“Biochemical evolution of Oparin” - 2) Formation of biopolymers, lipids, hydrocarbons from accumulated organic compounds in the primary reservoirs of the Earth. The essence of the hypothesis was as follows... The origin of life on Earth is a long evolutionary process of the formation of living matter in the depths of nonliving matter. 1) Synthesis of initial organic compounds from inorganic substances under the conditions of the primary atmosphere of the primitive Earth. Oparin's theory. 1894-1980.

“The Oparin Hypothesis” - Biography. The hypothesis of the spontaneous origin of life. Hypothesis of biochemical evolution. The hypothesis of the origin of life on Earth by A.I. Oparin. Clots called coacervate droplets. Biography of A.I. Oparin. English biologist. Alexander Ivanovich Oparin. Concept. Living cell. The theory of the origin of life on Earth. Installation by Stanley Miller. Formation of the Earth's atmosphere. Stages of the emergence of life on Earth.

“Theories of biogenesis and abiogenesis” - Absence of living organisms. The theory of spontaneous generation. The rise of the classical doctrine of spontaneous generation. Theory of spontaneous generation. Worms. Stages of the emergence of life on Earth. Amino acids. Theory of biochemical evolution. Proponents of the theory of panspermia. Creationism. Theories of biogenesis and abiogenesis about the origin of living matter. Democritus English biochemist and geneticist John Haldane. Describe the biochemical stage of chemical evolution.

"Chemical Evolution" - Panspermia Hypothesis. Extraterrestrial origin of microorganisms. Spontaneous generation hypothesis. Geochronology. About 8 million are known. chemical compounds. The geological history of the Earth is inseparable from its biological evolution. Chemical evolution and biogenesis. Geochronological scale. Protostar - the Sun. The sun warmed the interior. Radioactivity. Russian chemist A.P. Rudenko. As the serial number increases, the prevalence of elements decreases.

"The Theory of Biochemical Evolution" - Life was created by a supernatural being. Formation of membrane structure. Hypothesis of biochemical evolution. A hypothesis that considers life as the result of long evolution. The third stage was characterized by separation. Concentration of substances in coacervate droplets. Molecules of many substances. Simple molecules. The first primitive living organisms. Long thread-like molecules. "Primordial Broth". One of the main characteristics of living things is the ability to replicate.

“Biochemical evolution hypothesis” - The process that led to the emergence of life on Earth. Origin of life on Earth. Primary broth. Miller, Stanley Lloyd. Oparin-Haldane theory. Miller-Urey experiment. Various aspects. Conditions for the origin of life. A. I. Oparin's hypothesis. Coacervate drops.

The molecules necessary for life could have arisen during chemical reactions at the dawn of the development of the Earth.

4.5 billion years ago, when the Earth arose, it was a hot, lifeless ball. Today, different forms of life are found in abundance on it. In this regard, the question arises: what changes have taken place on our planet from the moment of its formation to the present day, and most importantly, how did the molecules that form living organisms arise on the lifeless Earth? In 1953, an experiment was carried out at the University of Chicago that has now become a classic. He showed scientists the way to answer this fundamental question.

In 1953, Harold Urey was already a Nobel laureate, and Stanley Miller was just his graduate student. The idea of ​​Miller's experiment was simple: in a basement laboratory he reproduced the atmosphere ancient earth, what it was like according to scientists, and watched from the side what was happening. With the support of Yuri, he assembled a simple apparatus from a glass spherical flask and tubes, in which the evaporated substances circulated in a closed circuit, cooled and re-entered the flask. Miller filled the flask with gases that Urey and Russian biochemist Alexander Oparin (1894–1980) believed were present in the atmosphere at the dawn of the Earth's formation - water vapor, hydrogen, methane and ammonia. To simulate solar heat, Miller heated the flask on a Bunsen burner, and to get an analogue of lightning flashes, he inserted two electrodes into a glass tube. According to his plan, the material, evaporating from the flask, was supposed to enter the tube and be exposed to an electric spark discharge. After this, the material had to cool and return to the flask, where the whole cycle began again.

After two weeks of operation of the system, the liquid in the flask began to acquire a dark red-brown hue. Miller analyzed this liquid and discovered amino acids in it - the basic structural units of proteins. This gave scientists the opportunity to study the origins of life from the point of view of basic chemical processes. Since 1953, sophisticated versions of the Miller-Urey experiment, as it has since become known, have produced all kinds of biological molecules - including complex proteins essential for cellular metabolism and fatty molecules called lipids that form cell membranes. Apparently, the same result could be obtained by using other energy sources instead of electrical discharges - for example, heat and ultraviolet radiation. So there is little doubt that all the components necessary to assemble a cell could have been obtained in chemical reactions that took place on Earth in ancient times.

