will appear and will evolve beyond humans limits these artificial life-forms will gradually travel out into the galaxy moreover new technology enabling us to go into different dimensions will be developed humans must become able to recognize the world beyond space and time eventually the role of human beings will be finished that will be the end of the human is Owen era this scenario may be the inevitable result of the strategy of life's evolution because in the future the earth will face more upheavals than ever before in its history centering on Asia all continents will gather to form the supercontinent Amasia [Music] plants consume atmospheric co2 to fix carbon in their bodies dead plants made of fixed carbon are covered by sediment this process plays a role in reducing atmospheric co2 the appearance of the supercontinent Amasia will lead to an increase in the land area that can fix carbon more plants on a larger supercontinent reduce more atmospheric co2 the amount of co2 will decrease to one tenth of the present level the c4 plants requiring higher concentrations of co2 will go extinct as a result other animals that rely on the c4 plants for food will be affected seawater has been decreasing for the past six hundred million years as it has been transported into the mantle in the form of hydras minerals finally mid-oceanic ridges form summits above the seawater water cannot be taken into the crust as a lubricant anymore and plate tectonics is terminated this is the fate of a cooling planet volcanic activity along these subduction zone stops upheaval of the mountains stops the earth suffers severe environmental changes due to erosion [Music] subducted cold plates do not go down to the bottom of the mantle the outer core is not cooled down anymore and the geomagnetic field disappears [Music] Earth's atmosphere is removed by the solar wind at this point in time large multicellular animals living in the surface environment go extinct when the ocean disappears animals that survived in the ocean will also die [Music] finally all the Earth's life disappears the heating up of the solar surface increases the Earth's surface temperature to 500 degrees Celsius the earth becomes a Venus like planet the andromeda galaxy collides with our Milky Way galaxy because of this collision the birth rate of stars increases with time those stars undergo supernova explosions intense galactic cosmic rays rain on the earth the expanding Sun will swallow the earth this is the day when the planet Earth that gave birth to life will disappear from the universe by that time the Earth's life will have reached other galaxies as self-replicating artificial life in a different form