What was the Earth like 3 Billion Years Ago ? | History of the Earth Documentary

foreign the history of the earth begins 4.6 billion years ago at that time everything was different from what we know today in the beginning the Earth seemed strange and unknown and yet it will become so welcoming that it will allow life to develop and humans to settle there permanently [Music] the world around us formed how did it evolve to become the Earth as we know it today [Music] dear Traveler good morning through four videos we embark on an exceptional Journey retracing the history of the earth since its birth to dive back into the heart of our planet at the beginning of its formation and throughout its evolution today we start the second chapter previously we have related its Adventure from its accretion until three billion years ago [Music] until 485 million years ago every planet has a history this is the history of the Earth but before you go don't forget to like the video and subscribe to the channel so you don't miss anything thank you and have a nice trip [Music] the pongola glaciation is the first ice age in Earth's history beginning 2.9 billion years ago an ice age is characterized by the existence of at least one ice sheet and is associated with a significant lowering of the global average ocean level an ice sheet is a continental ice cap formed from snow precipitation covering at least 50 000 square kilometers or twenty thousand square miles over a maximum thickness of a few kilometers or a few miles ice ages are related to plate tectonics when one or more continents drift to Polar conditions snow accumulates in the summer the origini that is to say the formation of reliefs favors the appearance of new fractured rocks in the open air which can be brought to undergo strong alterations and consequently a great consumption of CO2 from the atmosphere leading to a decrease of the Greenhouse Effect and the temperature at the surface of the planet the increase of the Albedo a reflective power of the earth generates a runaway phenomenon of glaciation and once half of the surface of the Earth begins to be frozen in white nothing can counter a total freeze this phenomenon leads the Earth to a snowball appearance [Music] 2.7 billion years ago the formation of a new supercontinent begins kennerland it includes the future parts of laurentia baltica Western Australia and Kalahari a few million years earlier magmatic outpouring was under the ocean begin and reach their highest peak with an eruption of comatites volcanic arcs are accompanied by upwelling of rocks from the mantle followed by orogenic deformation installation of granitoids stabilization of the lithosphere and finally collision with other creightons It Is by accumulating all these phenomena that the supercontinent kennerland take shape above the sea level 2.5 billion years ago the phenomenon of plate tectonics will take a turning point in the history of the Earth's geology until then two types of plate movement were operating horizontal and vertical the latter is explained by subduction a geological phenomenon that occurs when rocks have different densities a massive unit such as Ultra basic lavas of the comatite type is placed on a less dense unit such as the crust and literally sinks into the ladder involving a movement contrary to die a person as a result less dense rocks move up the sides of the inverted diameter the sagduction creates depressions in the middle of the plates and contributes to the accumulation of sedimentary deposits at this time the composition of the mantle evolves and the formation of comatite slows down the density of the basaltic masses being too low to provoke subduction vertical tectonics ends and only horizontal tectonics will last until our time a heavy and unbreathable atmosphere rains on the Earth the planet is in a transition phase during which the methane-producing microorganisms give way to photosynthetic organisms and release oxygen in large proportions the earth looks like Saturn's moon tight under a thick orange fog foreign the intense activity of cyanobacteria releases a large amount of oxygen into the sea water which then reaches the atmosphere the chemical evolution of the latter is certainly a major event but the ecological crisis that follows marks the history of the Earth the great oxidation is similar to a mass extinction that kills most of the organisms existing at the time for which oxygen was then toxic living things build structures based on carbon or on carbon compounds with a nitrogen group in both situations this refers to Assemblies of carbon atoms organisms that contribute to oxygenation draw their carbon from the CO2 molecules in the atmosphere and their energy from sunlight when a reaction of fixation of a carbon atom occurs it releases a molecule of dioxygen for cyanobacteria oxygen is therefore only a toxic waste product cyanobacteria through photosynthesis release a large amount of oxygen into their environment which then reaches the atmosphere the oxygen reacts first with the compounds present on the surface such as methane salt and iron minerals then the latter being at saturation it begins to accumulate in the atmosphere foreign the oxygen thus released is a poison for the living organisms present at the time since they are anaerobic organisms many organisms existing on Earth are killed the survivors in a first time develop mechanisms to protect themselves from oxygen then in a second time the organisms evolve into aerobic organisms today they are the majority since oxygen has become essential [Music] the increase in oxygen concentration provides a new opportunity for biological diversification and changes in the chemical interactions of rocks sand Clay and other geological substrates without the widespread availability of oxygen life was previously Limited the energy available to living organisms is now increasing as early as 2.4 billion years ago the earth enters what will remain one of the longest ice ages in its history the huronian glaciation owes its name to sedimentary formations of glacial origin found in North America in the Lake Huron region [Music] the entire surface of the Earth is covered with ice this Sudden Change in the climate of the planet is closely linked to the evolution of the composition of the atmosphere that occurred at this time with the appearance of life and the processes of photosynthesis