By James Lovelock - Lynn Margulis
When Lovelock published the Gaia hypothesis, it shocked many scientists, especially those with a more logical mind who hated a concept that sounded so mystical. It puzzled them, and most puzzling of all was that Lovelock was one of them.
Formulation of the Gaia Hypothesis
Global vision of the primitive terrestrial
First investigations of extraterrestrial life
In search of evidence of extra-terrestrial life, especially in the nearest planets, the North American Space Agency NASA, http://www.nasa.gov, began its investigations on Venus and Mars. Research on Mars took priority due to the unknown and difficult conditions in the atmosphere of the planet Venus. The first spacecraft to visit Mars was Mariner 4 in 1965 and several others followed including the two Vikings in 1976.
Dr. James Lovelock, a British chemist specializing in atmospheric sciences, invented an electron capture detector, capable of tracking extremely small amounts of matter in gases, and which was used to study the effects of CFC on the formation of air. hole in the ozone layer in our atmosphere in the early 1970s. A decade later, NASA and the JET Propulsion Laboratory requested the presence of Lovelock for their research project of evidence of life on Mars.
Earth, a singular planet
In collaboration with other researchers, Lovelock predicted the absence of life on Mars based on considerations of its atmosphere and its dead chemical equilibrium state. In contrast, the Earth's atmosphere is described in a chemical state very far from that equilibrium. The rare balance of atmospheric gases on Earth is unique in our solar system. This fact could be clearly visible to any extraterrestrial observer, by comparing the images of the planets Venus, Earth and Mars.
And this could be realized in the last decades of the second millennium: man travels through interplanetary space and through imaging technology, he in fact becomes an extraterrestrial observer!
In this regard, Lovelock asked himself the following question: Why is Earth different?
Analyzes show that both Venus and Mars have about 95% Carbon Dioxide in their atmosphere and very little Oxygen and Nitrogen. What has happened over billions of years to explain this significant difference? How did this condition come about and how has this balance, which is chemically far removed from its death balance, managed to be maintained?
By the end of 1960, Lovelock had already taken the first steps to answer this question by considering the beginnings of life on planet Earth:
About 3 billion years ago, in the oceans, bacteria and photosynthetic algae extracted carbon dioxide from the atmosphere, releasing oxygen. Gradually, throughout the vast geological times, the content of the atmosphere was changing, from a domain of carbon dioxide to the domain of a mixture of nitrogen and oxygen, capable of supporting organic life sustained by aerobic combustion, such as animals and man do.
The Gaia hypothesis
We would all like to believe that there is something (some kind of higher and good being) that can step in and save us from the things that go wrong in our world.
Most people have always had such a comforting belief. For most of human history, the candidate for this "something" has been God (it does not matter which god is worshiped in which time and place) and that is the reason why, in dry summers, farmers have raised their prayers for rain. They continue to do so, but as scientific knowledge increases and more and more explanations for events are found from natural laws rather than divine whim, many people begin to desire a less supernatural (and perhaps more predictable) protector. .
That's why there was quite a stir in the scientific community when, some forty years ago, a British scientist named James Lovelock proposed something that met these requirements. Lovelock gave a name to his hypothetical new concept: he named it Gaia, after the ancient goddess of the earth.
When Lovelock published the Gaia hypothesis, it shocked many scientists, especially those with a more logical mind who hated a concept that sounded so mystical. It puzzled them, and most puzzling of all was that Lovelock was one of them. He had a reputation for being somewhat non-conformist, but his scientific credentials were very strong. Among other achievements, Lovelock was known for being the scientist who had designed the instruments for some of the experiments to search for life that the American ship Viking had carried out on the surface of Mars.
And yet, in the eyes of his peers, what Lovelock was saying bordered on superstition. Worse still, he was reckless in presenting his arguments in the form of an orthodox "scientific method." He had obtained the evidence for his proposal from observation and scientific literature, as a scientist is supposed to do ... According to him, the evidence showed that the entire biosphere of planet earth (or what is the same, until the last living being that inhabits our planet, from bacteria to elephants, whales, redwoods and you and me) could be considered as a single organism on a planetary scale in which all its parts were almost as related and independent as cells of our body. Lovelock believed that this collective super being deserved a name of its own. Lacking inspiration, he turned to his neighbor, William Golding (author of Lord of the Flies) for help, and Golding came up with the perfect answer. So they named it Gaia.
