on the 16th of September 2018 a radio telescope array in British Columbia picked up a strange chirp from the Stars it was very brief lasting Just 4 milliseconds and it was very quiet equivalent to a cell phone signal transmitted from the moon but it had traveled a lot lot further than the moon it had traveled 500 million light years for the next 4 days that radio chirp kept chirping before falling silent for a couple of weeks then it started up again following the same pattern over and over again and this detection in 2018 was by no means the first or the only one fast radio bursts as they have come to be known were first discovered by chance back in 2007 originating from Far outside our Galactic plane they typically last less than a second but they are astoundingly powerful researchers have triangulated their sources to be many millions or billions of light years away so to make it as far as the Earth at all they must release as much energy in that sharp burst as the sun does in a year what's more scientists now think that they are a common feature of the universe if we had telescopes watching the whole Sky we would detect one every 10 seconds even so the chirp that was detected in 2018 was special among all the fast radio bursts ever intercepted it is one of only two that repeat on a regular schedule with its repeating 4-day long period of activity followed by 12 days of Silence it is unique and researchers hope that it will help to shed light on the causes of fast radio bursts and solve one of the biggest outstanding Mysteries of the universe because for all their power and abundance we still don't know what's Behind These intense radio pings it is tempting therefore to daydream that in a l L spiral galaxy not unlike the Milky Way The Source could be intelligent an advanced species whose Mastery of the universe was vastly greater than our own and whose technology allowed them to harness and release energy in quantities that we could only dream of but of course even in the unlikely event that this was the case whatever the source it would be long gone now for the fixed speed of light means that these fast radio bursts began their Journey 500 million years ago and even if the journey had somehow been instant there wouldn't have been anything to recognize those radio waves when they arrived for 500 million years ago on Earth there was no technology there was no civilization no sentient life indeed from space the planet would have looked scarcely any different to how it had for the 4 billion years years since its birth blue oceans white clouds bare Rocky continents indeed at first glance there might be no life visible at all but despite its radio silence and its calm passive exterior the planet is a Roar with activity and [Music] Innovation after a fairly steady 4 billion years Earth has entered a new era a new geological period and a brand new new Rhythm things move fast now since animal life exploded onto the scene the planet has already been through boom and bust flip-flopping from Tropical Paradise to suffocating hell and back again this new Paleozoic world may not be a technological Marvel able to receive signals from millions of light years away but it is a geological and biological one it is far different from any time on Earth before and it sets the stage for all times to come the Earth took roughly 10 to 20 million years to form equating from gas and dust whirling around the Sun that made sense for the Earth but it probably isn't the best time frame or method to build your website ODU is our sponsor today and and they are a fantastic all-in-one business operation software that offers a range of applications and the first app is free for life I went with their timesaving website builder which is totally free and Incredibly simple to use it just takes a few clicks and works using a drag and drop system within minutes you can have a fantastic fully functioning website with chat GPT integration that can write reword and even change the tone of your text and a great royalty-free image collection you're also able to easily modify each block by clicking on the element you want to change having a website is hugely important these days to boost your presence online and ODU offers a free custom domain for one year with unlimited support and hosting as you do so it's a Top Choice so follow the link in the description below or in the attached comment to try it out and you will have a fantastic website in minutes thanks to Odo for supporting educational content on YouTube the wind howls around the control room of the troll Research Center sending the anomer just outside whirling into invisibility its sound almost drowns out the crackle from the radio as the room's sole occupant gives her daily weather update wind 35 knots trending Northerly temperature abami - 7° c visibility 5 km it's another beautiful summer day in the Norwegian quarter of Antarctica if you don't mind a little wind Norway's only year round research station sits somewhat isolated 235 km away from the Antarctic Coast but its location was not chosen at random this collection of prefabricated buildings is perched on the bare exposed rock of util cess a bizarrely shaped Mountain Ridge that stands proudly above the endless ice sea that surrounds it the station's name itself is thought to derive from the supposed resemblance of these rocks to trolls the Mischief Makers of Norwegian myth being positioned on the Rock gives the resident researchers a rare opportunity to study the solid basement that underlies Antarctica's flowing ice on the surface dark brown granates weather to spectacular Jagged Peaks like the ones that Tower above the squat research station while Cliffs of gray tortured metamorphic rocks are Crosscut by black and white intrusions of ous rock and mineral veins only by closely studying the