Chapter 3 The Young Earth
It may surprise you to learn that scientists do not agree on what life is. Some change their minds from time to time; others don't worry about the question believing the answer is known in some other science. In ancient Greece, when philosophers believed that all neuter was alive, a physicist was someone who studied nature --- physics --- and so was concerned with living things. Later, when scientists decided to divide the world into animate and inanimate matter, physicists took on the job of describing how inanimate matter is put together, and biologists, whose name comes from bios --- way of life --- took on the job of describing living things.
Physicists think biologist know what life is because it is their job to know, but biologists keep changing their definition of life and they pass the question to how to tell life from non-life on to chemists, whose name comes from ancient roots having to do with the transformation of matter from one kind to another. So chemists divide chemistry up, in their turn, into two kinds: organic chemistry, the study of living matter, and inorganic chemistry, the study of nonliving matter. Chemists know something about the transformation of inorganic matter into organic matter, but the question of just when and where life began on our planet still gets tossed back and forth among them, or taken back to ideas from physics. Some scientist talk about life in terms of non-equilibrium thermodynamics. This contrasts it with the equilibrium dynamics of nonliving things --- the physicists' way of solving the problem they created long ago when they declared that life was separate from non-life.
Before religion and science parted company, the answer to the question of how life began was easily. Scientists themselves believed that God created living things, and putting them into nonliving world he had created for them. But later, when scientists tried to explain the world without bringing God into the picture, they were stuck with believing that life is a special kind of matter that somehow comes from lifeless matter. One version of this belief was know as spontaneous generation --- the belief thorns, for example, sprang from bits of dead garbage or rotting meat.
Louse Pasteur put an end to that, we are all taught in school. Or did he? His very careful experiments showed that worms come only from eggs, and never directly from garbage. But where did eggs, which are living things come from? The explanation seemed easy with a theory of evolution: they came from other worms, which ahas evolved from the smaller, simpler creatures we traced all the way back to microbes --- living things so small they can be seen only through microscopes.
But where do microbes come from? That is still difficult to tell, but we assume they come from the simplest molecular systems that could maintain and reproduce themselves. Some biologists believe that life began with small clumps or sacs of organic molecules. The organic molecules themselves are considered nonliving matter that comes alive when they get struck together in certain ways that permit them to act on each other to form a living system. In other words, scientists still believe that life comes from lifeless matter. In this sense, spontaneous generation was not so much disproved as pushed down to things much smaller than dead meat and worms.
We are still stuck with the question of what life is. What is it that brings the lifeless molecules in some places on some plants, to life when they are chained and clumped together in certain ways? Event hough we are talking about ver tiny things, there is still a big jump from nonliving matter to life.
We have already suggested that it might be better to see life as a process than as a kind of matter. Perhaps it would also help if scientists did not keep looking for the answer only in tinier and tinier parts of nature, believing that in doing so they would see just how things are built from the bottom up.
If we begin, instead, by thinking of wholes, or holons, that form their own parts from the top down, so to speak, everything looks very different. If we could watch a movie of the evolution of a protogalaxy sped up so that billions of years happened in a few minutes, what would we see? We would see it whirl and throb, grow and change, its parts dissolving and exploding, more complicated new parts forming in their place and even reproducing themselves as the mature galaxy took on its complicated form. Galaxies themselves spit apart and merge with others on collision. And within galaxies --- perhaps within all of them --- some plants produce what we all agree to be life.
While astronomers may speak of the lives of stars, they do not seriously count galaxies as living beings. Yet galaxies do some of the things by which we all recognize living beings in our everyday experience of Earth, such as keeping their form through many changes within them, creating and replacing their own parts, sometimes even growing and/or giving to form offspring galaxies.
The most promising definition of life among biologists, in fact, seems very nearly to fit galaxies. This is the definition of life we owe to the Chilean biologists Humberto Maturana and Francisco Varela. Their concept of life is a process called autopoiesis which in Greek means self-creation or self-production.
An autopoietic unity, or holon, produces the very parts of which it is made and keeps them in working order by constant renewal. An autopoietic holon works by its won rules and creates a boundary that distinguishes it from its environment and through which it exchanges materials with its environment
A holon = something that is simultaneously a whole and a part.