prokaryotic bacteria release oxygen in large quantities this oxygen is able to oxidize the methane in the atmosphere which reduces its concentration methane being a powerful greenhouse gas its decrease triggers a drop in temperature at the same time the CO2 is trapped in the limestones in formation and its proportion in the atmosphere decreases the decrease in greenhouse gases causes a global cooling followed by a succession of ice ages 2.4 billion years ago the sun is 20 percent less powerful than today which contributes to the sharp decrease in temperature it is up to minus 50 degrees Celsius or minus 52 degrees Fahrenheit for several tens of thousands of years the water is Frozen the Albedo increases as the icy white areas reflect much more Cooling and freezing increase [Music] in the heart of the earth activity is in full swing the volcanoes emit CO2 which is stored under the ice at the slightest opportunity it is released into the atmosphere suddenly intensifying the greenhouse effect temperatures then rise to the surface a deglaciation occurs in a few tens of thousands of years during 300 million years the processes of glaciation and deglaciation will occur four times volcanism continues to produce carbon dioxide insignificant quantities and it slowly accumulates in the atmosphere the greenhouse effect becomes sufficient to warm the planet and melt the ice the decrease of the Albedo accelerates the process leading abruptly to the passage from an ice age to a tropical climate at the end of this huronian glaciation The Retreat of the glaciers triggers a massive erosion that disintegrates the silicates absorbs the excess CO2 and precipitates it into the oceans in the form of silicates the continents are denuded but the decrease in CO2 weakens the Greenhouse Effect and allows a return to more moderate temperatures [Music] the erosion phenomenon tends to bring the continental crust back to zero level everything that is in relief above sea level is eroded and alluvium is deposited in the marine environment contributing to sedimentary deposits conversely everything below sea level gradually settles until it rises again as a result of the accumulation of creightons over larger and larger land masses the oceans become deeper [Music] ire in the form of ferrous ions is present in the Primitive oceans in soluble form and green in color with the appearance of the first organisms photosynthesis and the production of oxygen the composition of the ocean evolves and so does the form of oceanic iron ferrous iron oxidizes into red ferric iron in this form iron is no longer soluble in water it precipitates and falls to the bottom of the oceans accumulating in the form of sediment until it becomes Rock during periods of glaciation which are not very favorable to the development of organisms the production of oxygen slows down or even stops the rock is then adorned with a less red layer with a ribbon-like appearance rather gray or greenish the iron having now precipitated it does not disturb the ocean which becomes much clearer the sunlight penetrates more intensely and photosynthesis takes place at greater depths organisms of a new type appear coccoid bacteria taking the form of spherules surrounded by a shell a kind of Plankton living on photosynthesis called phytoplankton [Music] taking advantage of a moderate climate this type of Plankton autotrophic towards carbon develops at its ease it gets its energy by photosynthesis [Music] too small to be visible to the naked eye it can appear on the surface of the water as a colored expanse if its organisms are present in sufficient quantity phytoplankton is a primary producer since its function is to transform inorganic matter such as CO2 mineral salts light or water into organic matter that will be used by other living organisms [Music] under the influence of plate tectonics a supercontinent slowly takes shape 2.2 billion years ago Colombia also known as Nuna this supercontinent was welded together during a long period of origin and collisions over 4 million years it includes most of the earth's land mass and is estimated to extend twelve thousand nine hundred kilometers or 8 000 miles from north to south and 4 800 kilometers or 3 000 miles at its widest until 1.8 billion years ago the Continental blocks move until they reach their final position the eastern coast of India is attached to Western North America South Australia is welded to western Canada the kratonic blocks of South America and West Africa are welded first during the transamazonian and a bernian Origins two million years later the capfall in Zimbabwe blocks collided along the Limpopo belt one million years later the final assembly takes place the North American Creighton suture the cola corellia volgo uralia and sarmatia Creighton's join to form baltica a Paleo continent the anavar and Aldon Creighton's connect the North and South Indian blocks join and finally the East and West blocks of the China Creighton weld together Colombia remains a super continent until 1.6 billion years ago when it begins its fragmentation [Music] the oxygen now available becomes a new source of energy much more efficient than fermentation the world of living things evolves and becomes more complex bacteria learn to use this element and respiration appears oxygen is particularly reactive and allows a better catabolism than an anaerobic conditions is it at this moment that cells with a nucleus appear the subject is still much debated the oldest microfossil indisputably eukaryotic is dated 1.45 billion years but recent discoveries have revealed traces of multicellular life that would date back to 2.1 billion years ago this discovery has not been refuted but some scientists dispute its interpretation we will place their appearance here in our chronology the development of new forms of cells is becoming more and more widespread these are the eukaryotic cells the term eukaryote covers all unicellular or multicellular organisms that have a nucleus and organelles such as an endoplasmic reticulum plastids and mitochondria the hole is delimited by membranes in contrast prokaryotic cells lack these components another element that differentiates eukaryotes and prokaryotes is the structure of their DNA strands the genetic material of eukaryotes is located in the nucleus in the form of linear strands that are compressed during cell division the chromosomes prokaryotic