Can a planet be alive? It is believed that Lynn Margulis, a distinguished biologist of the late 20th century, the owner of a brilliant intelligence and supporter of the unconventional approach. Along with chemist James Lavloka she viewed life as a planet-changing phenomenon, and the distinction between “alive” and “inanimate” beings considered not as pronounced as one might think. Many members of the scientific community ridiculed their theory, called the Gaia theory as pseudoscientific, and questioned their reputation. But now Margulis and Lovelock can take revenge. Recent scientific discoveries give reason to get serious about their hypothesis. It is based on the idea of the connection between planets and living organisms that changed our understanding of both of these concepts and shapes our understanding of other worlds.
By studying together the biosphere of the Earth, Margulis and Lovelock came to the conclusion that she has some peculiar to living beings properties. This, apparently, refers to “homeostasis”, that is, self-control. Many of the abilities of our planet to support life are surprisingly resilient. The range of climatic temperatures, the oxygen content in the atmosphere, as well as the acidity, chemical composition and degree of salinity of the ocean is biologically mediated and the habitable range, despite the past hundreds of millions of years. Margulis and Lovelock suggested that the totality of living organisms in close interaction with the environment through the regulation of these global characteristics. They recognized the fact that the Earth is in some sense a living organism. Lovelock called this the “Gay phenomenon”.
Earth and life evolved and continue to evolve together.
Margulis and Lovelock showed insufficient validity of the pattern of biological evolution of Darwin. Darwin, defining the mechanism by which living organisms adapt to environmental changes, gave us to understand that life on Earth is a continuous process, growth and reproduction, as well as the transfer of genes inherited from the common root. From the perspective of Darwin, the Earth was a kind of scene-changing scenery, which had to adapt to life. But who will change the scenery? Or what? Margulis and Lovelock suggested that the Earth is not dead, but animated is part of a larger entity, consisting of the biosphere and “inanimate” matter, which shape the biota of the Earth, responsible for it and pass through it in a loop. Yes, life adapts to changes in the environment formed by natural selection, but it’s also opposed by the environment, changing it, and the planet itself. Now it is as plain as filled with oxygen in the air we breathe. Thus, evolution is not a series of attempts to adapt to inanimate events, and system response and exchange. Life is not just aligned to the dynamically changing face of the planet. Most likely, was mutual formation of living organisms and the Earth in the process of their joint evolution. If you look at the planet from this point of view, you will see that all the coral reefs, limestone cliffs, river estuaries, marshes and Islands cave guano — is part of the larger living entity. You will realize that the surface and the bowels of the Earth live.
The hypothesis of Gays in the past and now are very wary and not completely. There are a number of reasons. One of them is the usual inertia, standard conservative reluctance to embrace a new way of thinking. In addition, the theory was considered vague and uncertain. Some complained about the inability of its adherents to present a remarkable, grounded, experimentally testable judgment. As you can appreciate, to oppose or to accept the idea in which there is no clear understanding or that different people perceive in different ways? This definitely has some truth. The Gaia theory was formulated in various ways. Not helped by the fact that Margulis and Lovelock tried to mix science with philosophy and poetry and didn’t mind the contradictions; I’d say they liked it.
The truth is that despite such a common name, the principle is Gay — not exactly a hypothesis. A perspective, approach, in which scientific research about life on the planet —the planet is alive, and not just the one on which there is life — that’s the main idea, simple but deep. Because life is not a minor detail that emerged in an already functioning planet Earth, but an integral part of its evolution and characteristics. Over the past few decades, proponents of the theory of Gaia has almost achieved victory. In fact, the opposition never gave up and did not recognize his defeat, but accepted the science of the Earth has lost its position and has joined forces with chemistry, climatology, theoretical biology and some other fields of knowledge, and renamed themselves “the science of the Earth system”.
Approach Gay, provoked a space comparison of the Earth with her supposedly lifeless neighbours, has led to a deeper understanding of how much our planet has changed under the influence of its inhabitants. Comparing the history of life of Earth with its counterparts, we see that in the very early stages of its development, the Earth began to evolve in a different way. From this moment on the planet and living organisms began their joint development.
Studying the Earth using modern tools, seeing it as a whole from a distance, drill wells on the ocean floor and showing the global biochemical cycles of elements, nutrients, and energy through “magic glasses” generating multi-spectral images, we found that the effect of life on the planet is more complex and comprehensive than we could imagine.
The oxygen that we take for granted is a by-product of organisms intervening in the geochemical cycles of the planet: the collection of solar energy for splitting water molecules, storing the hydrogen atoms and their reaction with CO2 for the production of organic food. In the upper layers of Earth’s atmosphere a part of this oxygen under ultraviolet light is converted to the ozone layer, which serves to shield the planet from harmful UV rays, making its surface habitable. The emergence of this protective layer was followed by the exit of life from the ocean and the emergence of forests on the continents. This made the once lifeless continents suitable for existence of living organisms.