We do not see such boundaries around galaxies, yet galaxies are visible as distinct entities that maintain their shape while producing and reproducing their parts. The Earth also produces and renews its parts, including the thick atmospheric boundary through which it exchanges radiation energy with its environment.
Until now we have assumed that the entire universe is nonliving matter execpt for some matter on plants. But why should we divide the universe up in this way" Physicists now tell us that the matter-energy of the earliest universe was already, by its very nature, bound to form living systems.
This is, in fact, becoming an increasingly acceptable hypothesis among physicists who have revived the ancient greek concept of the source potential, or plenum, as a zero-point energy field (ZPF) --- the infinite energies existing at every point in space-time and from which source all matter is created.
We do not know whether planets such as Mars and Venus began coming to life and then failed to evolve because they could not keep themselves alive. It is ever clearer because they could not keep themselves alive.
It is ever clear that , as with the seeds and eggs of plants and animals, far more planets are produced than actually come to life. Planets must have just the right composition and be in just the right relationship to their star to come as alive as our Earth.
The majority of planets that do not come alive in their own right --- may still play a supporting role in the life of their galaxies.
The creatures we are used to thinking as alive, such as plants and animals, contain much supporting 'nonliving' matter in their woody trunks and shells and bones, their thorns and hooves and nails, hair and scales.
Nonliving planets may also be very much a part of live galaxies, perhaps even playing important structural roles in their dynamic.
What about Earth? It is not easy for scientists to jump from seeing the Earth such as a nonliving plant that became a one for living creatures, to seeing it as a single living being. The scientific studies of Earth have been divided to studies of living and nonliving matter.
Geologists have had the task of explaining how the geological 'mechanisms' of nonliving matter, such as rock, change with time and weathering. Their work was not intended to be mixed up with that of the biologists who study living things, since these living things have been and still are believed by most scientists to arise in ready-made geological environments and either adapt to them or die out.
Now, however, the jobs of geologists and biologists are getting mixed up whether they like it or not, for the same stardust that was transformed into a rocky planet continues to be transformed into living creatures.
What we are made of was stardust long ago, transforming itself into rocky Earth crust and, after a long transformative history of evolution, into us.
Almost all rocks on the Earth's surface are made of atoms that were once part of creatures.
We begin to see that there is more than one way to understand life. We just saw it as a mixture of geology and biology. Lets now try looking at it as a mixture of physics and chemistry.
Remember the forces, such as gravitation, that helped create patterns in particles and atoms? One of those forces is the electric force that hold atoms together. This deeps the outer particle of atoms, their electrons, from flying off into space away from their nucleus of heavier particles.
Powerful electrical or magnetic, fields were set up by the interaction of the Sun'g energy and the molten metal of Earth's core. We might compare this with a giant battery whose energy can be used to do all sorts of work.
At the microcosmic level, the electric force allows electrons to dance in two atoms, thus holding the atoms together as a molecule. The more atoms that dance together in this way, the larger the molecules formed.
The strong energy of Sunlight coming to the Earth's crust through the thin early atmosphere stirred up the molecular electric force within the great electric files, creating storms above and breaking up molecules in rock dust, mud, and seawater near deep ocean rifts below, re-forming them into new and larger molecules.
Such chemical reactions also happen elsewhere in our galaxy. The larger organic molecules such as those of sugars, acids, and lipids that were formed on the young Earth are also formed in large quantities and great variety somewhere in the center of our galaxy and perhaps all over it.
Some of them come to earth by way of meteors. It is even possible that meteors may fertilize those planet 'eggs' which come to life.
Some chemical transformations were due to electrical storms created among loads of cooled steam in the early atmosphere as the Sun's energy heated Earth's surface.
Besides helping large molecules to form, these storms drove a water recycling system, collapsing clouds into rain.
Rainwater ran over rocks creating grooves that over the eons formed riverbeds and valleys, carrying ground sand and dust full of rock salts to the seas. Rives and streams thus formed as the blood stream of our embryo planet, carrying the supplies needed to develop or evolve its life.
For a live planet needs not only a great deal of energy but also flowing matter such as atmospheric gases and water to move things about.