cells on the other hand have only one circular chromosome that forms a loop eukaryotic cells are larger on average a thousand times larger the first fossil traces are actriarchs spherical organic vesicles measuring from 20 to 100 micrometers these eukaryotes most certainly originated from bacteria and archaea but the process that led to this evolution is still a mystery biologists assume that cell compartmentalization would have appeared as a result of capture infusion mechanisms between prokaryotes and would have resulted in the formation of a eukaryotic cell this is why eukaryotic cells are larger than bacteria in 2008 a profusion of centimetric fossils similar to multi-cell eukaryotic organisms were found in Gabon near Francisville while the scientific Community thought that this form of life had appeared much later black Clays from the Francisville Basin which has not been tectonically deformed or metamorphically affected have revealed fossils of multicellular organisms within rocks belonging to a group of five harmoniously stacked formations nearly 400 fossils were discovered and the black clay layers these fossils measure from 7 to 120 millimeters in length from 5 to 70 millimeters in width and one to ten millimeters in thickness they can take the form of circular aggregates pirate ties or not in spite of their flat representation Colonial pleurocellular organisms are differentiated from bacterial mats by the presence of steroings which occur during the transformation of sterols during diagenesis sterols are properly related to the biosynthesis of eukaryotes the presence of these eukaryotes corresponds to a time when the oxygen content was still low between 0.1 and 1 of the current concentration of the atmosphere researchers believe that these are Assemblies of cells that communicated with each other and were capable of coordinated movements at this time 2.1 billion years ago multicellular organisms were not at their Peak but they were making a quiet entrance into the world of light they will spread and diversify more widely a little later appearance of eukaryotic cells is jointly linked to the appearance of compartmentalization within the cells themselves [Music] it is expressed by the presence inside the cell of various organelles and a nucleus that imprisons the genetic material two billion years ago the endosymbiosis of a protobacterium would have allowed the appearance of a particular organelle the mitochondrion during their evolution cells meet and interactions occur some cells absorb other cells if digestion does not occur the ingested organism reproduces within the host cell over time the bacterium no longer has autonomy and becomes an organelle endosymbiosis is defined by this type of Association when one of the partners lives inside the other and provides a benefit to all the cells anaerobic cells with a nucleus would have ingested bacteria capable of transforming the energy of certain molecules into energy that can be used for other reactions some of these absorb bacteria become machines allowing the production of energy for the cells the mitochondria these are the respiratory and energy centers of the cells foreign eight billion years ago and for a period of 1 billion years the earth isn't a period of relative calm its tectonic activity is stable as is its atmospheric environment biological evolution is slow due to low oxygen levels no glaciations have been recorded no major catastrophes no major Innovations this period is called the boring period and translated by the boring billion this appellation can be considered as unfair since the planet will undergo significant events in the billion years that will follow this period would have been marked by a particular Oceanic regime based on chemistry designated by the expression of Intermediate Ocean or Canfield ocean named after the scientists who postulated the existence of this ocean during the Great oxidation the oxygen produced oxidizes certain chemical elements present in the ocean such as iron but it is not present in sufficient quantity to oxygenate the entire aquatic environment in parallel the alteration and oxidation of Continental rocks are accentuated by the formation of supercontinence and the oxygenation of the atmosphere sulfate ions are then introduced in Mass into the oceans the Waters of the planet during a billion years are enriched in Sulfur but contain almost no iron and very little oxygen [Music] this new composition will have two effects on Marine microbial organisms on the one hand bacteria that are highly dependent on sulfur will proliferate such as purple and green sulfur bacteria and sulfate reducing bacteria on the other hand living organisms have difficulty synthesizing the ammonia they need because this synthesis is intimately linked to an enzyme containing iron of which the Canfield ocean has little their development is consequently slowed down a continental riff forms 1.6 billion years ago it extends along the western margin of laurentia Eastern India the southern margin of baltica the Northwestern margin of South Africa and the northern margin of the North China block strong magmatic activity accompanied this upheaval the total fragmentation of the continent was spread over 300 to 400 million years [Music] the great story of the cells continues 500 million years after the cells were equipped with organelles allowing the production of energy a new organelle essential in the functioning of the plant cells will make its appearance the chloroplast like mitochondria chloroplasts are the result of endosymbiosis and capture the light that causes photosynthesis [Music] It Is by feeding on external elements that cells with a nucleus ingests certain photosynthetic bacteria and that Arrangements intervene at the level of the symbiotic partners cyanobacteria are photosynthetic microorganisms that can capture light thanks to pigments and are able to synthesize their own organic matter Gene transfers take place between the nucleus cell and the ingested bacteria the resulting cell consists of the genetic material of its nucleus that of its mitochondria and that of the new elements it becomes a self-sufficient cell until then organisms reproduce by simple division from one generation to another they remain almost identical to themselves the biosphere will evolve considerably with the appearance of a new mode of reproduction sexual reproduction