tiny materials inside this complex tangle of ancient rocks have researchers been able to decode its history and determine that yut cess as well as the rest of the 100 kilom long Orin range is a remnant of the last great mountain building event in the Assembly of the supercontinent gondwana some 530 million years ago and it was the American paleontologist Charles ditt Walcott who first uncovered the fossil puzzle that would reveal the true shape of the Cambrian Earth in 1888 exploring the east of New Foundland Walcott had already made a name for himself as a fossil hunter extraordinaire and this expedition was no exception he found woodlouse likee trilobites in great number and curious diversity from Tiny blind agnostics to huge spiny paradoxides or of which had once thrived on the shallow ocean floor but there was a problem with the assemblage of fossils he documented despite being separated by just a few hundred kilometers they were completely different from the species found in the shallow seafloor rocks of the same age in Western Newfoundland and it would take another 50 years and the rise of the theory of plate tectonics before scientists would arrive at the correct explanation through petrological paleomagnetic and fossil evidence geologists were able to reconstruct an ancient vanished ocean more than 3,000 km wide named the iapetus in roughly the same location as the northern Atlantic [Music] today things changed fast and drastically after the snowball glaciations that marked the end of the neopro around 630 million years ago during that freezing time for the planet lasted ing almost 100 million years many of the Earth's Continental masses were assembled over the South Pole they may have been clustered or they may have been combined into a vast supercontinent named pinosa but the end of the Neo protozoic saw the end of pinosa new ocean basins ripped through the once Consolidated mass of continents casting out lorentia which now forms much of modern North America and Bala whose remnants today form northern Europe between the Rena and Bala a mid ocean ridge sundered and began to spread opening up a huge ocean Basin much like the modern Atlantic this was the iapetus and yet for all its vastness the only evidence of its existence today is in a narrow band of crumpled rocks and the Curious puzzle of Cambrian fossils Walcott found in 1888 running through England Scotland Ireland and New Foundland for just 10 million years or so later Lorena and baltia would begin moving together again to close their Aus ocean but in the late Cambrian at least the North American and European continents enjoyed their independence however the same could not be said for the rest of the planet's ancient continents as the remnant mountain range in Antarctica upon which the troll research station sits a tests the breakup of penosha did not see a wholesale scattering of Continental masses indeed even while lorentia and Bala were Breaking Free the modern day southern continents were still strengthening their Association South America and Africa were nled together as their puzzle piece geometry suggests Madagascar was squeezed tight between Eastern Africa and India with Antarctica press in close beneath it finally Australia shouldered into the Continental scrum slotting in between Eastern India and Antarctica together this vast assemblage of Continental masses as the earliest Inc aration of the gondan and supercontinent covered around a fifth of the Earth's surface it lay almost exclusively in the southern hemisphere hovering close to but not directly over the South Pole the weathered surface of rock beneath the troll research station was therefore once the heart of a mighty mountain range and peering out of the control room window at the shattered rocks Beyond this lone scientist could easily imagine herself perched on the slopes of the Cambrian kunga mountains in their Prime in Central [Music] gondwana there are no birds here no insects no plants blowing in the wind only a few colored lyans eek out in existence on the tumbled Boulders of the Talis slopes there's little moisture in the air and few clouds to sh Shield the rocks from the Relentless sun such is how we might find the interior of Cambrian gondwana on the wrong side of the kung's rain shadow in many ways Antarctica's Orvin mountains form a tiny modern window onto conditions on the Cambrian continent but there is one big difference and that is temperature while troll today Shivers in a cold desert the mountains of the kunga range rise from an altogether different desert among the hottest that the world has ever seen while its long coastline enjoyed a maritime climate with moist variable weather and moderate temperatures the endless Continental interior of gondwana was subject to the harsh climatic extreme that such large land masses breed humidity from the oceans can only be transported so far and the mountain ranges born from Continental assembly act to further block the penetration of clouds and rainfall thousands upon thousands of square kilometers lay dry Barren and empty their Solid Rock surfaces only weathered by the shattering heat and abrasive wind it was an inhospitable place even if there were any lifeforms on Earth yet able to call it home delving into the genetics of modern plants it's possible to estimate when they made their first four Rays onto land based on how common the genes for sub Arial survival are cross referenced with the time it takes for such genes to evolve these so-called molecular clocks do seem to suggest that plants had acquired some of the genetic toolkit for surviving out of the water by 500 million years ago and yet if there were any such Hardy terrestrial Pioneers there is as yet no evidence of them in the fossil record that in itself is not so surprising early plants fact the hard Woody