Lovelock came to this conclusion in the course of his scientific work while trying to devise what signs of life the instruments they were designing should look for on the planet Mars. It occurred to him that if he were a Martian instead of an Englishman, it would have been easy to solve the problem in the opposite direction. To get the solution, all a Martian would have needed would have been a modest telescope with a good built-in spectroscope. The very composition of the Earth's air proclaims the undeniable existence of life. The Earth's atmosphere contains a large amount of free oxygen, which is a very active chemical element. The fact that it is free in these amounts in the atmosphere means that there must be something that is constantly replenishing it. If this were not the case, atmospheric oxygen would have reacted a long time ago with other elements such as iron on the earth's surface and would have disappeared, just as our terrestrial spectroscopes have shown that whatever amount of oxygen there might have been has been used up. long overdue in our planetary neighbors, Mars included.
Therefore, a Martian astronomer would have understood immediately that this "something" that replenishes oxygen could only be one thing: life.
It is life (living plants) that constantly produces this oxygen in our air; life (us and almost all living beings in the animal kingdom) count on it to survive.
Starting from this, Lovelock's idea is that life (all life on earth as a whole) interacts and has the ability to maintain its environment in such a way that the continuity of its own existence is possible. If some environmental change were to threaten life, it would act to counteract the change in much the same way as a thermostat acts to keep your home comfortable when the weather changes by turning on the heating or air conditioning.
The technical term for this type of behavior is homeostasis. According to Lovelock, Gaia (the collection of all life on earth) is a homeostatic system. To be more precise from a technical point of view, in this case, the appropriate term is “homeoretic” instead of “homeostatic”, but the distinction can only be of interest to specialists. This self-conserving system not only adapts to change, it even makes its own changes by altering its environment whenever necessary for its well-being.
Stimulated by these hypotheses, Lovelock began to search for other tests of homeostatic behavior. He found them in unexpected places.
In the coral islands, for example. Coral is made up of living animals. They can only grow in shallow water. Many coral islands are slowly sinking, and somehow the coral continues to grow upward as long as it needs to stay at the proper depth to survive. This is a rudimentary type of homeostasis. There is also the temperature of the Earth. The global average temperature has remained within fairly narrow limits for a billion years or more, although it is known that during this time the solar radiation (which is what basically determines this temperature) has been continuously increasing. Therefore, the warming of the earth should have been noticed, but it has not been. How could this have happened without some kind of homeostasis?
Even more interesting to Lovelock was the paradoxical question of the amount of salt in the sea. The current concentration of salt in the planet's oceans is just right for the marine plants and animals that live in them. Any significant increase would be disastrous. It takes a great effort for fish (and other marine life-styles) to prevent salt from accumulating in their tissues and poisoning them; If there were much more salt in the sea than there is, they would not be able to do it and they would die. And yet, by all normal scientific logic, the seas should be much saltier than they are. Rivers on Earth are known to continually dissolve salts from the soils through which they flow and transport them in large quantities to the seas. The water that rivers add each year does not stay in the ocean. This pure water is eliminated by evaporation due to solar heat, to form clouds that end up falling again as rain; while the salts that these waters contained have nowhere to go and are left behind.
In this case, daily experience teaches us what happens. If we leave a bucket of salty water in the sun during the summer, it will become more and more salty as the water evaporates. Although it may seem surprising, this does not happen in the ocean. Its salt content is known to have remained constant throughout the entire geological period.
So it is clear that something works to remove excess salt in the sea.
A process is known that could be responsible. From time to time, the shallow bays and arms of the sea become isolated. The sun evaporates the water and saline beds remain that over time are covered by dust, clay and, finally, impenetrable rock, so that when the sea returns to recover the area, the fossil salt layer is sealed and does not redissolve. Later, when people mine it for their needs, we call it a salt mine. In this way, millennium after millennium, the oceans get rid of excess salt and maintain their saline concentration.
It could be a simple coincidence that this balance is maintained with such precision, regardless of what happens, but it could also be another manifestation of Gaia.
But perhaps Gaia shows herself more clearly in the way she has kept Earth's temperature constant. As we have already said, at the origins of the earth, solar radiation was a fifth of that of today. With so little sunlight to warm up, the oceans should have frozen, but that did not happen.
The reason is that at that time the Earth's atmosphere contained more carbon dioxide than today and this, says Lovelock, is a matter of Gaia, since plants appeared to reduce the proportion of carbon dioxide in the air. As the sun warmed up, carbon dioxide, with its heat-retaining properties, decreased in exactly the right measure over millennia. Gaia acted through plants (indicates Lovelock) to keep the world at the optimum temperature for life.