it is a great step in the evolution of the living this complex form of sexuality is called meiosis a normal cell containing two sets of chromosomes divides into specialized cells whose nuclei contain only one set of chromosomes each cell must then find a complementary partner to fuse and reconstitute a cell that will then have all the chromosomes fertilization consists of the fusion of the male and female sex cells and thus the reunion of two sets of chromosomes such a mixing of genes will generate an enormous diversity of individuals and the appearance of new species [Music] plate tectonics continues to turn the continents upside down 1.1 billion years ago under its influence the Continental mass is regrouped and formed rodinia the eastern coast to the current United States is close to the western coast of the current South America and our current Antarctica in Australia are adjacent to the west coast of the United States a planet that looked very different from what we see today the supercontinent rodinia is surrounded by the ocean mirovian it extends from 60 degrees north latitude to the South Pole inside its seam zones rodinia has a huge rust-colored plane on which Sands accumulate the surface of the Earth is completely deserted the life remains confined to the Aquatic environment since the atmosphere contains only five percent of the concentration of oxygen that we know today situation which does not allow the development of the layer of ozone which protects the surface of the Earth of the ultraviolet rays the surface temperature is estimated at an average of 10 degrees Celsius or almost 50 degrees Fahrenheit the sun is six percent weaker than today and its rays are not as powerful a day lasts at that time less than 22 hours and a year has 13 months the formation of a supercontinent like rodinia acts like a lid on the planet this cover evacuates the heat from the earth only by the phenomenon of conduction which is not very efficient the heat that is not evacuated accumulates and causes the temperature of the upper mantle and the lower crust to rise the central parts of the continent become hotter as a result the density of the Rocks decreases they rise to the surface and form huge domes the crust is stretched and becomes thinner cracks appear from which magmatic rocks and fusion pour out the volcanic activity intensifies a Superdome formed 850 million years ago cracks one million years later lava takes place in the trenches created as they move apart water invades the trenches and new oceans are formed new conditions were created that would allow life to find Refuge from the harsh events it would endure over the next few million years about 750 million years ago rodinia broke up at that time the supercontinent is centered on the equator subjected to the effect of hot spots the Earth's crust is crossed by enormous quantities of lava that pierce it like Spears oceans and inlets open up increasing the amount of water vapor in the atmosphere heavy rains fall on the earth and subject the fractured Continental rocks to a strong alteration this phenomenon consumes a lot of CO2 the size of the coastline grows marine and Coastal organisms proliferate using massive amounts of carbon dioxide from the atmosphere lava flows caused by the breakup of the supercontinent form basaltic surfaces on the surface of Continental blocks under the effect of humidity these basaltic surfaces erode and consume large quantities of CO2 deprived little by little of carbon dioxide the greenhouse effect is reduced the Earth appears calm the oceanic ripples are not very active but the average temperature at the surface of the planet decreases considerably to the point that freeze-ups occur the Earth becomes snowball again ground temper temperature averages between minus 40 degrees Celsius and minus 50 degrees Celsius I.E between minus 40 degrees Fahrenheit and minus 58 degrees Fahrenheit when night falls it drops to between minus 80 degrees Celsius and minus 100 degrees Celsius that is between minus 112 degrees Fahrenheit and minus 148 degrees Fahrenheit the sun is about six percent less powerful than today it shines less intensely and produces less energy its Luminosity is low a climate of desolation rains on the Earth the air is dry and cold unbreathable because of its low oxygen content no more liquid water circulates except at the base of the glaciers which puts the water cycle at risk the freeze-ups follow one another and get out of control in a real vicious circle the icy surfaces get bigger and reflect more and more sunlight into space this is the famous Albedo effect the temperature at the surface of the Earth decreases even more the thickness of the ocean ice reaches more than one kilometer like a large pearly mattress the ice nevertheless leaves gigantic crevices in some places in which organisms are resisting the fauna and undergoex and conditions but also find Refuge at the bottom of the oceans within a thin strip of ice-free water that has been able to survive thanks to the extraordinary properties of water as water cools its density increases and Below 4 degrees Celsius or 39 degrees Fahrenheit its volume also increases even after it freezes during the Ice Age the water begins to cool at the surface it becomes denser and a current is created the cold water flows and homogenizes the temperature over the entire depth as soon as the temperature drops below 4 degrees Celsius or 39 degrees Fahrenheit the surface water becomes less dense and remains at the surface this is how the ice form creates the thermal Shield that prevents the sea floor from freezing and allows organisms to survive the veranger glaciation would have benefited the diversification of life according to some research at the end of the glaciation when the ice melts the erosion of the continents leads to the release of large quantities of phosphorus this phosphorus is dissolved in the oceans and encourages the proliferation of phytoplankton oxygen is released into the atmosphere which facilitates the appearance of new organisms as in most ice ages the Earth's core remains active throughout the veranda glaciation emissions of CO2 Rich volcanic gases do not stop so after a million years the Earth's thick ice cover begins to melt greenhouse gases take their place in the atmosphere since nothing else transforms them there is no more alteration of rocks or biological consumption