The planetary life is not something that happens here and there on a planet --- it happens to the planet as a whole.
Large molecules, sic as naturally forming sugars and acids, absorbed a lot of electrical energy, which was then useful in speeding up their chemical reactions to form ever larger molecules.
Earth life may be described as autopoietic --- self-creating --- holons forming within the great Earth holon.
In all its creatures, from its earliest microbes to later organisms, we find carbon, or rather reduced carbon compounds, which are carbon atoms which are carbon atoms surrounded by hydrogen atoms, playing essential roles.
The lively energized carbon of the Earth combined easily with oxygen, nitrogen, sulfur, and phosphorus to form all sorts of organic molecules and substances. In fact, you are made of very little other than these six elements in their rich variety of combination.
Among the giant molecules formed from smaller ones were proteins --- long strings of amino acids, which are themselves molecules made of various combinations of a dozen or fewer carbon, nitrogen, hydrogen, and oxygen atoms. Other giant molecules, assembling from both acids and sugars, were those we call ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). DNA may actually have been a later development of early living systems based on RNA. Whatever the exact sequence, DNA and RNA came to work together with proteins as they copying and building system of life. Protein with DNA and/or RNA formed molecular cooperatives that became the basic reproduction system of carbon-based life. Less than 5% of DNA is composed of the genes, which are blue prints for the specific proteins of which living creatures are composed. The role of the remaining more than 95% is still largely a mystery. We still do not know how to read the architectural blueprint.
Some scientists, however, argue that such partnership really could not have gotten under way until the molecules were enclosed in sacs, or membranes, that held them together with other supply molecules and protected them from being dissolved. The most likely candidates for such sacs are called liposomes, literally meaning fat bodies.
Liposomes, so tiny they can be seen only with an electron microscope, form as hollow spheres of lipid molecules, something like microscopic soap bubbles,whenever lipid molecules find themselves in water. This is because the tailsof these lipid molecules are hydrophobic, swinging quickly away from water,
Protein became the main material of which living creatures built themselves. While RNA and DNA stored the plans and made it possible for living things to multiply.
Some protein molecules came to play a particularly important role by speeding up what other molecules did --- say, by speeding up the chemical reactions that build new protein or copy DNA. We call these special proteins enzymes, and their wonderful talent for speeding up the chemical dance is very important to our planet's life.
In fact, the presence of enzymes has been suggested as one way of defining the presence of life, and the first enzymes likely occurred as a widespread chemical Earth event, perhaps both outside and inside early cells.
While details are still missing, this is essentially how the solid and molten crust of the Earth began to rearrange itself into living creatures. Some of its material gassed off into atmosphere, part reformed into seas, some broke up and was washed into the seas. With the help of great amounts of energy, larger molecules formed and joined into partnerships, set up chemical cycles in early liposomes, speeded up their won reactions with enzyme activity, reproduced themselves, and through all this established themselves as living, or autopoietic , holons ---the earliest creatures in their own right.
These creatures dwelt within the larger living holon that had given them life and to which they gave a new kind of life in turn.
Thus on the one hand we can say that tiny separate living holons evolved all over the Earth.
But on the other hand we can say that the earth holon was coming ever more alive as it evolved its own autopoiesis through a new kind of self-packaging chemical activity.
A holon = something that is simultaneously a whole and a part.
In our new way of seeing life as autopoietic systems that may be as large as the Earth or even larger, we can think of Earthlife as a planetary process --- as the chemical reactions of the planet's crust speeding up, transforming the crustal matter into a blanket of mass of microbes, which in turn transform more of the crust into their livable home.
This is the self-creating dance of a living planet driven by its Sun and by its own energy.
One way of looking at all this is to see the Earth as having come alive through all sorts of "border activity". The crust that stirred to life was the boundary enclosing the Earth and at the same time connecting it to outside energy from the Sun and to new materials coming in as meteors.
Then the first cells seem to have formed specifically at the boundaries separating and connecting the land and the sea, or separating and connecting the inner magma with the crustal surface at volcanic sea floor vents.
These cell's own boundaries made their individual lives possible by separating them from and connecting them to their environment.
