An understanding of the nature of life is one of the most difficult and interesting mysteries for humanity. Over time, the mystery is inevitably gone beyond the question of whether there is life only on Earth or did she have somewhere else in the Universe. Is the emergence of life in a random and happy coincidence, or it is as natural to the Universe, as the universal laws of physics?
Scientists have been trying to answer these questions. One of them is Jeremy England, a biophysicist at the Massachusetts Institute of technology. In 2013, he led the hypothesis that the laws of physics could become a trigger of chemical reactions, simple substances allowed to organize in such a way that they ultimately acquired a “living” quality.
The results of the new work England and his colleagues noted that physics is naturally able to create processes samovosproizvoditsya reactions, which is one of the first steps to creating a “living” from “nonliving”. In other words, it means that life directly derives from the fundamental laws of nature that eliminates the possibility of the hypothesis of random occurrence. But that would be too loud a statement.
Life had to come from something. Biology has not always existed. She, too, was the result of a chain of certain chemical processes that led to the fact that the chemicals are somehow organized themselves into prebiotic compounds, created the “building blocks of life” and then turned into microbes, which eventually evolved into the amazing living creatures that exist on our planet today.
The theory of abiogenesis examines the emergence of life as emergence of living nature out of inanimate and England, the basis and key to non-living chemical compounds could turn into a live biological can be thermodynamics. However, as noted by the scientist himself, the latter study does not aim to create a connection between the “vital properties” of physical systems and biological processes.
“I would not say that I held a job that could answer the question of the very nature of life itself”, — said England in an interview with Live Science.
“What interested me is the very proof of principle – what are the physical requirements for the manifestation of the inanimate compounds of the living behavior.”
Self-organization in physical systems
When you use energy, the laws of physics dictate how this energy will be dissipated. If this system acted upon by an outside heat source, then the energy begins to dissipate until until around this system establishes thermal equilibrium. Put a hot Cup of coffee on the table and after a time the place where stood the Cup will be warm. However, some physical systems can be non-equilibrium, so using “self-organization” they are trying to make the most effective use of the energy of the external source, resulting in a run is pretty interesting, as pointed out by England, samomoderirovanie chemical reaction, preventing the attainment of thermodynamic equilibrium. It is as if the Cup of coffee spontaneously provoked chemical reaction, forced to support hot only a tiny coffee area in the center of the Cup, preventing it from cooling and transition to a state of thermodynamic equilibrium with the table. Scientists call such a situation “adaptation to dissipation”, and this mechanism is precisely what gives the opinion of England nonliving physical systems living properties.
The key behaviors of life is the ability of reproducing itself or being (from a biological point of view) reproduction. This is the basis for all life: begins as a simple, and then reproduced, it becomes more and more complex, and then again reproduced, and this process repeats again and again. And it so happened that amorality also is a very effective way of heat dissipation and increase in entropy within the system.
In the study published July 18 in the journal Proceedings of the National Academy of Sciences (proceedings of the National Academy of Sciences) England and co-author Jordan Horowitz describe how to verify his hypothesis. They ran some computer simulations of a closed system (a system that is not exchanging heat or matter with its environment), containing a “soup” of 25 chemicals. Despite the fact that their system was very simple, it is this “broth” most likely when something could cover the surface of the ancient, lifeless Earth. So it turned out that if these chemical substances are together and they are also under the influence of heat from an external source (e.g., hydrothermal wells), then these substances will need some way to dissipate this heat under the second law of thermodynamics, which says that the heat has to dissipate and the entropy of the system at this point will inevitably increase.
When certain initial conditions, scientists have discovered that these chemical substances can optimise the impacts on the energy system through self-organization and the subsequent active reactions for self-replication. These chemicals naturally self-adjust to the changed conditions. You create them the same reaction also produces heat, which corresponds to the second law of thermodynamics. The entropy of the system always will increase and chemicals will also continue to organize themselves and to show the vital behavior in the form of self-reproduction.
“In fact, the system first tries many solutions to small scale and when one of them starts to show a positive result, the organization has the entire system and adapts this solution does not take much time”, — said England in an interview with Live Science.
A simple model of biology as follows: molecular energy is burned in the cells, which by their nature are out of equilibrium and control the metabolic processes that support life. But as pointed out by England, discovered between vital properties and behavior in a virtual chemical soup and life itself there is a big difference.
Agrees Sara Imari Walker, a theoretical physicist and astrobiologist at Arizona state University who did not participate in the discussed studies.
“There are two ways to pass to try to unite biology and physics. One is understanding how you can get the quality of life from the simple physical systems. The second is to understand how physics is able to produce life. It is necessary to solve both of these conditions, to really understand what properties are really unique for life itself, and what properties and characteristics are typical things you can take for living systems, for example, prebiotics,” commented Imari Walker Live Science.
The origin of life beyond Earth
Before we begin to answer the big question of whether these simple physical system affect the emergence of life elsewhere in the Universe, you first need to better understand how and where such systems can exist on Earth.
“If the word “life” you mean something that is the same impressive as, say, bacteria or any other form with polymerases (proteins connecting DNA and RNA) and DNA, my job is not talking about how can be easy or hard to create something so complex, so I wouldn’t want to try to speculate if we can find something similar anywhere else in the Universe besides Earth,” says England.
This study does not determine how biology arose from non-biological systems, it only aims to explain some complex chemical processes, which occurs due to the self-organization of chemicals. Conducted computer simulations do not take into account other vital properties, such as adaptation to the environment or reaction to external stimuli. In addition, this thermodynamic study of a closed system does not take into account the role of transfer of the accumulated information, said Michael Lessing, a physicist and statistician working in quantitative biology at the University of Cologne.
“This work definitely shows the amazing result of the interaction of non-equilibrium chemical network, but we are still far from when physics can explain the nature of life, in which one of the key roles assigned to the reproduction and transfer of information”, — commented on Lessing Live Science.
The role of information and its transfer in living systems is very important, agrees Imari Walker. In her opinion, the presence of natural self-organization is present in the “soup” of chemicals doesn’t have to mean that it is a living organization.
“I believe that there are many intermediate steps which must be traversed to move from a simple order to a fully functional information architecture as living cells that requires the presence of something like a memory or heredity. We are of course unable to order in physics and nonequilibrium systems, but that does not mean that the way we get life,” said Imari Walker.
Experts generally believe that to say that the England job is “convincing evidence” of the nature of life is likely to be premature, as there are many other hypotheses that attempt to describe how life could have formed from nothing. But it definitely is a fresh perspective on how physical systems can self-organize in nature. Now that scientists have a General idea of how it behaves this thermodynamic system, perhaps the next step will be to attempt to determine a sufficient number of non-equilibrium physical systems that appear on Earth, says England.
Life: a coincidence or a law of physics…?
Nikolai Khizhnyak