Our planet is unique. Just as each of us is different from the stone statues of the Roman gods, the Earth is different from Mars, Venus and other known planets. Let's tell the story of one of, perhaps, the most amazing and controversial hypotheses of our time - the Gaia hypothesis, which invites us to look at the Earth as a living organism.
Earth is our "smart home"
James Ephraim Lovelock celebrated his centenary last summer. Scientist, inventor, engineer, independent thinker, a person known not so much for his inventions as for the amazing assumption that the Earth is a self-regulating superorganism that, for most of its history, the last three billion years, has maintained favorable conditions for life on the surface …
Named for Gaia - the goddess of ancient Greek mythology, personifying the Earth - the hypothesis, unlike traditional sciences, suggests that the global ecosystem of the planet behaves like a biological organism, and not like an inanimate object governed by geological processes.
In contrast to the traditional earth sciences, Lovelock proposes to consider the planet not as a set of separate systems - the atmosphere, lithosphere, hydrosphere and biosphere - but as a single system, where each of its components, developing and changing, influences the development of other components. Moreover, this system is self-regulating and, like living organisms, has mechanisms of inverse relationship. Unlike other known planets, by using inverse relationships between the living and inanimate worlds, the Earth maintains its climate and environmental parameters in order to remain a favorable home for living beings.
From the very moment of its appearance, this idea was rightly criticized and was not accepted by the scientific community, which does not prevent it, however, from exciting the imagination and collecting many supporters around the world. Despite the centenary, Lovelock now, like most of his long life, remains under the fire of criticism, continues to defend the theory, modifies and complicates it, continues to work and engage in scientific activities.
Is there life on Mars
But before turning his attention to life on Earth, James Lovelock was busy looking for life on Mars. In 1961, just four years after the USSR launched the first artificial satellite of our planet into space, Lovelock was invited to work at NASA.
As part of the Viking program, the agency planned to send two probes to Mars to study the planet and, in particular, to search for traces of the vital activity of microorganisms in its soil. It was the devices for detecting life, which were supposed to be installed on board the probes, that the scientist developed, working in Pasadena, at the Jet Propulsion Laboratory, a research center that creates and maintains spacecraft for NASA. By the way, he literally worked side by side - in the same office - with the famous astrophysicist and popularizer of science Karl Sagan.
His job was not purely engineering. Biologists, physicists and chemists worked alongside him. This allowed him to dive headlong into experiments to find ways to detect life and look at the problem from all sides.
As a result, Lovelock asked himself: "If I myself were on Mars, how could I understand that there is life on Earth?" And he answered: "According to her atmosphere, which defies any natural expectations." Free oxygen makes up 20 percent of the planet's atmosphere, while the laws of chemistry say that oxygen is a highly reactive gas - and all of it must be bound in various minerals and rocks.
Lovelock concluded that life - microbes, plants and animals, constantly metabolizing matter into energy, converting sunlight into nutrients, releasing and absorbing gas - is what makes the Earth's atmosphere what it is. In contrast, the Martian atmosphere is virtually dead and in low-energy equilibrium with almost no chemical reactions.
In January 1965, Lovelock was invited to a pivotal meeting on the search for life on Mars. In preparation for an important event, the scientist read a short book by Erwin Schrödinger "What is Life". That same Schrödinger - a theoretical physicist, one of the founders of quantum mechanics and the author of the well-known thought experiment. With this work, the physicist made a contribution to biology. The last two chapters of the book contain Schrödinger's reflections on the nature of life.
Schrödinger proceeded from the fact that a living organism in the process of existence continuously increases its entropy - or, in other words, produces positive entropy. He introduces the concept of negative entropy, which living organisms must receive from the outside world in order to compensate for the growth of positive entropy, leading to thermodynamic equilibrium, and therefore to death. In a simple sense, entropy is chaos, self-destruction and self-destruction. Negative entropy is what the body eats. According to Schrödinger, this is one of the main differences between life and inanimate nature. A living system must export entropy to keep its own entropy low.
