Miracle Planet : Snowball Earth

our planet was born in violence and grew with disaster four billion years ago primitive life may have been drifting in the oceans but disaster the seas were lost to intense heat yet science tells us life survived deep underground it waited for the oceans to return life's goal is to survive no matter what and survive it in first through fire and then through ice on a miracle today in New York is a thriving cosmopolitan City one of the great cities on earth yet 20 thousand years ago this whole area was covered by last sheets of ice glaciers browned their way through Central Park large rocks that have no right to be here it's as if they were dropped erratic by some mythical giant before geology was a science it was recognized that they were from another place some thought they were the debris carried by the waters of Noah's Flood they were carried by water but not liquid water ice to the north Greenland is still a country of ice large rocks locked in glaciers are slowly transported away from where they were originally formed gracious move very slowly there forward motion can be measured in years rather than in distance but when the ice melts the cargo it carries is dropped geologists call these rocks erratic or drop stones for science they are important pieces of evidence they give clues to the evolution of life Erick's are found across the globe and they are proof as to which parts of the earth were once covered by us 20,000 years ago some parts of the world are locked in ice in Canada near Lake Huron there is evidence of a far earlier Ice Age when the entire globe may have been frozen Mike Hale stone a district geologist with Canada's Ministry of Northern Development and mines knows where to find rocks that predate the last ice age by billions of years this is the one that I wanted to show you it's an arc Ian's granite boulder stuck in a rock that's 2.4 billion years old it's a dynamic tight formed from a glacial action that occurred 2.4 billion years ago throughout the region there are rocks and gravel sediments that really have no place in local geology they are all between 2.2 and 2.4 billion years old older rocks are found in younger strata as if the earth has constantly recycled its crust the rocks have been moved by a continental drift as well as by glaciers to try and locate where they originally came from takes us back into the past glacial sediments over two billion years old have been found in at least seven different parts of the globe until fairly recently trying to pinpoint where they came from has been purely educated guess word Namibia in southern Africa is an ancient landscape carved by wind and erosion but glacial sediments also show that ice once played a major role now hot and dusty as well as isolated it is a hard country to work in for geologists though it can be a paradise dr. Joseph Kahn shrink is from the California Institute of Technology his specialty is magnetics the earth is surrounded by magnetism produced by its own magnetic field the way compasses work long ago as they formed on the Earth's surface but jagged rocks in this riverbed history were molten lava these are lavas that erupted about 2.2 billion years ago during one of the largest snowball earth glaciations it's kind of neat it interrupted underwater in seawater and as the magma cooled the magnetic minerals in the rock were able to record the direction of the magnetic field at the time the lavas here actually are about a thousand meters thick total and by looking at the magnetic directions in this pile of rock we're able to calculate very precisely what the latitude was the time they erupted and the amazing thing is that there's only 11 degrees it's kind of like the latitude of Costa Rica now and that means that the entire planet must have been under ice because if it's cold on the equator has to be colder towards the poles molten lava contains many minerals which are magnetized as the lava flows these minerals follow the magnetic force of the earth once it cools the magnetic direction of that moment is fixed forever it is then possible to locate exactly where the rock was formed to do this one matches the magnetic history of the rock with the angle the lines of geomagnetic force that surround the planet once that has been determined the latitude can be fixed in a tightly shielded room the faint magnetic records held in the rock samples are detected at the center of the screen is the pole the further away a point is from the center the closer it is to the equator when the samples from Namibia were analyzed their magnetic compasses pointed to the fact that they all had originated near the equatorial regions closer to the equator than Hawaii and Guam on today this confirms that over two billion years ago there were traces near the equator to have glaciers there at that latitude implies that it has to be colder as you go north hence the entire earth right down to the equator had to have been frozen not once but twice for glacial sediments in strata dated between 800 to 600 million years ago from this data dr. Kirsch Fink put forward the proposal of the earth had been completely covered in ice at least twice in its history it was called the snowball earth and like many scientific theories this one is hotly debated children always enjoy