At all levels from great to small, this border activity can be seen as highly creative and cooperative --- a lesson we humans, with the boundaries we have created among ourselves, might well take to heart.
Let's imagine that we are watching fast-running movie of the early Earth as it evolves within the larger being of our Milky Way galaxy.
As we approach the Earth, we see it whirling and heaving, its thin crust rising and falling, breaking and slipping, bleeding lava.
Meteors and planetoids, which are part of the supernova's debris, strike and wound the Earth, making great splashes of molten rock and gas. The thin atmosphere is often reddish with smog produced by the reactions of its won gases.
Lightning flashes, and seas form during heavy rains until masses of land and sea become distinct, though the seas are brownish beneath the murky atmosphere.
Slowly the crust thickens and cracks into plates that slide slowly over the surface, carrying the land masses into new patterns.
Patches of colored microbes appear and grow along the shores; gradually a tougher but clearer atmospheric skin develops, making the seas turn a sparkling blue. Much of the land becomes covered in green.
Now and then ice moves down over the green before withdrawing again to the poles, raising and lowering the level of the seas, covering and uncovering the land .
Everything is in constant motion. The whole planet is breathing in some gargantuan rhythm.
These changes actually happened over billions of years, at a rate too slow for us to recognize as very active.
Yet a billion years to your planet is less than a decade is to us. If we see these changes within the time span of a short film, our planet looks very mush like a living creature.
Already at this early stage the Earth begins to fit the autopoietic definition of life as it is creating its own parts, including the tiny autopietic microbes. In later chapters we shall see more evince of autopoiesis as new complex holons form within the planet's holarchy.
Chapter 4. Problem for Earthlife
Earth had big problems right from the time its dance of life began. In more scientific terms, we might say the probability that Gaia --- our name for Earthlife as a whole --- would continue to evolve was rather low during its early stages. A stable autopoietic Gaian system evolved only under considerable thereat to its existence.
The constant hail of meteors, leaving craters such as we see on the Moon, was a serious threat. Tough meteors may have contributed important molecules such as lipids to the formation of microbes, they might also have killed them off agin. Every day these space rocks of all sizes came hurling from the sky like bullets.
The first microbes seem to have formed on the seafloor, in seawater or wet mud deep to have formed on the seafloor, in seawater or wet mud deep enough to filter out the dangerous rays. Bits of a rich soup of organic molecules and seawater were probably trapped in liposome spheres where the molecules could move about and begin new kinds of chemical cycle. These would have included the construction of the giant RNA and DNA molecules that became useful as a storage system for information life needed.
In the self-production and reproduction cycles that gradually evolved, RNA lined up with DNA to copy its information, then lined up with amino acids to produce the proteins coded for. But giant RNA and DNA molecules could be broken by ultraviolet light, and so one of life's earliest inventions, not long after reproduction itself, was the repair of DNA with special enzymes.
Early microbes were now becoming full-fledged bacteria of the type we call archae, simply meaning ancient. Lipid walls enclosing them permitted the entry of new raw materials and the disposal of wastes. Every living being or system has to cycle and recycle suppose. As Earth's weather cycles circulator water from sky to found and sea and back to sky, rock is dissolved in running water and swept to the sea. Atmospheric gases are also cycled and their balance regulated. The planet's temperature is determined by all these processes, with a strong role played by its variable cloud cover.
The liposome microbes formed in the Earth's crust developed internal cycles for circulating their won supplies and carrying out the business of life. Gradually they replaced their tiny spherical capsules with larger, more flexible cell membranes and evolved into bacteria. By trial and error they learned to use these supplies to grow themselves, to repair themselves when they suffed damage, and to reorganize themselves as needed, keeping records of their new discoveries in their DNA.
Every living creature must get material and energy from its environment to form itself and to keep itself alive. What is left of these supplies after the useful parts have been taken from them is waster that must be gotten rid of by returning it to the creature's environment. This is why no living creature can ever be entirely independent --- it is always a holon within a larger holons, including ecosystems, depending on them for its very life.
As author/scientist/philosopher Arthur Koestler put it, a holon has at once the autonomy of a whole in its own right and dependence of a part embedded within larger holons. Let us call it a holon's holonomy --- the rule of the greater whole (holon) that must be balanced with its self-ruling autonomy.