Text taken from "The Wrath of the Earth", written by Isaac Asimov and Frederik Pohl
The GAIA Theory: Earth as a Living Planet
Greenhouse effect, ozone hole, acid rain ... the blows that this planet has to endure. So far it has protected us and provided everything we needed: heat, land, water, air. And your good work has cost you. It took millions of years to turn a hell of fire and ash into a paradise of oceans, mountains and oxygen, overcoming many vicissitudes in the form of meteorite collisions, displacement of continents and brutal ice ages. And now, Gaia, the Great Mother, has to suffer the slaps of her own favorite children, men.
Yes, Gaia, the one with the wide bosom, eternal and unbreakable support of all things, the one who was goddess of the Earth for the ancient Greeks, is a living organism. Our entire planet is a living organism, superbly gifted to give birth to the optimal environmental conditions for the development of plants and animals. Or at least that postulates the extraordinary scientific theory formulated by the English biochemist James Lovelock.
In this monograph I will develop this conception of the aforementioned scientist, and will try to highlight its importance as a theoretical support for a planned ecological activity that allows saving the Earth and its inhabitants from total destruction.
Development - The Gaia Theory: The Earth as a Living Planet
The idea of considering the Earth as a living being is risky, but not far-fetched. However, when in 1969 Lovelock officially presented his Gaia hypothesis in the framework of a scientific conference held in Princeton (United States), he did not find any echo among the scientific community.
Except for the North American biologist Lynn Margulis - with whom she would later collaborate - no researcher was interested in such an amazing theory. For the vast majority, Gaia was nothing more than an entelechy, an interesting exercise of imagination. Who would have believed that our planet is a kind of superorganism in which, through physicochemical processes, all living matter interacts to maintain ideal living conditions! Some even accused him of being a fraud. Possibly because, although irrelevant, that fantastic vision of the world that Lovelock offered was, if not dangerous, at least disturbing.
The Gaia hypothesis not only contradicted most of the preceding scientific postulates and turned upside down the theoretical models held as valid. Above all, they supposed to put into question Darwin's untouchable and sacrosanct Theory of Evolution: throughout history life has adapted to the conditions of the physicochemical environment. Lovelock proclaimed just the opposite: the biosphere - a group of living beings that populate the surface of the planet - is in charge of generating, maintaining and regulating its own environmental conditions. In other words, life is not influenced by the environment. It is she herself that exerts an influence on the world of the inorganic, so that there is a coevolution between the biological and the inert. A real scientific bombshell for that time!
But the bomb did not go off. Except for provoking the angry protests of the most radical scientists ascribed to the classical doctrines, the Gaia hypothesis fell on deaf ears. And then into oblivion, until recently they have begun to dust it off and review the validity of their postulates, perhaps forced by the current crisis that the planet is suffering. Although its existence has not yet been proven, Gaia has already proven its theoretical value by giving rise to many questions and, more importantly, by offering coherent answers to the most curious unknowns on Earth.
What can we imagine after that eccentric assumption baptized as Gaia? The starting point of the hypothesis was the contemplation, for the first time in the history of mankind, of the globe from outer space. The ships and probes sent to Mars and Venus in the sixties to investigate and detect possible signs of life and did not find any biological vestige. Instead, they did discover that the pale colors of neighboring planets contrast dramatically with the blue-green beauty of our home, because their atmospheres are radically different from Earth's.
Our transparent envelope of air is a singularity, almost a miracle, compared to the atmospheres that cover neighboring planets. The results of space investigations established that both are composed almost exclusively of carbon dioxide and a minimal percentage of nitrogen. The most abundant constituent of the blue skin that surrounds us is, on the contrary, nitrogen (79 percent), followed by oxygen (21 percent), while the amount of carbon dioxide does not exceed 0.03 percent. To these elements it would be necessary to add traces of other gases, such as methane, argon, nitrous oxides, ammonia, and so on. Quite a strange mix!
But in addition to being a singularity within the Solar System, our atmosphere behaves in a less orthodox way from the chemical point of view. Consider, for example, the simultaneous presence of methane and oxygen, two gases that chemically react in sunlight to form carbon dioxide and water vapor. The coexistence of nitrous oxide and ammonia is just as anomalous as the previous one.
Earth's atmospheric composition represents a gross violation of the rules of chemistry, and it still works. Why? Lovelock discovers in the permanent imbalance between the atmospheric gases one of the first evidence of Gaia's intervention, of the influence that the biological exerts on the inorganic. As in an inert environment such a strange gas mixture would be very unlikely, the only feasible explanation is a daily manipulation from the earth's surface itself. According to the Gaia hypothesis, then, the atmosphere would not be healthy for life on Earth if the biosphere, that biological strip that surrounds the planet, did not take charge of keeping it in condition, constantly exchanging regulatory substances between one medium and another.