the ice melts and the surface of the Earth warms up at a crazy rate from minus 50 degrees Celsius or minus 58 degrees Fahrenheit to 50 degrees Celsius or more than 122 degrees Fahrenheit scientists assume that this sudden warming is due to a sudden and massive release of large quantities of gas accumulated under the ice the planet is freezing itself from the snowball that was imprisoning it during its fragmentation the supercontinent rodinia is separated into two parts an ocean was born between the two panthelasa North America moves southwards towards the South Pole the northern half of Virginia under the pressure of the ocean turned on itself making its eastern part go up to the north much more than its western part between these two parts a third Continental block extends the Congo Creighton a few million years later these three continents came together to form a new supercontinent called panotia which remained in place until 540 million years ago the Collision gives birth to a mountain chain the pan-african origin and welds the various African crepes this new continental block formed is of remarkable stability so much so that it will later give birth to Africa life is confined to water before 600 million years nothing protects it from the ultraviolet ray is emitted by the Sun the molecules of living matter are photosensitive and can be destroyed if they are confronted with certain radiations like ultraviolet rays ozone has three oxygen atoms this molecule is formed following several chemical Transformations involving nitrogen oxides under the effect of the sun's ultraviolet rays ozone then accumulates in the stratosphere for this phenomenon to occur oxygen must be sufficiently abundant in the atmosphere it is at this time that the ozone layer begins to form present at 90 percent of the current amount it will reach its totality 200 million years later ozone is naturally limited and balanced since it is constantly created and removed by the activity of ultraviolet light and oxygen it absorbs a large part of the ultraviolet rays and protects living organisms from their harmful effects with a formation of the ozone layer Marine diversity will explode the Earth has just suffered climatic catastrophes but the biosphere is hanging on as the ice melts the ocean reappears and life prepares to reclaim the Waters of this new Earth the deglaciations cause a strong Continental erosion and consequently an important sedimentation of the literal zones the sediments contain various organic matter emanating from the multiplication of organisms present in the coastal Waters this organic matter is transformed into carbon the sequestration of CO2 from the atmosphere by the sediment supplies oxygen to the oceans and then to the atmosphere the living beings have now extraordinary possibilities of diversification thus the famous Fauna of world extension named Fauna of erikara makes appear large strange animals still entirely deprived of rigid parts this fauna is found on all the continents which means that it is not a question of a regrouping of organisms in only one place subjected to very specific conditions this fauna developed on the whole surface of the Earth which represents a great step in the development of life edacarins are among the most intriguing fossil groups ever discovered they are unlike any other living creature with a soft body no mineralized skeleton they have a padded appearance they take various forms going from the round like the jellyfish to a radial tri-radial or bilateral symmetry to that of a disc with a head the edocaraphana nests on most continents which is quite rare for organisms living on and in the sea floor as the Earth is recovering from an Ice Age the oceans are still cold at this time and the climate zones have not yet recovered measure from a few centimeters to more than two meters in length for the largest they are the first Fauna of large organisms to have developed or at least to have fossilized some live under the Sands of the seafloor and can move and push themselves when sediment is dumped on them others develop tubes connected to their bodies to fill them with sand the Fauna of edakara has about 100 species and a dozen groups and many organizational plans the main groups include discoid forms mainly simple flattened discs they look like jellyfish but are really quite different since they live in dense populations on the seafloor the maso knights also have discoid forms they measure about 12 centimeters or 5 inches in diameter and their bodies have tubes or Pockets filled with sand the bodies of Vendo bions like rangia are bag shaped with bilateral symmetry they live buried in the sand one of the best known families of the edia karafana are the dickinsonids including dickinsonia they have the shape of a small flat oval disc and they evolve into a ribbon by widening and flattening a longitudinal axis divides the ribbon into two parts with thin segments on each side the dickinsonia can measure from a few millimeters to 1.40 meters or 5 feet in length they do not have a digestive system nor a mouth and anus they feed by consuming bacterial films that cover the sea floor yourgoids and vendibiodes also have segmented and discoid bodies with one indifferent from the other they are able to crawl on the sediments this sharnia group have fronds it is attached to the sedimentary surface and stands on the sea floor most of these organisms measure about 10 centimeters but some reach up to 2 meters if there are enough of them in close proximity to each other they form small thickets on the sea floor the trilobosarians are a remarkable group of ediacarans they have a body with tri-radial symmetry including three lobes Twisted in a spiral which remains rare in this population they are discoid and present surprising and unknown details that really differentiate them from other living forms they are mostly covered with branched radial grooves their diameter varies between 0 3 and 5 Centimeters that is to say almost two inches for the biggest specimens the edia karafana cannot be mentioned without referring to the microbial mats that cover many sedimentary surfaces they are at the base of the food chain for some Eddie occurrens While others simply filter microorganisms from the seawater the Fauna of Eddie acara flourished until 542 million years ago it represents a first diversification quickly aborted of the pluracellular