This book inspired Lovelock to ask: "Wouldn't it be easier to search for life on Mars, looking for low entropy as a planetary property, than to burrow into regolith in search of Martian organisms?" In this case, a simple atmospheric analysis using a gas chromatograph is sufficient to find low entropy. Therefore, the scientist recommended NASA save money and cancel the Viking mission.
To the stars
James Lovelock was born on July 26, 1919 in Letchworth, a small town in Hertfordshire in the south-east of England. This city, built in 1903 60 kilometers from London and is part of its green belt, was the first settlement in Great Britain, founded in accordance with the urban planning concept of the "garden city". At the beginning of the last century, it was the idea that captured many countries about the megacities of the future, which would combine the best properties of a city and a village. James was born into a working class family, his parents had no education, but they did everything for their son to receive it.
In 1941, Lovelock graduated from the University of Manchester - one of the leading British universities among the famous "Universities of red brick". There he studied with Professor Alexander Todd, an outstanding English organic chemist, Nobel Prize laureate for the study of nucleotides and nucleic acids.
In 1948, Lovelock received his M.D. from the London Institute of Hygiene and Tropical Medicine. During this period of his life, the young scientist is engaged in medical research and invents the instruments necessary for these experiments.
Lovelock was distinguished by a very humane attitude towards laboratory animals - to the point that he was ready to conduct experiments on himself. In one of his studies, Lovelock and other scientists looked for the cause of damage to living cells and tissues from frostbite.The experimental animals - the hamsters on which the experiment was carried out - were to be frozen, and then warmed and brought back to life.
But if the freezing process was comparatively painless for animals, then defrosting suggested that the rodents needed to put red-hot tablespoons on their chests in order to warm their hearts and force blood to circulate through the body. It was an extremely painful procedure. But unlike Lovelock, his fellow biologists did not feel sorry for laboratory rodents.
Then the scientist invented a device that had almost everything that you can expect from an ordinary microwave oven - in fact, this was it. You could put a frozen hamster there, set a timer, and after a set time he woke up. One day, out of curiosity, Lovelock warmed up his lunch in the same way. However, he did not think to get a patent for his invention in time.
In 1957, Lovelock invents the electron capture detector, an extraordinarily sensitive device that revolutionized the measurement of ultra-low concentrations of gases in the atmosphere and, in particular, in the detection of chemical compounds that pose a threat to the environment.
In the late 1950s, the device was used to demonstrate that the planet's atmosphere was full of residues from the pesticide DDT (dichlorodiphenyltrichloroethane). This extremely effective and easy-to-obtain pesticide has been widely used since World War II. For the discovery of its unique properties, the Swiss chemist Paul Müller was awarded the Nobel Prize in Medicine in 1948. This award was awarded not only for the saved crops, but also for the millions of lives saved: DDT was used during the war to combat malaria and typhus among civilians and military personnel.
It was only by the end of the 50s that the presence of a dangerous pesticide was discovered almost everywhere on Earth - from penguin liver in Antarctica to breast milk of nursing mothers in the United States.
The detector made it possible to obtain accurate data for the writing of the book "Silent Spring" by the American ecologist Rachel Carson in 1962, with which the international campaign to ban the use of DDT began. The book argued that DDT and other pesticides caused cancer and that their use in agriculture posed a threat to wildlife, especially birds. The publication was a landmark event in the environmental movement and caused a wide public outcry, which ultimately led to the ban of agricultural use of DDT in the United States in 1972 and then around the world.
A little later, after starting work at NASA, Lovelock went to Antarctica and with the help of his detector discovered the ubiquitous presence of chlorofluorocarbons - artificial gases that are now known to deplete the stratospheric ozone layer. Both of these discoveries were extremely important for the planet's environmental movement.
So when, by the early 1960s, the US Aeronautics and Space Administration planned their lunar and planetary missions and began looking for someone who could create sensitive equipment that could be sent into space, they turned to Lovelock. Having been fascinated by science fiction since childhood, he accepted the offer with enthusiasm and, of course, could not refuse.