The value of the Miller-Urey experiment is that it showed that lightning flashes in the atmosphere of the ancient Earth over several hundred million years could have caused the formation of organic molecules that fell with rain into the “primordial soup” ( see also Evolution theory). Until now, unidentified chemical reactions occurring in this “broth” could lead to the formation of the first living cells. IN last years Serious questions arise about how these events unfolded, in particular the presence of ammonia in the atmosphere of the ancient Earth is called into question. In addition, several alternative scenarios have been proposed that could lead to the formation of the first cell, ranging from the enzymatic activity of the biochemical RNA molecule to simple chemical processes in the ocean depths. Some scientists even suggest that the origin of life has to do with the new science of complex adaptive systems and that it is possible that life is an unexpected property of matter that appears abruptly at a certain moment and is absent from its constituent parts. Nowadays, this area of ​​​​knowledge is experiencing a period of rapid development, various hypotheses appear and are tested in it. From this whirlpool of hypotheses should emerge a theory about how our most distant ancestors arose.

See also:

Stanley Lloyd Miller, b. 1930

American chemist. Born in Oakland, California, he was educated at the University of California at Berkeley and the University of Chicago. Since 1960 professional activity Miller was primarily associated with the University of California, San Diego, where he served as a professor of chemistry. For his work on the Miller-Urey experiment he was awarded the title research fellow at the California Institute of Technology.

Harold Clayton Urey, 1893-1981

American chemist. Born in Walkerton, Indiana, the son of a minister. He studied zoology at Montana State University and received a PhD in chemistry from the University of California, Berkeley. First used physical methods in chemistry and in 1934 was awarded Nobel Prize in chemistry for the discovery of deuterium, a heavy isotope of hydrogen. Later, his activities were mainly related to the study of differences in the rates of chemical reactions when using different isotopes.

ATTENTION!!! THIS MATERIAL HAS BEEN REVISED, ADDED AND INCLUDED IN THE BOOK “Creation or Evolution? How old is the Earth? TO READ GO TO PAGE -->

In the middle of the last century, University of Chicago scientist Stanley Miller tried in the laboratory to recreate the broth that, in his opinion, was on Earth before the origin of life on it. He mixed water vapor, ammonia, and methane in a flask and passed electricity through this medium. As a result, 3 types of amino acids were obtained out of 20, which are the constituent elements of protein (protein) of a living organism. Thus, the fact of the random origin of life was allegedly proven experimentally. However, this experiment has several significant drawbacks, which, although not advertised, are recognized by the supporters of evolution themselves: 1. ammonia could not have been on Earth in such quantities, since this gas is destroyed under the influence of ultraviolet radiation sun rays; 2. methane was not found in ancient sedimentary alumina; 3. The scientist immediately isolated the amino acids obtained during the experiment from further exposure to electrical discharges, since he knew that the current would again break the bonds obtained. But in nature, the thunderstorms that supposedly contributed to the creation of amino acids did not stop, which means they would always immediately destroy what they created; 4. The resulting amino acids, even theoretically, could not form any life, since as a result of the experiment, amino acids with a left and a right helix were obtained. But protein consists of a complex chain of left-handed amino acids, which are difficult to combine into one whole, but are easily broken. The presence of at least one amino acid with a right-handed helix destroys everything created previously; 5. oxygen was not taken into account, although today geologists find oxidized stones at great depths, which proves the constant presence of oxygen in the earth’s atmosphere. The oxygen present in that atmosphere would destroy the elements of the substance that the scientist received. Thus, the primary atmosphere in Miller's experiment was fictitious. After years of silence, Miller himself admitted that the environment he used in his experience was not real. Why did Miller insist on this gas mixture at one time? The answer is simple: without ammonia, amino acid synthesis is impossible.

Radiocarbon dating is wrong

The Earth's magnetic field is weakening

"Punctured" layers

Soil erosion at the initial level

The Moon is less than 10,000 years old

Population growth corresponds to the Biblical age of the earth

Moon close to Earth

Ice rings do not show years

The coral reef grew for less than 5,000 years

Dinosaurs are reliable witnesses

All people come from one pair

Civilizations and writing are less than 5,000 years old

The layers of the Earth do not have their own dating. Geological layers. Geochronological scale

Absence scientific evidence. Kent Hovind

The origin of life on Earth is one of the most exciting mysteries modern science. To the question Why this life eventually arose, it seems that astrophysicists will have to answer. Chemists can tell about the process of natural synthesis of the first simplest biogenic molecules.

It is worth saying that hypotheses about the first steps of life molecules on Earth appear regularly. Some concern self-organization processes, others make full use of rather contradictory natural evidence and so on. Meanwhile, the main weapon of a scientist since the time of Galileo remains experiment.

An experiment to recreate the earthly conditions that led to the synthesis of the first organic molecules, which ultimately became the building blocks of the universe, was carried out more than half a century ago. We were able to learn about some of its results only today.