scrambling around looking for hawks scene I remember I told you've got to hold it close to your eyes everybody gonna go right down on the rock and there are few better teachers than dr. Paul Hoffman of Harvard University for years now his passion has been geology and he is also a keen advocate for snowball earth the impact of the snowball events would of course be much more severe because organisms might try to escape towards the tropics but eventually in the oceans the ice will completely envelop the tropics because this ice is flowing it will move into the tropics and meet at the equator working with scientists of the University of Tokyo a computer simulation was carried out to show what would happen to today's world if a snowball earth event were to occur as the world begins to cool frigid winds would reach much further into the tropical regions arable land would start to freeze today there is life across the globe this was not the case in the two previous snowball events at 35 degrees north Tokyo is just a little further south than New York ice up to 1,000 meters or 3,000 feet thick would bury the city at first any life that could not find shelter would freeze to death at the start the glaciers would move slowly or take millions of years for the ice to reach a latitude where Hawaii and Cuba are but from there to the equator would take only a few decades Paul Hoffman thinks that the sea might freeze down to a depth of over half a mile some life might escape under the eyes but only for a while for sunlight would be cut off and the base of the food chain would die it was seemed as if the world would become a dead planet but life is present on the earth today so where could it have taken refuge and an even more extensive and we think very interesting place where life would have survived would be in cracks that would always develop because the sea ice is flowing whereas the ice that is at the coast would be frozen and locked in place and therefore there will always be a shear between the glaciers flowing in the ocean and the land fast ice and so cracks will continually open and then freeze and an open and freeze and open and freeze and there's a very rich biota that lives in cracks and in channels of salty water that get enclosed within new sea ice how a snowball event gets started is still not fully understood but strangely it may have something to do with the gases which keep the earth warm without these gases the average temperature would drop well below freezing moderate levels of carbon dioxide helped to keep the planet warm but there is evidence which suggests and prior to the first snowball event these levels were far lower if so what kept the planet a large area of wetlands and swamp in the southeast of the United States and give some clues to the makeup of Earth's early atmosphere the Okefenokee National Wildlife Refuge covers an area of 400,000 acres the shallow warm water is sometimes only knee-deep beneath the surface the swamp floor is soft and spongy Dom Berry here was a science teacher now as a volunteer guide he enjoys sharing both his love for the area as well as his love for science see where I'm digging down here look what's coming out all right that's what gas is produced by the bacteria and the fungi down there as soon as the bottom of the swamp is disturbed gas bubbles escape it is a highly flammable gas called methane this gas is sometimes used in households for cooking but here it is produced by microbial life they're called methanogens unlike so much life on the planet today methanogens don't rely on sunlight for energy instead they get their energy by breaking down nutrients and making methane as a waste gas scientists believe that methane was the greenhouse gas which kept the early Earth warm as methane bubbles to the surface we now know that climate change is nothing new and is a specialty for dr. Jim casting of Pennsylvania State University who is a leading researcher in atmospherics his research shows that if there was no carbon dioxide in the atmosphere methane alone could keep the climate well above the freezing level but if you go back prior to the rise of oxygen around 2.3 billion years ago then methane levels could have been much higher there might have been a thousand parts per million of methane and that by itself would be enough to counteract they reduce luminosity he believes that the atmosphere then would have appeared reddish because of the high methane levels at that time in the planets existence there was no life on land no plants no animals the only life forms were microbial and lived in the oceans matheno jeans belong to a group of microbes known as the archaea a different branch of the tree from which the microbes were eventually to evolve to higher life they belong to the family you Korea and they are the ancestors of life today then a totally new organism emerged into the oceans perhaps a single-cell mutated when reproducing it something we'll never know but these cyanobacteria were to change the world they were the first organisms to convert sunlight into energy and as a by-product produce oxygen a process known as photosynthesis oxygen was released into the atmosphere in huge quantities and in those days there was nothing that could use it doctor casting thinks that had reached a level when its reaction to