Planets living and dead
Work at the Jet Propulsion Laboratory provided Lovelock with an excellent opportunity to receive the first evidence of the nature of Mars and Venus transmitted by space probes. And these were, undoubtedly, completely dead planets, strikingly different from our flourishing and living world.
The earth has an atmosphere that is thermodynamically unstable.Gases such as oxygen, methane and carbon dioxide are produced in large quantities but coexist in stable dynamic equilibrium.
The strange and unstable atmosphere we breathe requires the presence of something on the surface of the Earth that can continuously synthesize huge amounts of such gases, as well as simultaneously remove them from the atmosphere. At the same time, the planet's climate is quite sensitive to the abundance of polyatomic gases such as methane and carbon dioxide.
Lovelock gradually develops an idea of the regulatory role of such cycles of substances in nature - by analogy with metabolic processes in the body of an animal. And earthly life is involved in these processes, which, according to Lovelock's theory, not only participates in them, but also learned to maintain the necessary conditions of existence for itself, having entered into some form of mutually beneficial cooperation with the planet.
And if at first all this was pure speculation, then in 1971 Lovelock had the opportunity to discuss this topic with the outstanding biologist Lynn Margulis, the creator of the modern version of the theory of symbiogenesis and the first wife of Carl Sagan.
Margulis co-authored the Gaia hypothesis. She suggested that microorganisms should play a connecting role in the field of interaction between life and the planet. As Lovelock noted in one of his interviews, "It would be fair to say that she put flesh in the bones of my physiological concept of a living planet."
Due to the novelty of the concept and its inconsistency with traditional sciences, Lovelock needed a short and memorable name. It was then, in 1969, a friend and neighbor of the scientist, physicist and writer, Nobel Prize laureate, and author of the novel Lord of the Flies, William Golding, proposed to call this idea Gaia - in honor of the ancient Greek goddess of the Earth.
How it works
According to Lovelock's concept, the evolution of life, that is, the totality of all biological organisms on the planet, is so closely related to the evolution of their physical environment on a global scale that together they form a single self-developing system with self-regulatory properties similar to the physiological properties of a living organism.
Life doesn't just adapt to the planet: it changes it for its own purposes. Evolution is a pair dance in which everything living and inanimate is spinning. From this dance the essence of Gaia emerges.
Lovelock introduces the concept of geophysiology, which implies a systems approach to earth sciences. Geophysiology is presented as a synthetic earth science that studies the properties and development of an integral system, the closely related components of which are biota, atmosphere, oceans and the earth's crust.
Its tasks include the search and study of self-regulation mechanisms at the planetary level. Geophysiology aims to establish links between cyclic processes at the cellular-molecular level with similar processes at other related levels, such as the organism, ecosystems and the planet as a whole.
In 1971, it was suggested that living organisms are capable of producing substances that have regulatory significance for the climate. It was confirmed when, in 1973, the emission of dimethyl sulfide from dying planktonic organisms was discovered.
Droplets of dimethyl sulfide, entering the atmosphere, serve as nuclei of condensation of water vapor, causing the formation of clouds. The density and area of cloud cover significantly affect the albedo of our planet - its ability to reflect solar radiation.
At the same time, falling to the ground along with the rain, these sulfur compounds promote plant growth, which, in turn, accelerate the leaching of rocks. The biogens generated by leaching are washed into rivers and eventually end up in the oceans, promoting the growth of planktonic algae.
The cycle of travel of dimethyl sulfide is closed.In support of this, it was found in 1990 that cloudiness over the oceans correlates with the distribution of plankton.
According to Lovelock, today, when the atmosphere is overheated as a result of human activity, the biogenic mechanism of regulation of the cloud cover becomes extremely important.
Another regulatory element of Gaia is carbon dioxide, which geophysiology considers as a key metabolic gas. Climate, plant growth and production of free atmospheric oxygen depend on its concentration. The more carbon is stored, the more oxygen is released into the atmosphere.
By controlling the concentration of carbon dioxide in the atmosphere, biota thereby regulates the average temperature of the planet. In 1981, it was suggested that such self-regulation occurs through biogenic enhancement of the weathering process of rocks.