animals the cause of its disappearance Still Remains mysterious today several hypotheses are proposed such as a general disturbance of the environment a biotic replacement following the appearance of new species of Cambrian type or a change of polarity of the Earth's magnetic field which would have reduced the ozone layer and thus increase the ultraviolet radiation on the surface of the Earth four large continents form the landscape of the earth following the breakup of rodinia they are located mainly in the southern hemisphere laurentia represents the ancient lands of North America and Greenland Siberia is located east of laurentia baltica composed of Scandinavia and Western Russia is located southeast of laurentia the last Continental block not the least which stretches from the South Pole beyond the equator is gondwana this last piece includes the ancient terrains of South America Africa Australia India and Antarctica the lapitus ocean flows through the middle of baltica and laurencia the emerged lands are still uninhabited and without life they undergo erosion the sea spreads over shallow depths and covers Continental shelves this creates ideal conditions for life to develop the metazoans are quite numerous even if they are not varied and have a microscopic size between one and five millimeters metazoans are the group of organisms that qualify animals they are multicellular since they contain several differentiated cells their cells have a nucleus and organelles such as mitochondria they feed organically in parallel with a tectonic events of this period life begins a profound Evolution and a decisive turning point in the evolution of life on Earth 541 million years ago it is the Cambrian faunal explosion some scientists call it the Big Bang of life it results in a gigantic renewal of the fauna new plans of animal organization appear a company by new Genera and new species nearly half of the current phyla are identified at the beginning of the explosion the Cambrian faunas composed of epigenthic animals which live on the sea floor they are partly burrowers and pelagic and have new ways of feeding the food chains are more complex than those of the edekarafana the reasons for this explosion are still debated today but an interesting hypothesis tends to be validated a rapid and important slip of the Earth in relation to its axis of rotation would have moved laurentia and parts of gondwana from high to low latitudes this event would have been followed by Marine transgressions the temperate coastlines of the continents and the increase in Shallow submerged Continental surfaces would have allowed life to proliferate and consequently would have led to an exceptional increase in diversity during this period which lasted until 485 million years ago three different faunas succeeded each other the tamat fauna the chingjiang fauna and the Burgess fauna the tomato is characterized by small and very Diversified fossils measuring between one and three millimeters long they belonged to sponges mollusks and other annelids they exhibit calcerius Celsius or phosphate shells this fauna represents a major phase in the diversification of multicellular animals with shells and in the mineralization of skeletons it is considered a key fauna even if it only lasted a few million years like the edia Cara fauna the tamashian fauna is recognized worldwide it includes some modern looking organisms but most are made of tiny blades needles caps tubes or domes called the small shell fauna by paleontologists it is mostly made up of the beginnings of shells small scattered fragments it is not confirmed today that these first fragments of shells would have represented the beginnings of an evolution of animals with shell or that they would have remained single organisms which disappeared very quickly the tomat fauna marks the appearance of a group of organisms belonging to the sponge phylum the archaeocayaths they are the first bioconstructors in association with calcifying microbial organisms to raise organic masses up to two meters or six feet in height and several meters or feet in diameter on the sea floor these masses are the pioneers of the complex Reef ecosystem that will develop a few million years later archaeocyeths consists of a calyx formed by two nested porous cones they're skeletal parts are made of magnesium calcite they are sessile benthic and filter feeders in order to ensure their feeding they are found in habitats subjected to a current and a strong turbidity ensuring them a supply of nutrients they do not have great capacities of adaption and have constraints of temperature salinity of the water and depth [Music] the Fauna of changing is represented by at least 16 different phyla and about 196 species with a strong predominance about 40 percent of arthropods vertebrate and invertebrate organisms are present in great variety these fossils were covered by a layer corresponding to the mud of a warm and shallow sea which allowed a remarkable preservation of the anatomy of their tissues whether hard or soft as well as the elements of their Digestive and nervous systems the groups recorded are extremely varied sponges algae canadarians annelids numerous bilaterians as well as at least four groups of vertebrates haikuathis is the first true vertebrate identified as such it could be classified as the first vertebrate fish but it does not have all the characteristics to be included in the fish group has a bony skull but no jaw it was more a prey than a predator it is a small animal not exceeding 2.5 centimeters or one inch in length it is very fast and agile thanks to its anatomical structure and can face many predators living in the ocean at that time like slimy worms or big arthropods it has a series of w-shaped muscles called myotomes that are attached to its bones located in the dorsal region this allows it to propel itself easily and have better control of its movements thanks to the myotomes and the supporting skeleton its head is differentiated from its body since its body structure is divided into two distinct zones its organs are also better protected the skeleton begins to play a protective role in addition to its supporting role it is made up of Bones and not cartilage has adapted and evolved with time its muscular structure became more able to control its movements thanks to a nervous development it perceives better the environment