The more we look through the prism of the theory of Gaia, the more we realize that almost every component of our planet were biologically distorted beyond recognition. The rocks of the Earth contain more than 4,000 different minerals (crystalline molecules that make up rocks). This diversity of types of minerals more than have so far been discovered on other planets. Geochemists studying the history of minerals of the Earth, came to the conclusion that most species could not exist without the presence of life on our planet. Thus, changing the Earth’s surface living organisms, and the mineral rocks are a by-product of their activity. A big leap in their diversity occurred after the organisms filled the atmosphere with oxygen, which led to the abundance of oxidized minerals that have stained the sediments across the surface of the Earth in bright colors. On some distant planet is such a vast and colorful variety of minerals could mean the presence of life on it, which is a potential biopores that we can add to the designated Lavloka basis knocked off balance by living organisms of atmospheric gases. Thus, minerals and living organisms fed off each other from the beginning. There was still more evidence that the minerals were essential catalysts and substrates of the origin of life on Earth. But is it really a reason to consider mineral the Earth’s surface as part of the global living system?
What about plate tectonics and the dynamics of Earth’s interior? At first glance it’s like a giant mechanical system is a heat engine which does not depend on biology, but, fortunately for life, supports it. In addition, although we and not fully aware of the deep elements of the Earth’s biosphere, the probability that living organisms exist at depths greater than a couple of miles, quite low due to extremely high and therefore unacceptable for organic molecules temperatures. However, we know that life reached the upper layers of earth’s atmosphere and created ozone layer, which allowed the biosphere to cover the continent, and now observe its impact on the deep underground areas. Throughout his long life, the superorganism of Gaia had an impact not only on the surface itself, but also on the processes inside the planet, removing hydrocarbons from the mantle and leaving it on the surface in sedimentary rocks, as well as sequestering a huge amount of nitrogen from the air into ammonia deposited in crystals mineral rocks of the mantle.
Life itself is only just starting, can make and / or keep the planet habitable. By controlling the chemical state of the atmosphere, life has also changed breed, entering it into contact with oxygen saturating earth’s crust and mantle. This has changed the material properties of rocks, how they bend and break, collapse, bend, and melt when exposed to various forces and conditions. All clay minerals produced by the terrestrial biosphere, has softened its bark (bark of a lifeless planet harder), helping to lubricate the engine of tectonic plates. The moisture content of the Earth explains why plate tectonics is preserved here, and not on a dry Venus. One of the most extreme statements of adherents of the theory of Gaia, currently neither proved nor disproved, is, that for billions of years the impact of life helps the Earth to retain vital moisture, while as lifeless most of its existence, Venus and Mars its lost. In this case, the presence of life can indeed be responsible for plate tectonics of the Earth. One of the founders of the theory of plate tectonics Standards Slip from Stanford fully convinced that life is deeply involved in General physical dynamics of the Earth, including “inanimate”. In the description of the cumulative long-term effects on Geology, the building of continents and plate tectonics, he wrote that “the end result is the principle of Gaia. That is, life has altered the Earth in their favor.” The more we study the planet, the more we see it. Life keeps the Earth stranglehold. Earth is a planet of biologically modeled to the bone. In other words, alive.
Now, 40 years after Viking landed on Mars, we learned that the planets have a common origin, including similar in size to Earth and acceptable to the presence of oceans of liquid water, distance from its star. In addition, Lovelock’s radical idea to pay attention to the atmosphere and to seek drastic deviation from the usual mixture of gases is currently the cornerstone of our strategy for the discovery of life on other planets. The thinking of the adherents of the theory of Gaia has crept into our understanding of the evolution and habitability of exoplanets, forcing us to reconsider the concept of “habitable zones”. We understand that it is impossible to draw conclusions about the suitability of the planet for the development of life on it only on the basis of its basic physical characteristics, size and distance from its star. Life itself is only just starting, can make and / or keep the planet habitable. Perhaps in some cases life may destroy the habitability of the planet, as it almost did on Earth during the “great oxygenation” (sometimes called the oxygen catastrophe) 2.1 billion years ago. Once my colleague said Colin Goldblatt, a sharp young developer of climate models at the University of Victoria, “the defining characteristic of Earth is the life on a planetary scale. The earth teaches us that the habitability and the presence of life are inseparable”.
In his book “Lonely planet” (2003), I described what is called “living worlds hypothesis”, based on the principle of Gaia in relation to astrobiology. Life is probably a planetary-scale phenomenon with a cosmological life cycle — in other words, life expectancy is measured in billions of years, that is, the same time frame that determine the life of the planets, stars and the Universe itself.