methane accelerated eventually eliminating methane from the atmosphere over time the world would change from its reddish color to blue with nothing to stop it oxygen production continued unabated for millions of years far story about the rise of oxygen is correct and this is anti gaya life destabilize the climate these little microorganisms you know cause the rise of oxygen cause the decline of methane and triggered a global glaciation which you know may have come close to wiping them out but you know the Earth's system fortunately is very resilient and it manages to recover from global glaciations in a way that we think we understand then the Sun was smaller than it is today so with the one blanket of methane removed the world began to cool there were no other greenhouse gases to want it so slowly the planet began to freeze nice had kept the planet warm and now life was bringing chaos and disaster what we have learned is that when there is a mass extinction in the aftermath those organisms that are quick off the mark and can take advantage of empty eco space and seize those places even if they are not the most advanced or most suitable organisms if they can get there first and establish their foothold they can be very difficult to dislodge and so after each mass extinction there's a new biota which takes hold and becomes ascendant for a long period of time perhaps until the nest next mass extinction scientists believe that if there were snowball events then they must have persisted for millions of years during that time the face of the planet would have seemed a frozen and desolate wasteland as parts of Iceland are today there was perhaps a chance that life could survive in water beyond the oceans living from the heat and energy that comes from the earth itself Iceland is known for its volcanic and thermal activity the land has only a thin crust above the heated mantle of the planet it's it's very close to awesome power and force Hot Springs are found across the island where the heat of the earth forces its way out places like these could have been a safe haven for microorganisms which like the heat the thermophiles dr. Viggo Mortenson and his team work for a company which hopes to use rare microbes for research so very steaming coming up from death gong and it's places like this where thermophiles can live where the water bubbles out it's too hot for just about any living organism but cooler edges are full of bacterial life look this is great this is all covered with cyanobacteria it is rich all kinds of species the life in these pools is made up mainly of bacteria which photosynthesize the microbes cluster together to form thick mats the earliest evidence of organisms like this appear before the first snowball event even then the green filaments of cyanobacteria would have clustered together around them are other microbes able to tolerate high temperatures of living off the nutrients perhaps this was also where our distant ancestors found shelter from the ice the geothermal area is a refuge for life life like this where you can find cyanobacteria or you can also find all different kinds of broad range of diversity of different kinds of bacteria maybe the planet needed a disaster like a snowball earth to let new forms of life take strides forward shortly after the ice melted life had changed greatly even if it was still Manute this is a microorganism known as choanoflagellate it's an unusual group of microbes which cluster together in colonies these are the closest known ancestors of animals and us and for the next billion years life Stood Still there were no further advances if we were to compare the Earth's history to a single year then microscopic creatures were life's main force up until mid-november but the second snowball event about 600 million years ago was to change that forever life's history is painted in its rocks this barren wasteland was once the bed of an ancient ocean Namibia in southern Africa is mostly a harsh and arid land but this means that the rocks that lie upon the surface are relatively undisturbed by water erosion were moved by flooding ketched into some of the scattered rocks of strange shapes and forms as well as here on a Namibian farm similar fossils have been found in Siberia Australia and you feel increasingly on the other side you see the positive crops of the same fossil fossil certainly but fossils of what to us as lay laymen we we didn't know what it was it could be anything from official or phone actually it looked more like a fish but then later on even the scientists weren't sure whether it was a plant or whether it was a living organism these fossils date back to the end of the second snowball event and they were neither fish nor leaf they were the first living creatures larger than microbes to appear on the planet these were giant steps forward in evolution this one was named Tara Dean Ian and scientists think that it may have lived on the seafloor half buried in the mud they have a body shape and form which resembles nothing living in the modern age so too with this strange creature found in Siberia unnamed Georgia a stone with five strange fossil marks is a record of this animals movements on the seafloor this is the first time in the history of the planet that a living creature moved with direction and purpose