vascular structures that are most likely to leave a trace in the Rocks while comparatively dry terrestrial environments don't easily produce the conditions needed for making a fossil gigantic gondwana was drier and much more hostile than most land masses making it even harder for Continental colonizers to gain a root hold or leave their Mark if the interminable desert of central gondwana wasn't hostile Enough by itself throughout the lake Cambrian the supercontinent Eastern Realms were subjected to their own unique flavor of hell today more than 2 million square kilm of the Australian subcontinent spanning Western Australia the Northern Territory Queensland and South Australia are underlain by volcanic rocks dating from a single event that took place a little over 500 million years ago they are known as the karingi flood Basils and they are the result of an immense outpouring of lava from a volcanic eruption that took place on a scale never yet witnessed by Humanity this was not an explosive eruption like Mount St Helen's but a relatively gentle yet persistent flow of runny lava from one or many Rifts in the solid crust perhaps the closest analog today are the flows of basaltic lava that continually reshaped the landscape in Iceland but the largest of these flows to take place in human history the elku eruption of the 10th Century covered about 780 Square km with basaltic lava the karingi flows were more than 2 a half thousand times greater from fishes in the ground many kilometers long lava first sprayed and then serenely poured as if from a NeverEnding Reservoir the deadly golden Rivers flowed inexorably down hill carving channels in the barely cooled landscape and spreading out into soft edged loes at the end of their runs until the fishes and vents were finally exhausted and a brand new basaltic plane three times the size of Texas had been [Music] created it was not just molten rock that diffused from these fissures along with the lava came gases great billowing plumes of water vapor that filled the otherwise clear gondwanan skies with steamy clouds and invisible but no less pernicious carbon dioxide in staggering quantities scientists estimate that more than 1 and A2 trillion tons of the gas was emitted in the decades long Basel flood this eruption alone contributed an extra 2% of carbon dioxide to the Cambrian air no doubt affecting what was a remarkable time for the global atmosphere and climate it's still difficult to know with any great certainty what climatic conditions were like 5 100 million years ago but clues in the chemistry and formation of the rocks from the time point to conditions very different from those of the preceding Neo protozoic or today carbon dioxide may have reached staggering concentrations some 16 times higher than even current levels and its warming effect as a greenhouse gas would have contributed to average global temperatures of up to 22° C compared to the modern average of 15° as we stand on the cusp of catastro ropic global warming it's not hard to imagine how inescapably sweltering the Cambrian world would have been the interior of gondwana suffering from the privations of continentality could have baked at temperatures hot enough to break apart organic molecules essentially sterilizing the continent from even bacterial life the coasts the cooling ocean could have given some relief but the humidity and ensuing storms would have made this Refuge a turbulent one and of all the Rocks laid down at this time no evidence has been found that suggests that ice existed at the poles this was made possible partly because none of the late Cambrian continents lay directly over the pole to act as a geologically and thermodynamically stable platform for an ice cap but either way Ice's absence is scarcely surprising in such a hot Greenhouse environment condition at the surface may have been unbearable but the main consequence of such high temperatures and the lack of ice around the globe is that all of the water on the planet is now free to cycle between the atmosphere rivers and oceans today some 2% of Earth's water is locked away Frozen as glaciers and ice sheets and we are all acutely aware of the devastating sea level rises that even just a small melting of that ice will bring about but with it all gone as in the late Cambrian those sea level rises would have been as Extreme as at any time in Earth's history topping out at up to 90 m above present day levels of course at this time there were no coastal cities civilizations or even habitats to be drowned by the encroaching ocean but there were plenty of communities that stood to benefit just as the karingi lavas flooded out over the ancient Australian landscape the Cambrian ocean Waters flooded over the fringes of all the ancient continents the result was a vast expanse of shallow tropical ocean shelves around the edges of all the land masses shallow enough for the sun to penetrate to the sea floor across much of their area and to readily exchange oxygen with the atmosphere they were also close to the rocky land masses to feed off nutrients from terrestrial weathering sheltered just below the waterers surface F A hair's breath from the steamy stormy hellscape above these were aquatic Edens where life forms could want for nothing the perfect environment for life to [Music] experiment Adam Cedric pulled the oil skin close to around him and spared a glance at the glowering gray clouds that loomed above him pricking his ears for the sound of thunder the last thing he wanted was to be caught out by a storm while he was so exposed on this bare Welsh Mountain Side it would hardly do for the morning papers to report that the Cambridge professor and president of the Geological Society had been struck dead by lightning he threw his second glance in the direction of his young field assistant 30 ft away