Publication in the journal Science describes data that eluded scientists more than 50 years ago.

Then Nobel laureate Harold Urey, who received a prestigious prize for the discovery of heavy water and subsequently became interested in the problems of cosmochemistry, inspired one of his wards, Stanley Miller, with the theory of a prehistoric abiotic soup, from which, under the influence external factors The first organic molecules were produced.

A young employee at the University of Chicago, Stanley Miller, conducts his famous experiments on the synthesis of biological molecules. 1953 //Archives of the Department of Chemistry of the University of California at San Diego

According to the ideas of that time, the earth's atmosphere was very different from the present one. It contained a lot of methane and ammonia, water vapor and was almost completely devoid of oxygen, which facilitated the access of ultraviolet radiation from the Sun to the surface of the planet. In addition, volcanic activity was much more pronounced then, and thunderstorms accompanied by strong electrical discharges were not uncommon. Such conditions are ideally suited for many organic synthesis reactions, which prompted scientists to think about the biogenic future of such reactions.

In order to recreate such reactions in the laboratory under conditions similar to those that prevailed on Earth billions of years ago, Miller, then working at the University of Chicago, developed an original chemical device. It consists of a large reaction flask containing vapors of methane, ammonia and hydrogen, into which hot water vapor is pumped from below. On top are tungsten electrodes that generate a spark discharge. By simulating the conditions of a thunderstorm in the vicinity of an active coastal volcano in this way, Miller hoped to obtain biological molecules through synthesis.

After completing the synthesis, Miller was able to detect five amino acids in the reaction flask - the basic building blocks of all proteins: aspartic acid, glycine, alpha-aminobutyric acid and two optical isomers of alanine.

Two years later, Miller repeated his experiments in devices with a changed configuration. One of them involved the use of a jet pump with a nozzle that forcefully pushes saturated water vapor into the reaction flask. Thus, Miller hoped to make the experimental conditions as close as possible to the conditions of an underwater volcano eruption during a thunderstorm. The third apparatus produced a smoldering discharge instead of a spark discharge. The scientist was able to show the presence of several additional amino acids in the mixture of reaction products, and also demonstrated the presence of several additional carbonic and hydroxy acids.

However, in those years, Miller had to rely on analytical equipment that was very primitive by today's standards. Therefore, he and a group of colleagues repeated their experiments in 1972 using significantly more advanced equipment. True, then Miller carried out the synthesis in a device developed for publication in 1953, considering that devices with a nozzle and a glow discharge were not particularly productive.

Miller's device. Boiling water (1) creates a stream of steam, which is amplified by the aspirator nozzle (inset), a spark jumping between two electrodes (2) starts a set of chemical transformations, the refrigerator (3) cools the stream of water vapor containing reaction products that settle in a trap ( 4).// ​​Ned Shaw, Indiana University.

Stanley Miller died on May 20, 2007. While sorting through his diaries and archives, relatives and colleagues discovered notes related to the works of the 50s, as well as several bottles with signatures.

The signatures indicated that the contents of the flasks were nothing more than synthesis products in Miller's apparatus, preserved by the author in an inviolable form.

They became interested in Jeffrey Bada, a graduate of the Miller School of Chemistry, now also an old man working at the Institute of Oceanology at the University of California at San Diego.

According to Miller's notes, never before published, synthesis in an apparatus with a nozzle gave a slightly higher yield of products. It was these samples that interested Badu and his colleagues, the authors of the latest publication, who had the most advanced instrumental methods at their disposal.

In order to re-examine the composition of the synthesis products, the scientists dissolved the contents of the flasks in double-distilled deionized water and performed high-performance liquid chromatography, the results of which were analyzed on a mass spectrometer with a detector that recorded the flight time of ionized particles. This method of analysis makes it possible to identify the components of a mixture even in subpicomolar concentrations (less than 10 -12 moles per liter).

It turned out that the mixture of products did not contain five amino acids at all, but twenty-two! Plus five amine molecules that Miller simply could not identify half a century ago.

Having studied the remaining flasks using a similar method, the scientists became convinced that as a result of these experiments, the set of synthesis products was less diverse.

However, today geochemists claim that the Earth’s atmosphere has never been the same as it was thought to be 50 years ago. It was less basic and less restorative, so Miller's experiments cannot be relied upon as an experiment proving the abiotic soup theory. At the same time, the authors of the publication are confident that even if suitable conditions did not exist throughout the Earth, they undoubtedly should have accompanied at least spotty volcanic eruptions, the duration of which billions of years ago made it possible to join the synthesis of the first organic molecules and thunderstorms. These molecules could have collected in the lagoons of volcanic islands, where sea tides and solar ultraviolet light completed the condensation of aldehydes, ketones and other molecules into long polymer chains.