this one too comes from Siberia and has been named Kimber Ella it had a snail shaped body and a strange long protrusion which allowed it to feed from the sea floor the first time that any creature had dug in the mud releasing nutrients back into the water this period after the second snowball earth is called the IDI Akram after a range of hills in South Australia where similar fossils were found and somewhere among these creatures was the ancestor for modern life it might have been this a fossil discovered in Australia in 2003 some think here is evidence of a backbone perhaps making this creature the size of an adult small finger the predecessor of the vertebrates we can only speculate as to how it lived after 3 billion years of life it was amongst the first creatures which would be visible to the naked eye both snowball events seem to have been crucial for evolution ii could not have happened without the first which saw the rise of organisms like this eukaryote although still tiny it was the thousand times larger than the early my pubes the mystery yet to be solved was how the ice melted once a planet like the earth was frozen it would reflect sunlight back into space and so remained frozen what did happen to melt the ice a hint can be found in this mine in the Kalahari region of South Africa this is the largest deposit of manganese to be found anywhere in the world all the oil was laid down on the bottom of an ocean floor just when the first snowball event ended dr. Joseph Kirsch ping from Caltech who first published the snowball earth hypothesis wondered if this deposit was in some way connected to the melting of the ice all the manganese in this mine were of manganese dioxide which can only form with oxygen the oxygen molecules bond with the manganese to form manganese dioxide this can be easily seen in a simple experiment first a solution with dissolved manganese was prepared bubbles of oxygen are fed into the solution and it begins to turn brown then black oxygen and manganese then bonded to become manganese dioxide which falls to the bottom of the tank this is what is thought to have happened during the first snowball event only molecular oxygen free molecular oxygen like we have in the air is able to oxidize the manganese and make it fall out as this black rust and what we're standing on today and what you can see here is the evidence of a massive amount of oxygen being put into the environment just at this time just after the snowball he believes that the oxygen in the atmosphere of the early Earth was almost non-existent after the first snowball event it increased to around 1% after the second event it rose to 20% close to the level in the atmosphere today oxygen molecules also produce an enormous amount of energy and because energy became available life was able to evolve into larger and more complex forms yet the questions kept coming when we were faced with this data I had to sit back and say okay what fundamental things could be wrong if the earth did freeze it would clear it was clear that the equilibrium ice in the oceans would be one to three kilometers thick the entire surface of the planet would be white frozen like food to have obvious problems surviving maybe would not go extinct but it occurred to me that a frozen surface would not influence the working of geology but in particular plate tectonics and volcanic activity would not stop and it just hit me one morning that oh of course the carbon dioxide from volcanoes would continue to build up in the air volcanic gases contain large amounts of carbon dioxide which normally dissolves into the seawater but since the world was covered by ice the carbon dioxide had nowhere to go but up it continued to build to levels which may have been 2000 times higher than those of today as the earth warmed the ice began to melt you go from an average temperature of going down to minus 50 almost to plus 50 and at that point uh you melt the ice extremely rapidly it was the Earth's own forces which brought the snowballs to an abrupt and dramatic finish one study has suggested that when the surface of the sea reaches 45 degrees Celsius about a hundred and ten Fahrenheit it would trigger weather patterns that the world has never seen before or since the temperature differentials would cause massive hurricanes to build these hyper hurricanes would generate waves the height of buildings all this activity boosts oxygen production normally in nutrients which went into the oceans from the earth would settle back to the bottom will be consumed by bacterial life in deepwater microbes aren't harmed by a surging ocean from the hyper hurricanes many are transported from the depths to shallow waters but to imagine a hyper hurricane where you have waves maybe a hundred meters in height all of Florida would be wiped out I mean the waves would crash over and remove Florida I mean we have never seen something like this so it's difficult to imagine then when the winds died in the ocean calmed the Sun would heat to the shadows sunlight and nutrients photosynthetic microbes would explode in numbers releasing yet more oxygen the algal bloom would be so great that the Seas would turn green more and yet more oxygen would be pumped into the environment the strength of life which had survived to snowball earth periods had