and saw that the enthusiastic but inexperienced Charles Darwin had no care for their meteorological Peril he had his nose pressed so close to the boulder at the lake shore as to make the rest of Kum idwal and indeed his mentor all but disappear it was [Music] 1831 the English geologist and mapping Pioneer William Smith had demonstrated some 30 years prior that the relationships between rocks that cropping Cliffs Road cuttings and beneath our feet can give their relative age to one another layers that laid on top of others were younger having been deposited after those that languished beneath so far so simple but the real Mastery was in untangling the present day pattern of folded faulted and regionally discontinuous rock formations to piece together a complete and consistent geological history and the key to doing that Willam Smith had asserted was fossils so now cedrick and his acolyte as well as many other English gentleman geologists with the means and motivation were taking it upon themselves to map the rocks of England Wales and Scotland in a Time long before any understanding of plague tectonics or Evolution or indeed any agreement on the age of the Earth these Scholars were carving out the major geological ages Darwin wasn't Cedric's usual field companion instead Cedric was more often seen with his friend and colleague the drastically more capable field geologist rodri merchon it may come as a surprise therefore that these two Cedric and merchon were the root of one of the biggest controversies in 19th century geology in a fight that would see the pair estranged from one another until the end of their lives and at the heart of This Bitter dispute the honor of naming the rocks that contained the very first fossils of life on Earth it began in the early 1830s with both geologists working independently to log and map the rocks of whales Merson focused on the borders and mid whales where he used fossils of trilobites and clam likee brachiopods to define the syuan GE iCal system meanwhile Cedric's fieldwork took him to North Wales and exposures like those he explored at Kidwell with a young Charles Darwin there were fewer fossils here so instead the professor used other characteristics of the rocks to chart the changing geological formations and Define his own geological system named after the Latin word for Wales the Cambrian all seemed well with the pair's independent conclusions but their camaraderie was not to last somewhere in between the two Scholars field sites the rocks of Cedric's Cambrian seem to overlap with those of mches and syuan rocks that we know today are around 500 million years old so to whom did they belong merchon said that the fossils in these overlapping rocks were not different enough from his syuan ones to be considered distinct and so claimed the top part of Cedric's sections for his own for that matter he reasoned none of the so-called Cambrian fossils showed any standout characteristic that separated them from those of the syuan so merchison wasted little time in sweeping all of Cedric's rock formations into his own system of course today the Cambrian Period is still within the geological dictionary and still defines the period with the earliest unquestionable fossils so we can rest easy that cedrick got his Justice in the end but that Justice did didn't come until 1879 6 years after Cedric's death although the scholars Welsh sections had been pouring fossils further exploration around the country and further a field led to the discovery of more truly distinctive Cambrian fossils providing justification for his original conclusions and running from 538 to 485 million years ago and merchison got to keep his syuan period as well well running from 443 to 419 million years ago the resolution to the contentious overlap was the definition of a third geological system which became known as the aivis sandwiched in between and so in time the true Riches of the Cambrian Period would reveal themselves the discovery of remarkably preserved soft body fossils in the burges shade of Canada in Chang Jang in China and many other places besides have opened a window on the spectacular explosion of life that is now defined as beginning with the beginning of the Cambrian Cedric never knew how valuable the price of his period was and he would never know that his claim was Secure animal life as we know it arrived onto the scene over a few short tens of millions of years starting around 500 39 million years ago in an event fittingly described as the Cambrian explosion the reasons why it happened so suddenly and at that particular point in time have been scrutinized by paleontologists for over a 100 years with no clear answer as of yet but what is known is that recognizable macroscopic life and almost all of the animal fer the major groupings that Define cordat like us mollusks like oysters and octopuses and every kind of worm in imaginable appeared within a geological blink of the eye apparently without following the bizarre example of the soft quilted bodies of the edar and biota at the end of the Neo protozoic the early Cambrian organisms Diversified explosively learning how to build hard protective shells to swim freely in the water and burrow down into the sea floor all the while exploiting new food sources all of this diversity still only existed in the oceans but with a warm climate no ice and elevated sea levels there was plenty of ocean to go around by 500 million years ago the lake Cambrian marine environment would have been a breathtaking scene at first familiar with its reefs and sunlet Waters filled by colorful life forms bustling about their lives with a skittish air of self- protection but a closer look would reveal the scene to be un nerving the alien while the animal forms that colonize the Cambrian ocean do belong to the modern filer