Physicist David Bohm used the word holonlmy in exactly this sense when describing how the autonomy of every subatomic particle is stabilized and tempered by the rule of all other particles around it --- by its holonomy.
Any holon containing smaller holons, such as a body made of cells, tempers the individual autonomy of its components with its own autonomy, which is their holonomy. For example, individual human must transcend simpleself-rule and integrate himself with the rules of family and society, while human society must transcend its autonomy and integrate itself with the holonomy imposed by the autonomy of the planet.
The balance between any holon's autonomy and holonomy must be worked out as mutual consistency if the holon is to strive as part of a larch, and it cannot survive in any other way if we accept the fundamental notion of mutual consistency.
These concepts of embeddedness or holarchy, and of the autonomy at every level of holachy always tempered by holonomy are extremely important to understanding how life works.
A holon = something that is simultaneously a whole and a part. A part=whole
Holarchy = a whole embedded in a larger whole which is also a part of another whole. Embeddedness
Holonomy = the holon (whole) must be balanced with its smaller holons (self-ruling autonomy) while coping with larger holon.
The rule of life (cooperation/negotiation):
When broken --- wrong boundary (less intelligence/awareness) --- destruction of enemies = destruction of a part of larger whole = cancer = eventual death of a whole (physical level) Creation of negative karma (on metaphysical level)
Earth crust --- cell membrane --- boundary --- the portal ? ---to--- intelligence ?
Bacteria are holons within larger holons consisting of their complex communities and even worldwide networks, as well as within their broader ecosystems. Let us use the term ecosystem to refer to systems of related organisms in their habitats.
Bacteria are technically called monera --- the first kingdom of living things in our present evolutionary classification scheme. Monera include the archae and their later descendants of many types. Each monsoon is a single cell, and yet it is also a whole organism or creature. The tine monera that were Earth's first creatures were thus the first relatively independent holons within the Earth holon
Fortunately for these early monera, the sea was full supply molecules, ranging from small dissolved rock salts to the larger sugar and acid molecules needed to build DNA and protein. So the bacteria could grow and divide and grow again, spreading themselves thickly throughout the seas. As they multiplies, winds and water driven by the sun's energy swirled this rich chemical soup about, stirring it into ever-greater activity. So prolific were these microbes, that their colonies formed entire continental shelves long before corals evolved. Even today, bacteria (monera) are by far the most numerous creatures of the Earth.
The more bacteria there were to suck up supplies and blow out their wastes, the more the whole chemistry of the Earth changed.
Many early monera were getting their energy by breaking up supply molecules in a process we call fermentation. The bacteria we use to make cheese, yogurt, and wine still work the same way today. Yeasts, such as those we use to make bread, do it, too. Fermenting bacteria can be thought of as bubblers, since they make bubbles of waste gases, like the bubbles you see in risen bread and in cheese. Whenever you see bubbles rising in mud or stagnant waters, fermenting bacteria are probably at work.
Breaking up molecules by fermentation or in other ways frees the energy that held them together.
The bubblers stored this energy in a special kind of molecule we call adenosine triphosphate (ATP).
At first they may have hound ready-made ATP molecules in their surroundings, but eventually they learned how to make ATP. The bubblers kept the energy-loaded ATP handy until the energy was needed for building, repair, and other work.
Every living thing on Earth since then has been using the ATP energy storage system invented by the bubblers.
ATP is thus often called the energy currency of life.
In additions to energy, the bubblers needed building supplies, and for a long time, large sugar and acid molecules were plentiful in the environment, ready to be split up or used as they were. To reproduce, some monera copied their DNA and then split themselves down the middle in the process we call mitosis, building two offsprings from their own split halves. Others budded off smaller bits of themselves containing copied DNA to start their offspring. When supplies got low here and there, some bacteria learned to pack their DNA and a bit of protein into solid little spores with tough shells. These spores floated about till they came to places where supplies were plentiful and they could grow into proper monera.