changed the planet and was about to embark on a new chapter but this time with abundant oxygen oxygen was the molecule that would change the world if earth had never experienced these glaciations life could have been quite different life here on earth might still be limited to the bacterial grade we could still be just a planet of slimy oceans and stromatolites with nothing big enough to move and do things at oxygen allowed one more innovation without which larger animals could not exist that was collagen the scaffold which cells used to bind together in this experiment in Japan synthetic collagen is mixed with cells in a culture these cells with collagen on the left of the screen multiply vigorously while those on the right are static cells begin to cluster together as they must in every large living creature vitamin C was added to create an environment in which it would be easier for cells to secrete collagen a thin tissue like skin has formed in the dish collagen is a unique material which is produced by all animals including humans it helps cells to shape tissue when a cell multiplies it assembles collagen that it has secreted into a fine net-like structure as the cells divide and multiply over and over the collagen allows them to create different shapes and tissues dr. Kenneth Tao of the Smithsonian Institute believes that it is collagen which gave shape to life after the second snowball earth and since collagen is made from many atoms of oxygen it could never have been produced if atmospheric oxygen had not been present after the first snowball event it's thought that collagen might have been available when oxygen became part of the atmosphere but then most of it was used for respiration after the second event oxygen rose dramatically because collagen is formed with two amino acids - do not appear in the genetic code it seems to me that that there was no way that evolution could find to make something similar to collagen without these amino acids and therefore it probably took a long time for this to happen and it's that is part of the problem the other part of the problem is that molecular oxygen is needed to make these amino acids that are important to make the collagen fibers that are important to allow bodies to increase in size for muscles to develop and be held together for skin for cuticles on all of these things so many things could have happened differently trillions of cells which make a human body are bound together by collagen and without collagen and without oxygen we would not be here today after the first snowball event there was little change in life after the second oxygen levels soared and the first complex life appeared expanding horizons and leading to higher and yet more complex life these strange creatures which evolved from the snowball events would not last long just a few tens of millions of years before a new life force took over now life could never step backwards and it was in shallow seas around a vanished alternate where the next step would be taken the fossil evidence shows a rich environment of corals and fish and other marine creatures corals need warmth than sunlight and there would have been an abundance of both at this time in the Earth's history we think that our closest ancestor was this fish called Aaron dispise it's the oldest-known fish with a backbone without fins it would not have been a good swimmer they would have been filter feeders sucking up microbes from the coral on the seafloor as yet no animal had developed a jaw so probably the deep waters were not a suitable niche for them to live but that would change there was a rich variety of life am i stirred were numerous trilobites small segmented and hard shelled creatures some were free swimmers while others crawled along the seafloor when the change came these creatures left clues which were picked up by an English paleontologist this quarry in Shropshire in the West of England was once near the equator and a part of the I app to see an ancient sea which vanished some 400 million years ago marine fossils and trilobites in particular are dr. richard forties driving passion Oh lovely look at this one it's a chain coral the abundance of fossils in the coral record suddenly vanished a sure sign that something drastic happened to this environment there were other noticeable changes to life as well China bites began to alter their appearance some began to grow protective armor it's almost certain that they were response defensive response to being under greater pressure from a variety of predators life in other words have got a little bit tougher for the trilobite and one of their responses was to increase their protective armor life undertook a new development in body shape suddenly in the fossil record we find fish like this sleek fast predators the world began to be divided into predator and it was the start of the arms race on the miracle planet you

Channel: EvolutionsSolutions

Views: 285,561

Rating: 4.6489606 out of 5

Keywords: Miracle, Planet, 2of5, Snowball, Earth, DivX6, AC3, www, mvgroup, org

Id: 87hHbiWBwmY

Length: 49min 56sec (2996 seconds)

Published: Fri Sep 23 2011

Reddit Comments

[u/rebelbasestarfleet]

So glad you posted this. I saw this series when I was younger and I still love the whole aesthetic of it. Haven't thought of it in years!