Lovelock compares the difficulty in understanding the processes occurring on the planet with the difficulty in understanding the economy. The eighteenth century economist Adam Smith is best known for introducing the concept of the "invisible hand" into scholarship, which makes unbridled commercial self-interest somehow work for the common good.
It is the same with the planet, says Lovelock: when it “matured,” it began to maintain conditions suitable for the existence of life, and the “invisible hand” was able to direct the disparate interests of organisms to the common cause of maintaining these conditions.
Darwin vs. Lovelock
Published in 1979, Gaia: A New Look at Life on Earth became a bestseller. It was well received by environmentalists, but not by scientists, most of whom rejected the ideas it contained.
Renowned critic of creationism and intelligent design, University of Oxford professor and author of The Selfish Gene, Richard Dawkins, condemned Gaia's theory as a "deeply flawed" heresy against the basic tenet of Darwinian natural selection: "the fittest survives." Still, because Gaia's theory states that animals, plants and microorganisms not only compete, but also cooperate to maintain the environment.
When Gaia's theory first began to be discussed, Darwinian biologists were among her fiercest opponents. They argued that the cooperation necessary for the self-regulation of the Earth can never be combined with the competition necessary for natural selection.
In addition to its essence, the name, taken from mythology, also caused dissatisfaction. All this looked like a new religion, where the Earth itself became the subject of deification. The talented polemicist Richard Dawkins challenged Lovelock's theory with the same energy he later used in relation to the concept of the existence of God.
Lovelock went on to refute their criticism with evidence of self-regulation gathered from his research and mathematical models that illustrated how planetary climate self-regulation works. Gaia's theory is a top-down, physiological view of the Earth system. She views Earth as a dynamically responsive planet and explains why it is so different from Mars or Venus.
The criticism was mainly based on the misconception that the new hypothesis was anti-Darwinian.
"Natural selection favors enhancers," Lovelock said. His theory only details Darwin's theory, implying that nature favors organisms that leave the environment in better shape for offspring to survive.
Those species of living things that negatively affect the environment, make it less suitable for posterity and will eventually be expelled from the planet - as well as weaker, evolutionarily unadapted species, Lovelock argued.
Copernicus waiting for his Newton
Summing up, it must be said that the scientific concept of the Earth as an integral living system, a living superorganism has been developed by naturalistic scientists and thinkers since the 18th century. This topic was discussed by the father of modern geology and geochronology James Hutton, natural scientist who gave the world the term "biology" Jean-Baptiste Lamarck, naturalist and traveler, one of the founders of geography as an independent science, Alexander von Humboldt.
In the 20th century, the idea was developed in a scientifically grounded concept of the biosphere of the outstanding Russian and Soviet scientist and thinker Vladimir Ivanovich Vernadsky. In its scientific and theoretical part, the concept of Gaia is similar to the "Biosphere". However, in the 70s of the last century, Lovelock was not yet familiar with the works of Vernadsky. At that time, there were no successful translations of his work into English: as Lovelock put it, English-speaking scientists are traditionally "deaf" to work in other languages.
Lovelock, like his longtime colleague Lynn Margulis, no longer insists that Gaia is a superorganism. Today he recognizes that, in many ways, his term "organism" is just a useful metaphor.
However, Charles Darwin's concept of “struggle for survival” can be considered a metaphor with the same reason. At the same time, this did not prevent Darwinian theory from conquering the world. Metaphors like these can stimulate scientific thought, moving us further and further along the path of knowledge.
Today, the Gaia Hypothesis has become an impetus for the development of a modern version of the systemic organismic science of the Earth - geophysiology. Perhaps, over time, it will become the synthetic biosphere science that Vernadsky once dreamed of creating. Now it is on the way to becoming and transforming into a traditional, generally recognized field of knowledge.
It is no coincidence that the eminent British evolutionary biologist William Hamilton - the mentor of one of the most desperate critics of the theory, Richard Dawkins, and the author of the phrase "the selfish gene" used by the latter in the title of his book, called James Lovelock "Copernicus awaiting his Newton."