they are what's known as basil forms the first experiments into living with a particular body plan before the pressures of environment and competition have caused them to evolve refining and branching into the denisons of their group that are preserved in the furoic fossil record and which survive to today and so the reefs that rise up up off the sandy sea floor reaching for the sunlight are not made of the branching spreading or gently waving tentacled corals that the modern snork would expect but rather there were jumbled assemblage from oddly delicate cone-shaped structures known as aroids these organisms have not survived past the Cambrian and have no clear existing descendants but paleontologists believe them to be allied with the sponges belonging to to the philm periphera like the sponges that exist today they lived as filter feeders channeling water through pors in their skeleton to extract the tiny Plankton that floated helplessly within with their double walled conle calide skeletons reaching up to half a meter in height and stacked on top of one another in a bid to reach the nutrient Rich Waters of the ftic Zone these Cambrian aroid reefs look more like a well stocked ice cream paror than any Reef we would find today likewise representatives of the new animal filer may not appear quite as we expect in these Cambrian Seas the cordat defined by the nerve that runs like a cord along their bodies today comprise all animals with a backbone these number some of the largest and most charismatic of the ocean's denisons from the great blue whale to the great white shark and every fish and Aquatic mammal in between but in the Cambrian Seas Cates were just getting started they had no bones but strengthened their bodies with cartilage they also had no limbs but they had segmented blocks of muscles to help them squirm wri and undulate through the water and across the sea floor the basil cordat like picaya Yuan once called hella miloon menia and metasena would have looked and moved similarly to Modern eels and Lam but in miniature most of these early Cates topped out are just 5 cm long the film that is most closely related to the Cates to us is surprisingly the Ain ofms their modern Representatives can be found intitled Rock pools and shallow tropical oceans as spiked sea urchins heart-shaped sand dollars and multifarious starfish but all of these are derivations the product of hundreds of millions of years of refining evolution the earlier KY ofms that could be found lurking in the Cambrian Seas looked barely anything like their modern cousins their inclosing outer shells were constructed from Individual calcified plates but therein the similarities end instead of an ordered five-part symmetry these early urchins experimented with a more free form kind of body plan some like the eocrinoids were cup-shaped anchored to the Sea Flor like a goblet with plated arms reaching upward into the water column others like the tenyo looked a little like limbless silverfish with flattened oval bodies bearing a movable comb like apparatus at their front end whether for eating or for movement we are still not sure finally the helicop ploids have the appearance of a towel rung out to dry if that towel happened to be made of rigid armor with a distinctive spiral pattern to their interlocking plates as well as to their mouths as well this elongated rugby ball-shaped creature could stretch and squash its body to generate water currents around itself to feed without ever moving from one [Music] place the forer of these Cambrian Waters was unlike anything the Earth had seen before or would see again with barely any modern analoges measuring animal diversity in the aftermath of the Cambrian explosion is far from straightforward certainly the animal life was alien from that of modern day oceans but how does it rate in terms of overall diversity and abundance it is a question that has puzzled paleoecologists since Cedric and mergerson first sparred over the earliest animal fossils nearly 200 years ago to begin with merely counting the number of species is unreliable since we are limited by the imperfect fossil record and what our equally imperfect interpretations can tell us the general consensus is that the richness of animal life increased explosively at the beginning of the Cambrian and kept increasing even by some measures doubling during the Paleozoic so in 2007 a group of American paleontologists forged a new approach to measuring ecological richness which depends Less on what Marine fossil organisms look like and more on how they lived called an ecospace it can be visualized as a large C cube made of 216 smaller cubes numbering six on each side each position along each of the sides represents a particular way of living along the Cub's length are feeding strategies from suspension feeding to grazing to preparation along its width there are degrees of motility from staying attached to a surface to moving fast or slow and along the Cube's vertical axis is tearing or where in the marine environment they made their home from deep in the sediment to on the surface or up in the water itself so a free swimming predatory shark would occupy one small square and a rooted suspension feeding Coral would occupy another in the opposite side of ecospace by categorizing fossil organisms into this ecospace paleoecologists can see at a glance how many of the possible ways of living are being exploited by ancient community unties and changes in ecospace filling over time can tell the story of Extinction and radiation arguably better than any individual count of fossil species by this measure the ecospace count during the preceding edaran period when only enigmatic quilted organisms lurked near the ocean's surface was just 10 out of a possible 216 clustering around the non-moving surface suspension and