Of organisms and types of cosmological life cycles there, and the phenomenon of Gays there, and this, perhaps, is the common property of living worlds. Being under the influence of beliefs Lovelock and Margulis, I argued that we are unlikely to find life on the surface of the planet with a normal atmosphere. According to this idea, the planet can’t be “almost alive” (how not may man, at least for a long time), so these old planets like Mars in the absence of obvious life is probably quite dead. If a small methane emissions, recorded recently by the Mars Rover “Curiosity”, will appear the signs of the islets of Martian life on the planet is considered dead, it will refute my hypothesis of “living worlds” and the possibility of life in forms different from the beliefs of the adherents of the theory of Gaia. But the living world may need more than only a small temporary pools of water and energy, which, of course, exist beneath the surface of Mars. He may have been coming from inside the continuous geological activity. I believe that only in a geological sense, a “live” planet is “alive” in biological. Life on Mars may never have been able to establish itself as a permanent feature without the presence of plate tectonics, as well as such a deep and powerful global biogeochemical cycles as on Earth.
As far as we can tell, around the time when life originated on Earth, Mars and Venus had similar characteristics to start the process of the origin of life: both had water, rocky surface, a dense atmosphere and active geological activity. Comparative planetology tells us that the conditions necessary for the emergence of life may be the norm for rocky planets. There is a real chance that Mars or Venus life also occurred, but are unable to take root and become an integral permanent feature of planets, as happened on Earth. You can combine them as planets on which life emerged, but which are unable to create a reliable and self-sufficient biosphere. Speaking of Land, a really rare and unusual is the fact that favorable conditions for life have been preserved for billions of years. Maybe it was more than luck.
If you think about the planets not as the objects or places may or may not be living beings, as living or nonliving entities, you can change the view on the origin of life. Perhaps life is something that is not ON the planet, With the planet: that’s what planet earth is becoming.
Think about life from the point of view of fire. If you have ever tried to build a fire, know that light a spark and get a flame easily, and save hard. First you need to dizziness to blow on a fire to supply it with oxygen, or it just goes out. Not to let the fire go out, while he hardly breaks out, the task is always difficult. Then it reaches a critical point, and the fire begins to rage. Thanks to the hot coals, the heat maintains its own circulation, sucking the oxygen fanning the flame. Now, when the fire became self-sufficient, you can go to drink beer and watch for shooting stars.
I wonder if the first life on the planet on the first sparks and the shifting lights fanning the flames? At the earliest stages of life can be extremely vulnerable, and there may come a time when, becoming a planetary phenomenon and becoming a part of the global flows that support and feed her, she will act in the opposite direction like a self-sustaining fire, which not only provides a flow of air, but also replenishes the fuel supply. Mature biosphere, it seems, creates the conditions for the preservation and prosperity of life.
Life is what happens not ON the planet, and the planet.
The prospect of “living worlds” implies that through billions of years of life or disappear from the planet entirely, or, as on the Earth, thoroughly take root and become an integral part of all global processes. The signs of life are present everywhere. Once on the planet and becoming a phenomenon on a planetary scale (the global body if you wish), to destroy it can be very difficult. Of course, the Earth has undergone many changes, some of which were quite traumatic. Life on our planet is unusually stable and continuous, and sometimes it seems even immortal. Call it quasi-immortality, because always planet will not exist, as well as may not maintain its habitability. The presence of people — only a moment. Appear and disappear whole species, and timing of their existence, as a rule, hardly enough to attract the attention of the world. And yet, in the complex life saved. This creates a new perspective on ourselves. The scientific revolution showed us, as individuals, what we are incredibly tiny and ephemeral, and that our existence not only as individuals but as a species is brief and minor in the temporary context of cosmic evolution. If, however, we will identify ourselves with the biosphere, as part of the superorganism we were here for maybe three billion years of those thirteen, which was considered the universe exists, that is, a quarter of the time. And this is something.
The origin of life on Earth was not only the beginning of species evolution and storehouse of diversity, through which bloomed algae, appeared in the aspen groves, barrier reefs, rookeries of walruses and gorillas. From the point of view of planetary evolution, this development has become a major site of branching, which opened the door to a fundamentally different future. But when life has spread and deepened, the planet Earth and her sister went separate ways.
And recently, this biologically altered Earth suddenly there are new changes that began to rewrite the rules of planetary evolution. On the unlit side of the Earth the light turns on, indicating the emergence of something new, and it’s already here. Can, opened another door? Whether the planet is in a new branch point?
View from space sheds light on the many rapid changes are inscribed in our industrial society in the history of the planet. Orbital technologies, providing conditions for such observations are themselves one of the strange and startling aspects of the rebirth of the Earth. If still its defining characteristic was the widespread life, what about the lighting on the planet. Can this vast light network become part of a new defining characteristic?
David Grinspoon is a senior researcher of the Institute of planetology and member of teams working on several active and future interplanetary flights. In 2013 was appointed to the chair of astrobiology at the Library of Congress. His latest book “Earth in the hands of man” appeared on the shelves in December. Musician, guitarist of the band “House Band of the Universe”.