The popularity of the ancient abiotic soup theory in connection with Miller’s work allowed it to even be included in a school natural history course, but modern evidence suggests that life did not initially originate on the surface of the planet. The changing conditions here were too extreme even for life, which, against all odds, originated in small volcanic islands of stability, to spread and develop into modern forms.

True stability at that time existed only on the ocean floor, where in the zones of the mid-ocean ridges the heat of the Earth's interior slowly fed basic chemical reactions.

The mid-ocean ridges were discovered almost simultaneously with Miller’s experiments, and their detailed study is generally an achievement of the last ten to twenty years, which made research of the seabed accessible using deep-sea manned vehicles. If such devices appear before years by thirty - and the theory of abiotic soup might not have been put forward at all.

Repeat Miller's experiments under conditions more reminiscent modern ideas about the distant past of the Earth is yet to come. And it is possible that one of the current graduate students of chemical faculties is destined to become no less famous than Stanley Miller.

About why you may not like experiments, about the benefits of seminars, the nobility of a scientific supervisor and the emergence of a living thing in the background cold war We talk about it in our “History of Science” section.

Stanley Miller was born in 1930 into the family of a lawyer and a schoolteacher. Since childhood, the boy loved to read, studied well, loved nature, and went hiking with boy scouts. Following his brother, he entered the University of California, just like him, to study chemistry. Having easily passed the university course, he moved to the University of Chicago, which offered him a position as an assistant (after the death of his father, he could no longer afford to simply study). There began a long and difficult search for a topic for further work, a place where to apply my knowledge and bright mind.

Considering experiments to be “empty, time-consuming and not so important” (or maybe just expensive), Miller turned to theoretical problems. One of the professors whose work attracted Miller's attention was Edward Teller, who studied synthesis. chemical elements in the stars.

However, the Stanley Miller we are talking about today was “born” in the fall of 1951, when he began attending seminars with Professor Harold Urey, already a Nobel laureate at that time (for the discovery of deuterium). By that time, Yuri had become interested in cosmochemistry, the evolution of chemical elements in stars and planets, and made an assumption about the composition of the early atmosphere of the Earth. He believed that the synthesis of organic substances was possible in environments similar to ancient earth's atmosphere. These ideas fascinated Miller (so much so that he remembered the details of the lectures decades later), and he took his research to Urey.

Harold Urey

Wikimedia Commons

Thus, Miller took up a problem that attracted many scientists. William Harvey, Francesco Redi, Louis Pasteur, Lazzaro Spallanzani, Jacob Berzelius, Friedrich Wöhler argued about whether living things could arise from non-living things (and that’s not even everyone we’ve already written about in the History of Science).

The controversy did not subside in the 20th century. Our compatriot, Alexander Oparin, made a great contribution here. In the 1920s, he published an article “On the Origin of Life,” in which he outlined his theory of the origin of life from the “primordial soup.” Oparin suggested that the emergence of organic substances is possible in areas of increased concentration of high molecular weight compounds. When such zones acquired a shell that partially separated them from environment, they turned into coacervate drops - a key concept of the Oparin-Haldane theory (around the same time, similar ideas were developed British biologist John Haldane). Simple particles can form inside these droplets. organic matter, and after them complex compounds: proteins, amino acids. Absorbing substances from external environment, droplets can grow and divide.

However, let's return to Miller. His enthusiasm and desire to arrange some kind of experiment and test the theory did not find Yuri's sympathy at first: a graduate student should not venture into the unknown, it is better if he does something simpler. In the end, the professor relented, but gave Miller a year. There will be no results, the topic will have to be changed.

Miller got to work: he took Urey's data on the composition of the early atmosphere and suggested that the synthesis of compounds necessary for the emergence of life could be stimulated by an electrical discharge (it is believed that lightning was not uncommon on Earth in ancient times). The setup consisted of two flasks connected by glass tubes. There was liquid in the lower flask, and a mixture of gases in the upper flask: methane, ammonia and hydrogen - and steam. Electrodes were also connected to the top flask, creating an electrical discharge. In different places this system was heated and cooled, and the substance circulated continuously.

Miller-Urey Experiment

Wikimedia Commons

A week later, the experiment was stopped and the flask with the cooled liquid was removed. Miller found that 10-15% of the carbon was converted to organic form. Using paper chromatography, he noticed traces of glycine (they appeared on the second day of the experiment), alpha and beta aminopropionic acid, aspartic and alpha aminobutyric acids.

Miller showed Urey these modest-sounding, but so significant results (they proved the possibility of the emergence of organic matter in the conditions of the early Earth), and the scientists, although not without problems, published them in the journal Science. Only Miller was listed as the author, otherwise, Yuri feared, all the attention would go to him, the Nobel laureate, and not to the real author of the discovery.