More than 3 billion years ago, then, bubbler monera were multiplying and dividing into different strains, forming a thick soup or surface sum, living off ready-made supplies of large sugar and acid molecules. Some strains of bacteria learned to use the acid and alcohol wastes of others, and to set up efficient cycles of using one another's wastes as supplies. Some learned to use the nitrogen of the atmosphere usable by combining it with other elements. Had they not, life would have died out from nitrogen starvation, as nitrogen is one of the six basic elements needed to build living things.
As competition for large-molecule food supplies increased, a new crisis developed. It began to look as if Gaia's first tiny creatures might die for lack of supplies. But they didn't. Life is far too inventive to give up so easily.
What happened to the monera back then is rather like what is happening to us humans today.
We have been making much of the energy we need to live in our human societies from the coal and oil supplies found ready-made in our environment. Now these supplies are running out, and we must find new ways to produce energy. A very important way of doing so involves the use of Sunlight, or solar energy.
This is exactly what some monera began doing as their supplies ran low. Some elements they had to have in order to build their bodies were all around them, but like the atmospheric nitrogen they were not in usable form. Others were hard to get at, such as the nitrogen locked into the salty nitrates of the sea or the carbon locked up in the carbon dioxide gas of the atmosphere. There were plenty of carbon and nitrogen all around, but the bubbles had to invent special ways to unlock the carbon and nitrogen and then 'fix' them by turning them into usable bodybuilding molecules.
Perhaps the blubbers' most important discovery was finding ways to harness solar energy --- to trap Sunlight and turn it into ATP energy, which they did by using certain light-sensitive chemicals such as the porphyrins that make our blood red and the chlorophyll that makes grass and leaves green.
They could then use this energy to split molecules of carbon dioxide gas, water, and rock salts into atoms which could be rebuilt into food sugars, DNA parts, and more ATP for the work of growing, repairing, and reproducing.
This process is of course, photosynthesis --- (G) 'making with light' --- the use of light in the manufacture of food.
Some of the photosynthesizing monera are called blue-green bacteria because of the color their photosynthesizing chemicals gave them. Let's call them blue greens for short. Their new way of life was very successful, so the multiplied quickly.
After all, the blue-greens, unlike the bubblers, needed no special supplies. Water full of dissolved rock salt was what they lived in, and the atmosphere was full of light and carbon dioxide.
There was only one problem: the bluegreens' wonderful new way of making their own food and energy was also creating pollution.
Both the bubblers and the bluegreens made waste gasses as they worked, but light-making food from water and carbon dioxide gas produced a very poisonous waste --- so poisonous that it killed living things.
This poisonous gas was oxygen! For the first living creatures it was deadly.
It is oxygen that turns metals to rust and makes fires burn. Oxygen destroys the giant molecules of living things, burning them up just as ultraviolet and other kinds of radiation do.
In fact, oxygen is more destructive than ultraviolet, for the large molecules needed to build the first living things could never have formed if the atmosphere had been as rich in oxygen then as it is now.
So, the bluegreen began making oxygen, they began making trouble. Every molecule of carbon dioxide (CO2) is made of 1 carbon atom + 2 oxygen atoms.
Every molecule of water (H2O) is made of 2 hydrogen atoms + 1 oxygen atom.
It takes 6 molecules of carbon dioxide (CO2) and 6 molecules of water (H2O) to make 1 molecule of food sugar.
But when the sugar molecules is built from carbon, hydrogen, and oxygen atoms, it only needs 12 oxygen (O2) molecules, so 6 are left over as waste.
This is the oxygen that began polluting the early Earth after photosynthesis began.
At first the free oxygen combined harmlessly with dissolved rock minerals such as iron, making them rust, and built itself into rock.
When these crustal material had absorbed all they could, the oxygen began piling up in the atmosphere.
It was as if a giant pump had been turned on. They also pumped nitrogen out of nitrate sea salts, fixed some of it for their use, and pumped useless nitrogen gas into the atmosphere. The living Earth was bringing its own special nitrogen-and oxygen-rich atmosphere into being.
Our nearest planet neighbors, Venus and Mars, have atmospheres made entirely of carbon dioxide, just as was Earth's, very likely, when this great pump got going. But now our atmosphere is almost all nitrogen and oxygen --- because life made it so. But how did life survive the poisonous oxygen?