deposit feeders but contrast the Cambrian ocean had tripled its ecospace filling most notably through the exploitation of new habitats beneath and above the ocean's surface the camaran explosion had not only seen the rapid appearance of new and bizarre forms of life but the invention of completely new ways of living there were now free swimming Predators burrowing worms floating suspension feeders and an abundance of fast moving bottom feed us and yet this is still but a small proportion of all the possible ways of living with less than 14% of the total ecospace filled so while the Cambrian ecological Innovation was remarkable inventing both the major animal body parts and many new ecological modes Evolution still had far to go to create a marine ecosystem like the one we see today indeed Evolution still has room to maneuver since our modern oceans still only fill less than 100 out of the possible 216 incremental ecosystems even now there are no Predators who make a living attached to floating debris or fast moving Bottom Feeders living in Shallow sediment and many others besides and so this Cambrian forer as shown by the Limited ecospace filling is composed primarily of suspension feeders and sediment grazers that lived right at or near the sediment interface it is defined by many of the simple but numerous Shelly fossils that can be found in Cambrian and aivis rocks all over the world but over and above all else there are trilobites like the New Foundland examples that include Charles doitt Walcott into the great missing iapetus ocean indeed just as the Jurassic and Cretaceous might be described as the age of dinosaurs the Cambria and UD divis with the age of the [Music] tribit in 1862 the British Geer JW sulter was attempting to map the rocks that outcropped around the coast of St David's peninsula in Southwest Wales he decided that the best way to do this to gain access to the sheer Cliffs that drop per perilously into the sea was by boat but while sulter may have been a skilled geologist he was not quite so Adept at Marine navigation at the end of his mapping day he turned his skiff into an inlet he believed to be solva Harbor but was in fact a dead end the narrow Bay of pory he was lucky many Navigators who have made the same mistake in coastlines around the world have found themselves run a ground but sulter came across a calm and sheltered Bay where he could Mo his boat and never being want to miss an opportunity he examined the Rocks before him and it was in these rocks he found the treasure of a lifetime it was a tribit that much was obvious from its helmet-like Cranium and numerous stacked thoracic segments but it was on a scale he could scarcely believe because While most trilobites then known to science were on the order of a few centimeters long this extraordinary example was almost half a meter in length it has since been named paradoxides davidi and is now celebrated as wales's National fossil the trites don't have to be large in order to be impressive these woodlouse likee animals are so named because of the three-lobed appearance of their dorsal shells which are further subdivided into head thorax and tail sections but therein the similarities between members of the group ends because so far more than 20,000 species of traby have been identified across 11 separate orders they ranged in size from just a few millimet to up to 70 cm in length and had adopted every possible lifestyle that was practical for an animal of their particular design there were blind scavengers that lived inside the sediment in dark crevices or below the photic zone though were masters of Defense long thoraxes made from thick articulated segments allowing them to roll into a protective ball there were elaborately spiny species whose sharp perturbances may have been a deterrent to Predators or may have been a way of sensing disturbances in the water and then there were troby eyes compound eyes made from tens of thousands of individual crystals of calite like gemstones specifically oriented and arranged to give remarkable depth and Clarity of vision in the varied and dark Waters of the Cambrian ocean the arrangement of these lenses show astounding diversity suited to each individual species lifestyle most are curved to give a wide field of vision for spotting Predators or prey approaching from the front side or behind some are raised on stalks to allow the trilobit to borrow down beneath the sediment to lay an ambush of unsuspecting prey and some have huge bulging dome-shaped eyes that dominate the size of their heads and allow 360° Vision in all directions when swimming freely through the water truly the trites were the Triumph of the Cambrian forer the masters of all they beheld and so it is clear to see from the individual foral the Paleo ecology and the Cosmopolitan trilobit dominated community of these tropical seas that 500 million years ago life was enjoying meteoric success but the story of life in these oceans hadn't always been one of unfettered Victory because amongst all this experimentation Innovation and diversification there was also crisis and hardship for 500 million years ago the animal communities that had poured their evolutionary energies into this newfound Eden had already faced an Extinction event one that saw almost half of them struck prematurely from the [Music] earth tourists flock to the arm sh shaped peninsula of Cape cord in Massachusetts for the ultimate nature lovers vacation hundreds of kilometers of Sandy Coastline offer endless opportunities for water sports Wildlife watching and dining out on Sumptuous Seafood sheltered bays and ponds are the perfect place for paddle boards and kayaks while the low green rolling landscape is ideal for relaxing walks among the unspoiled beauty of nature the region has made a name for itself as one of the