Lovelock wondered how the atmosphere could transport those substances that the biosphere takes in on one side and expels it on the other. Did this not presuppose the presence of compounds that carry essential elements - such as iodine and sulfur, for example - among all biological systems? His curiosity spurred an active search for such compounds.
In 1971 he left for Antarctica aboard the British oceanographic sailboat Shackleton, with the purpose of investigating the world sulfur cycle, detecting a component unknown until then, but potentially important: dimethyl sulfide. Later studies revealed that the main source of this substance is not in the open sea but in coastal waters, rich in phytoplankton. Indeed, marine microflora, even the most common species of algae, manage to extract sulfur from sulfate ions present in seawater with amazing efficiency, transforming it into dimethyl sulfide. It was also found that this gas, released into the atmosphere, stimulates the formation of condensation nuclei for water vapor, which in turn increases the cloud concentration.
In 1987, Lovelock stated that the cycle of activity of algae is the one that has ultimately determined the temperature of the earth throughout history. How do you get it? What is its mechanism? Scientists have been able to measure a higher concentration of dimethyl sulfide in the warmer ocean basins, as that is where algae grow best. The presence of a high level of this gas stimulates the formation of cloudy masses that, logically, darken the surface allowing temperatures to drop. But in the same way that heat makes algae grow and multiply in the oceans, cold makes their proliferation difficult, therefore the production of dimethyl sulfide decreases, fewer clouds form and a new thermal escalation begins. Gaia's self-regulation when it comes to temperature is served.
Precisely the history of the Earth's climate is one of the most powerful arguments in favor of the existence of Gaia. Throughout the evolution of the Earth, it has never been unfavorable to life. The biosphere has been able to maintain the most appropriate climatological status quo to safeguard our well-being and provide us with the optimal environment. The paleontographic record of the uninterrupted presence of beings on the planet for 3,500 million years attests to this, at the same time that it indicates the impossibility of the oceans ever boiling or freezing. If the earth was more than an inanimate solid object, the temperature of its surface would have followed the oscillations of solar radiation without possible protection. However, it was not.
It is known that, in the very remote epoch in which life arose, the Sun was smaller and warmer and its radiation was thirty percent less intense. Despite this, the climate was favorable for the appearance of the first bacteria: it was not thirty percent colder, which would have meant a planet devastated by eternal ice. Carl Sagan and his collaborator George Mullen have suggested as an explanation the presence in our ancestral atmosphere of greater amounts of ammonia and carbon dioxide than today, with the function of 'covering' the surface of the planet, both gases help to conserve the heat received, preventing, through the greenhouse effect, that it escapes into space.
When the intensity of the radiation increased, as the Sun increased in size, the appearance of organisms that devour ammonia and carbon dioxide would have dissolved this protective blanket, so that excess heat could be dissipated into space. The knew hand of Gaia is glimpsed here again: the biosphere itself was transforming, in its favor, environmental conditions. Life is thus revealed as a fabulous active control system that automatically regulates the weather conditions, in such a way that it is never an obstacle to its existence.
Along with a mild climate, it is also necessary that other parameters remain within favorable margins. For example, the pH, the degree of acidity of the air, the water, the earth remains around a neutral value (pH 8), the optimum for life, despite the fact that the large amount of acids produced by oxidation in the atmosphere of the nitrous and sulfurous oxides released by the decomposition of organic matter should have increased the earth's acidity to a pH of 3, comparable to vinegar. However, nature has a biological neutralizer to prevent this from happening: the biosphere is responsible for manufacturing, through the metabolic processes of living beings, around 1,000 megatons per year of ammonia - a very alkaline substance-, which results be the amount necessary to cancel the excessive accumulation of aggressive acids.
Tight regulation of marine salinity is as essential to life as chemical neutrality. How is it possible that the average saline level does not exceed 3.4 percent, when the amount of salts that rain and rivers carry into the oceans every 80 million years is identical to all that currently contained in them? Had this process continued, the ocean water, completely saturated with salt, would have become deadly to any form of life. Why then are the seas not saltier? Lovelock assures that, from the beginning of life, salinity has been under biological control: Gaia has served as an invisible filter to make salt disappear to the same extent that it receives it.
This incredible balance that exists between the inert and the living and that makes up the unity of the planet as a system, must be preserved. The science of ecology warns us of this, and urges us to take preventive measures so that our planet is not destroyed.
Pianka Eric, "Evolutionary ecology", Ediciones Omega, Barcelona, 1982.
World Commission for Environment and Development, "Our common future", Alianza Editorial, Madrid, 1989.
Moriarty F., "Ecotoxicology". The study of pollutants in ecosystems ”, Editorial Academia, León, Madrid, 1985.
* Neuquina Ecological Foundation (FUNDEN)