Much of it didn't survive. Some kinds of bubblers that didn't need to be near light dug themselves down into mud where the poisonous oxygen could not get at them. Their fermenter descendants still live today by hiding from oxygen in mud or in other safe places sic as the stomachs of cows, where they help digest hay, or the bead-like root nodules of peas and beans. But many, if not most, kinds of early bacteria must have been killed as the oxygen piled up around them.
It was a lesson Gaia learned more than once, that new experimental forms of life may seriously endanger the whole dance and that other improvisations may be required to rebalance it. Our evolving planet developed the kind of 'body wisdom'.
By this body wisdom, living systems operate and maintain themselves, somehow knowing what to do on a momentary and daily basis as well as in most cases when things go wrong. We are used to it in our bodies and we count on it, but to learn that the Earth behaves the same way is still news to many people.
Though clever species of bubbles survived by hidin from oxygen, they were no longer the main kid of monera. Bluegreens invented enzymes, which made the oxygen they produced harmless to themselves. Some also learned to make ultraviolet Sunscreens, as we make sunglasses and chemicals to protect ourselves from Sunburn. These were able golive successfully in stronger Sunlight, where they could make plenty of food.
Others solved the problem of ultraviolet burn by living together in thick colonies. Those on top were burned to death, but the dead cell made good filters, absorbing the burning rays while letting the rest of the light reach those that needed it below. This was another way in which some lives were given for others, and a good reason for bacteria to levee as cooperative life teams rather than as in depended individuals.
You can see such colonies of bacteria beginning as a greenish brown scum on damp walls or muddy ground. Near the sea, they trap sand and other particles, forming thick muddy masses in shallow waters as live bacteria multiply and keep climbing toward the top. In some places we can still see this mass harden into rocks called stromatolites. In ancient stromatolites, the bacteria that have turned to rockcan still be seen and identified.
Dr. Sahtouris is an evolution biologist, futurist, professor, and consultant on Living Systems Design. She has convened two International Symposia on the Foundations of Science and written about integral cosmologies.
A Walk Through Time: from Stardust to Us
Biology Revisioned, co-authored with Willis Harman
EarthDance: Living Systems in Evolution.
The number of such rock colonies framed billions of years ago, sometimes extending into entire continental shelves, tells us just how successful the oxygen makers have been. This also show clearly how rocks that rearranged themselves into living creatures can rearrange themselves back into rock.
stromatolites = living “rock like” structures range in morphology from flat films to domes and columns. Stromatolites have been traced back over 3.5 billion years to the early Archean period; giving them the title of the longest living and most resilient forms of life on this planet.
For about 2 billion years --- almost half of Earth's life until now --- the bluegreen oxygen makers were her most successful creates. They multiplied into thousands of different kinds all through her waters and muds, making more and more oxygen in their ever-growing colonies. Some of them learned how to use the waste oxygen they created in making food molecules --- they used it to burn those food molecules for energy.
This process of burning food with oxygen is what we call respiration --- the third way of making ATP. It is the most efficient of all. In respiration, the energy of oxygen is used to break up food molecules and thereby free both their parts and their parts and their energy for use. It is a much more powerful way to do this method of using poisonous oxygen to good advantage.
Since we call the intake of oxygen for breaking up or burning good molecules breathing, let's call the new respiring bacteria breathers.
Like fermentation and photosynthesis, respiration produces waste gas. But this time the waste gas is carbon dioxide --- the very gas needed for photosynthesis. What an incredible new opportunity. Respiration completed a cycle by leaving a supply of carbon dioxide with which to start photosynthesis anew.
Looking closely into the green and brown living 'scum' on the tops of stromatolites, or in your kitchen sink, we are astounded.
For the scum, often containing vast numbers of bubblers, bluegreens and breathers, resolved itself into the most amazing cityscapes populated by all sorts of bacteria doing different tasks cooperatively while living different lifestyles.
These cities look like Manhattan's skyscrapers, as one scientist put it. Our ancient bacterial forbears built infrastructures for their communities much as we do today.
The developing world of bubblers, bluegreens, and breathers in the great Bacterial Age made its progress through many technological inventions. Several of our greatest recent technological advances, such as genetic engineering, were learned from them. Bacteria discovered this process, actually the secret of their wild success, billions of ears ago.