in which it evolves it has a dorsal nerve cord it develops gills the main respiratory organs of aquatic animals thanks to them haikuatus extracts oxygen from water and carbon dioxide and sends it back to its external environment the Fauna of chingjiang revealed strange and amazing forms such as animal locoris or opabinia is a huge Marine creature that belongs to the family of animal akaraday or strange shrimp this segmented invertebrate is a very original specimen it has two large eyes in the shape of rods swimming legs two appendages going up near the mouth like shrimps as well as a flattened mouth its mouth was first assimilated to a jellyfish and then describe as a kind of pineapple slice decorated with several layers of sharp teeth they are mouth elements crushing trilobites thanks to its flexible arms animalicarus catches its praise and can put them directly in its mouth its mouth small rigid and circular also enables him to Aspire small praise like worms active Predator it is a good swimmer even if it does not beat speed records it propels itself thanks to the undulations of its side lobes like the fins of certain fish obabinia does not belong to any known phylum until today it is the proof of a very complex and diversified invertebrate fauna it measures between 4.3 and 7 centimeters up to three inches its body is soft and segmented on its head we count five eyes [Music] it has a long and mobile proboscis like a trunk attribute exclusively seen on this animal which makes it an extraordinary creature this proboscis folds up its mouth and is equipped with prehensile spines being used to catch its praise it searches the sediments to find its food thanks to its lateral lobes it can survey the seabed and move around and thanks to its proboscis it recovers its food in the tunnels dug by worms or bivalves the Burgess fauna is dated to 505 million years ago compared to the two other faunas it constitutes a real explosion in the literal sense of the term since it sees the appearance of a quantity of new complex and varied organisms it is the Fauna of the Big Bang of life it was discovered in a sight in the Rocky Mountains in Canada it was found to be in continuity with a changing fauna and is in very good condition Burgess remained for a long time the only sight giving access to the Cambrian fauna the fossils were discovered in shales from a moral Limestone formation during sudden underwater Avalanches the organisms were buried under a mudflow their good state of preservation is explained by the fact that the mud carried with it all the small creatures on the seafloor it trapped them where there was neither oxygen to decompose them nor predators to devour them the extremely fine sediments insinuated themselves everywhere around and inside the organisms the small corpses were trapped whole under a sludge that gradually solidified into shale the Rocky Mountains were formed and the Earth's convulsions lifted and crumpled large parts of the Marine sediments some layers were crushed leaving no sign of life but one layer remained intact the places where the fossils of this fauna have been found suggest that these animals live on slopes of accumulated mud at the foot of a large imposing wall positioned almost vertically 120 Genera make up the Burgess Fauna of which 33 are ordinary organisms belonging to currently known phylum and which have an exoskeleton sponges brachiopods trilobites algae mollusks and echinoderms are among them 87 Genera of soft-bodied organisms are also listed this fauna is very original some organisms will not be found in the future geological times they will Mark only the Burgess fauna at that time there are 24 fundamental types of organization and arthropods and only four will persist arthropods have a segmented body with legs or appendages this division into segments appears from the embryonic life a rigid carapace constitutes their exoskeleton made in most cases of chitin thanks to malts they regularly change their external exoskeleton which allows them to gain in size to acquire new organs or even to change their shape arthropods are a worldwide group that can adapt to the different types of environment around them several species of arthropods evolve 500 million years ago rankyocaris is a kind of arthropod with a bivalve shell that hides two-thirds of its body it measures between eight and nine centimeters long and has a very segmented trunk at least 40 segments of annular shape this animal is provided with a pair of small antennas and a pair of clawed appendages it is an active swimmer and uses its appendages to bring food to its mouth Marella is a species of arthropod that is part of the soft-bodied fauna it has a cephalic shield and a body made of about 20 segments two pairs of uniram dependencies decorate its head its cephalic Shield has a horseshoe shape and is adorned with two kinds of horns curved extensions that run along the body for most of its length the rest of the body of Marella is thin this species is able to undulate its body in all directions trilobites are among the best known arthropods on average they measure between two and seven centimeters or about two inches but some individuals were up to 70 centimeters long that is more than 25 inches long they are present in abundance on the sea floor and are among the most Diversified there are nearly 19 000 species that have been detailed to date their specific Anatomy places trilobites in a very special group their trilobation is indeed unusual they have a median lobe and two lateral lobes which are protected by an exoskeleton the trilobites live only in water and more precisely on or in the substrate which constitutes the bottom of the sea some forms of trilobites evolve however in pelagic that is to say that they live and move in a body of water to this end their exoskeleton is modified so that the body has more stability and they also have a better View trilobites live in groups they feed on worms and any other benthic invertebrate sidneya measures between 5 and 13 centimeters in length about 5 inches its structure is singular its head has only a pair of eyes and a pair of antennas but they are the first creatures on our planet with Advanced eyes on their so-called compound eyes each facet has its crystalline lens of calcite oriented to perceive the maximum amount of light possible in only one eye fifteen thousand elements are contained