happiest places to live in America and it's a top destination for retirees but the 200,000 or so permanent residents are thoroughly outnumbered by more than 4 million annual visitors but all of it is under threat and in the next few years the beauty and Bounty of the cape could be lost altogether for visitors in the next few years will be greeted by a pervasive rotting odor among the bays and ponds there will be no local fish on the restaurant menus and boat propellers and ORS will be so clogged with debris as to make whale watching and water sports the thing of the past and this isn't some Far Future worst case scenario even in 2022 conservators estimated that 90% of the cape's coastal Waters would need immediate restoration and it's all because of an excess of nitrogen in the water and this cape cord is not unique uncontrollable choking algal blooms are becoming a common site around the world especially in estries where the chemical products of intensive farming make their way into the sea but farming isn't the reason why Cape cord's aquatic habitats are suffocating rather the popular destination has become a victim of its own success with the nitrogen pollution coming from too much urine entering the ocean out of the 15 small towns on the cape most of them have no sewers reling instead on septic tanks that only catch solids while letting the waste water flow into the ground and then the sea completely untreated when that waste water includes the nitrogen Rich urine from millions of tourists it's little wonder that Cape cod's waters are struggling and it's a problem that's only projected to get worse as the number of annual visitors is expected to grow like the apocalyptic red tides that beset the coast of Florida this yellow tide threatens the habitats e ecosystems and overall environment of the cape all because something in this case nitrogen sent the system teetering off balance these kinds of tipping points and their catastrophic consequences are becoming a common feature of our modern changing world but the Earth has experienced many such crisis in its long history and it is now becoming apparent that the Cambrian oceans experienced one such crisis around 500 million years ago the fossil record reveals that for a few tens of million years after the Cambrian explosion animal life experienced the ultimate boom time with both extrinsic environmental conditions and intrinsic evolutionary potential working in Step resulting in unprecedented diversification and radiation through the planet's shallow tropical oceans but any Economist as well as the residents of C cord will be the first to tell you that you can have too much of a good thing the overreaching and overe exploitation of resources during a boom sends the system off balance and invariably leads to a bust the wildly successful Cambrian ecosystems would have been a delight to behold but they were a system tipping dangerously off balance now that an abundance of fossils of both hard and soft-bodied animals have been recovered from the entire C Cambrian Period it is possible for paleontologists to chart the rise of animals in precise detail but those records reveal something surprising the extended Cambrian radiation was not a tale of uninterrupted success and that rise in ecosystem richness was not a continuous one about 5133 million years ago and 9 million years ago there were instead sharp drops in species abundance and diversity together they comprise a pair of mid-cambrian extinctions that have been named the sysk event and the pomian tonian crisis between these two sharp Jags amid the otherwise upward trend of Cambrian success paleontologists see an alarming loss of up to 45% of all newly forged animal Genera particularly focused upon those with hard mineralized skeletons among which around 83% of gener disappear the aroids those ice cream cone Reef Builders of the early Cambrian are among the most notable of losses leaving their heaped and hopeful skeletons behind as ghostly reminders of their ultimately unfulfilled potential and many species of traby met their demise as well including groups that were among the very first trilobites of all which had been especially dominant on the opposite shores of the iapetus ocean and included the famed Welsh Giant paradoxides indeed many of the organisms that have been so iconic in the Cambrian oceans never made it out of those Seas it's clear from the chronology alone that with boom and bust in such quick succession the mid Cambrian was not a stable time for the Earth but the cause of these Extinction events is not immediately obvious there are no asteroid strikes no Global glaciations even the Australian flood Basils and their massive outgassing of greenhouse gases took place after the ecosystem change so the two could not be related there is one clue however lurking in the rocks of the period that could help geologists to piece together the events of the mid Cambrian known as the stepan positive isotope carbon Excursion or more simply spice it relates to a marked change in the balance of carbon Isotopes inside the Limestone which in turn tells us about conditions in the ancient ocean there are two stable isotopes of carbon carbon 12 is the most abundant carbon 13 is endowed with an extra Neutron in its nucleus making it marginally heavier it accounts for just over 1% of Earth's carbon Reservoir and in recent decades geochemists have used High Precision Mass spectroscopy to measure the quantities of each of these Isotopes in carbon bearing rocks such as limestone this is because the balance of carbon 12 to carbon 13 in the atmosphere is heavily controlled by biological productivity ultimately life is lazy and won't expend more energy than it needs to so photosynthesizing organisms will preferentially take up lighter carbon 12 from the atmosphere leaving behind