Scientific research has shown for over half a century, beginning with Barbara McClintock's work on corm plants, that DNA reorganizes intelligently in response to specific problems faced by living organisms. It happens in life forms from microbes to very large multi celled creatures.
Evolution was only supposed to proceed by accident and 'selection.' But now many scientists see that many DNA changes are anything but accidental.
Modern bacteria have obviously been able to change very quickly in ways that protect them against our lethal antibiotics.
To do this, they have to make changes in their DNA. How do bacteria do it?
With modern microscope, we can see that bacteria come very close to one another and then dissolve parts of their cell walls to create a hole, then exchange bits of DNA.
One or both of them leaves this encounter with a new combination of DNA though no reproduction had taken place.
This information exchange system of bacteria is what made the rest of their innovation possible. We are just beginning to learn how it works and to recognize it as original sex.
Sex is by definition the production of creatures by a combination of DNA from more than one individual. Every time bacteria receive bits of DNA called genes from others, they are engaging in sex by making themselves the product of two bacterial sources even though they are not reproducing.
This sexual communication system apparently belongs to virtually all bacteria of all strains, so that bacteria trade their DNA genes with one another all over the Earth.
Thus these tiny ancient beings actually created the fist World Wide Web of information exchange, trading genes as we trade our own messages.
All bacteria can be thought of as one great holon with a common pool of DNA genes --- system covering our entire planet. And their 'Internet' probably includes larger creatures, including ourselves, as bacteria coming into plants and animals to trade bits of DNA.
The young Earth's bacterial been pool (web) made it possible to spread resistance to oxygen by sharing blueprints for various protective devices. Of all Gaia's creatures, the blue-green breathers that harnessed solar energy were the most independent ever to evolve, and they are still going strong today,
The recycling of carbon dioxide and oxygen that began with them was so successful that it has been an essential part of the Gaian life system ever since. The two parts of this cycle --- photosynthesis and respiration --- became ways of life for different kinds of one-celled creatures. Then much later plants and animals evolved to cooperate in producing carbon dioxide and oxygen for each other's use.
3. respiration of the breathers, 2. photosynthesis of the bluegreens, 1. fermentation of the bubblers,
We are reminded of lessons people are learning today. First the ancient bacteria solved their energy crisis by developing solar technology, then they discovered that recycling supplies is the best way to avoid running out of them.
As the oxygen piled up in and thickened the atmosphere, it not only created new problems requiring new solutions, but was itself a solution to the old problem of ultraviolet burn. Oxygen helped form a protective blanket of air around the living Earth. Just as our ancient myth Gaia first formed the seas in her dance of life and then created a protective atmosphere, so it was in reality.
From this early history of the Gaian dance of life we can wee that great problems are great challenges, and that living things are very inventive when faced with challenges. Maybe that is one of the most important things we can learn from evolution.
It remains to be seen whether we humans will brave as creative as ancient bacteria in the face of the problems we create. Over billions of years, most of the carbon dioxide was pumped from Earth's atmosphere by photosynthesis, while nitrogen, oxygen, and rarer gases produced by living creatures replenished it. Over this long time, life worked out exactly the right balance of gases that was best for it. Now we are changing that balance in dangerous way. Atmospheric carbon dioxide is rapidly approaching levels it apparently reached previously just before the ice ages. Gaia may cool her man-made fever with a new ice age, destroying most of what we ave built and forcing us into retreat. We know humans have survived a number of them by moving to the tropics where new land is exposed. Far worse would be Gaia's other alternative: to reset her thermostat at a higher temperature. Humans, other land animals, trees and other land life would all succumb to the increased heat and the loss of almost all dry land if polar caps melted and oceans rose dramatically in a heat age.
This is what we are learning: to understand that the Gaian life system has evolved in such a way that it takes care of itself as a whole, and that we humans are only one part of it. Gaia goes on living, that is while her various species coma and go. Whatever we do that is not good for life, the rest of the system will try to balance in any way it can. That is why we must learn Gaia's dance and follow its rhythm and harmonies in our own lives.
Elisabet Sahtouris : evolution biologist