the trilobites have a practically hemispherical field of vision the segments of their thorax carry a pair of solid appendices this carnivorous animal walks on the sea floor in search of food mainly small trilobites and hyoliths the trilobites will spread in the ocean and divide into a large number of species among the phylum of annelids one animal stands out for its unusual structure it is hallucinogenia with a long and slender body like that of a worm the animal has seven pairs of tentacles that end in claws on one side and join spines on the other it moves on its tentacles and its spines are erected on its back the three pairs of fine tentacles at the level of its head are used to sort out its food and to orient itself like antennas [Music] sponges also Adorn the Cambrian sea bed these animals are equipped with an aquiferous system that allows the circulation of water sponges are adorned with two layers of cells on the outside the pinnacoderm and on the inside the shoanoderm in the middle of the two layers mobile cells circulate in a cellular matrix mainly composed of collagen sponges adapt to fresh or Marine Waters they can settle up to 5000 meters deep they are great consumers of bacteria organic debris and algae they feed by filtering the water the water which is filled with particles enters through the pores of the sponge large particles are absorbed organic particles are digested and inorganic particles are rejected through the pores sponges are very strong even if they are crushed or torn off their cells reassemble and regenerate they are also resistant to changes in acidity and survive during climatic warming and ocean acidification [Music] [Applause] [Music] echinoderms are a very diverse group of marine animals that have the particularity of having a central Symmetry and a star shape called pentoradial they have a skeleton made of bony plates and have a water system like sponges to function the body of echinoderms uses hydrostatic principles their feet are like small extensions provided with suction cups maintained inflated by the pressure of water the water circuit necessary to the functioning of this system is independent the water enters through a hole drilled in a ring around the mouth and it spreads throughout the body through internal channels one of the most widespread species of echinoderms is the sea Lily in its flowering stem form the sea Lily has a three-part body a root system with spikes that allows it to attach to the sea floor a stem that can be up to 1.50 meters or five feet long with a base that is stiffer than the top and a calyx covering the vital organs topped by a dozen mobile feathery looking arms to feed the sea Lily spreads its arms and captures planktonic particles the sea Lily is spared by Predators because most of its body is calcified it is able to regenerate itself it lives in Shallow Waters attached to hard bottoms such as clusters of shells the last of the Burgess fauna that we will talk about are the brachiopods they are present in great numbers and in a very Diversified way their shell is composed of two valves a ventral valve and a dorsal valve inside there is a brachial skeleton from which filaments spring up that capture Plankton and Lead it to the mouth brachiopods live attached to their substrate there are 12 000 species of brachiopods at this time including lingualella buried in the sand and mud of estuaries this species looks like a long worm with two horny valves at one end its structure is complex its tentacles are covered with vibrating cilia that cause water currents the acilia are loaded with food particles which are then led to the mouth the tentacles have another important function they absorb oxygen and act as gills to allow the animal to breathe the valves protect the tissues and concentrate the water currents over the next hundred million years brachiopods improve their valves considerably all these elements of the ecosystem are in balance with each other future events will disrupt their peaceful life [Music] it is now 485 million years ago and life is about to emerge the area around a volcano after an eruption is among the most Barren of lands the black lava flows that previously rolled down the flanks are now Frozen steam flies between the blocks and yellow sulfur encrusting the mouths of the chimneys further away everything is quiet however the continents are not immobile they continue to drift and it by the convection currents of the Earth's mantle the Continental surface is empty like a great desert no bushes to protect from the wind nor Greenery to brighten up the black surface of the ashes although the evolution of the Earth has allowed the development of life in the ocean the dry land remains barren [Music] plants resembling lichens and our current mosses begin to settle on land these first colonizers reached the rocks and cling to all their irregularities they then developed spikes the water not yet circulating in their tissue they let themselves dry out until rains fall and they rehydrate completely other plants resist drying out by developing an impermeable cuticle that reduces water loss through openings that allow gas exchange for the moment these plants have no leaves they are lying or standing they colonize an abundance the aerial and mineral environment and provide microorganisms with a raw material that will lead to the formation of the first vegetable soils a wide variety of organisms can now try their hand at these new conditions this conquest of a new environment is only the beginning of a large colonization which will radically change the aspect of the Earth but our journey stops here for today are you curious to discover what the Earth looked like 480 million years ago see you in the next video [Music]

Channel: Wondody | The World of Odysseys

Views: 174,299

Keywords: wondodi, science, space, documentary, earth, space documentary, galaxy, universe, mars, moon, nasa, abyss, ocean, nature, alien, history, solar system, life, water, history of the earth, origin of life, animal documentary, history documentary, natural documentary, dinosaurs documentary, journey, history of the universe, earth documentary, pangea, pangea documentary, supercontinent, earth history, universe documentary, earth 4 billion years ago, earth 4.5 billion years ago, earth 3 billion years ago

Id: 9-_0LxrqzBU

Length: 72min 32sec (4352 seconds)

Published: Sun Mar 05 2023