the heavier more energetically costly carbon 13 and so many of the big extinctions on Earth are marked by negative carbon 13 excursions reflecting Mass dying all over the world and yet the space event records the opposite a positive carbon 13 Excursion Around 500 million years ago lasting 2 to 4 million years implies enhanced primary productivity at this time more photosynthesizers fixing lightweight carbon and draining it from the atmosphere usually it would follow that more production at the base of a food chain means more food for the consumers who rely on it but this is not necessarily the story that these carbon Isotopes tell because although the lightweight carbon is captured it's not cycled up through animals and back into the air but is locked away the photosynthesizers algae and cyanobacteria are living and dying in such numbers that their organic material is buried before it can be used and so could this this be a clue to the mid Cambrian animal extinctions was it a lack of food that somehow drove these early Shelly forer to their demise it seems unlikely unfortunately the exact dates of the spice event don't quite line up with those of the extinctions coming several million years after the big drops in animal Genera if anything the positive Excursion that the spice event records is a consequence of the extinction rather than its cause there is however one more tantalizing clue in eastern Nevada around 320 km north of Las Vegas shingle Peak Rises nearly 3,000 m above sea level and is composed of fossiliferous limestones that date back to this crucial period in Cambrian history here scientists have traced the spice event in the carbon Isotopes but they have also found crystals of fool's gold iron pyite decorating the rock layers like beads on a necklace pyite is an ion sulfide which forms in sedimentary rocks where there is abundant sulfur and not very much oxygen or else the sulfur would react to become a sulfate pyite in this context is widely considered to be an indication of anoxic water conditions something that is confirmed by examination of the sulfur Isotopes within those crystals and it's not just shingle Peak that wears this evidence of anoxia like gy jewelry all around the world rocks from the mid Cambria concurrent with the foral extinctions show the Hallmark signs of a drop in oxygen concentrations this probably didn't come from a drop in atmospheric oxygen but rather a deoxygenation of the ocean oan floor the same ocean floor that played host to diverse animal [Music] ecosystems with this final piece of the puzzle the mid Cambrian Extinction is starting to make sense the Cambrian explosion saw ecosystem Evolution supercharged for a few tens of millions of years some speculate that it was precipitated by a rise in atmospheric oxygen or Continental configurations pumping abundant nutrients into the shallow tropical waters either way it was a time of unprecedented biological success not just for the newly evolved animals but also for The Aquatic photosynthetic algae and bacteria that fed those animals in the first place but all this growth sent the ecosystem tipping and then tumbling out of balance algae could grow wherever there was sunlight in nutrition and with the warm temperatures and weathering of a newly fractured continent there was no shortage of either if the founding animals couldn't keep up with such abundant vegetative growth then that growth would continue exponentially unchecked this meant that much of the Cambrian Seas could have experienced the same fate that the urine soaped shores of Cape Cod now face algae grow out of control before dying and decomposing drawing all of the oxygen out of the water from the sea floor upwards and it's likely that warm global temperatures and a lack of ice at the poles contributed to Ocean circulation stalling leaving many of these deoxygenated sea floors suffocating and stagnating for Millennia the animals that called them home didn't stand a chance ultimately the fornal crisis that interrupted the cambrian's housian days of summer probably came about as a result of life living just a little too hard thankfully this period was relatively shortlived and whether through some intrinsic feedback or a change in nutrient flow to the oceans conditions improved by the end of the Cambrian to allow the ecosystem to regain some balance and recover the mid Cambrian extinctions may have been noteworthy for the proportion of animal General lost but looked at another way the absolute magnitude of these Mass dyeings was not actually that great there was a much lower density of form among the metzo and fer than at any other time in the furoic there were perhaps only a total of 600 distinct gener at the peak of the Cambrian radiation which was reduced to around 450 by the end of the period compared to the 73,000 500 gener known to exist today both the total diversity and losses sustained are so small as to be almost unremarkable and yet even so though those surviving Genera were remarkable the animal groups that appeared in the aftermath of the Cambrian explosion and which had the temerity tenacity or simple Good Fortune to survive through life's meteoric rise and catastrophic fall were the ones that would shape the founding branches of the tree of animal life these early extinctions almost acted as a filter culling the delicate vulnerable forms and favoring the more resilient we may mourn the loss of some of the cambrian's most experimental organisms but the ones that survived would be our Founders defining the course of evolution for the next 500 million years a course of evolution that would eventually lead to [Music] us you've been watching the entire history of the earth don't forget to like And subscribe and leave us a comment to tell us what you think 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