The modern reader can be a supporter of any theory of the origin of life on Earth - from the theory of space drift to the eternity of civilizations. But a thinking reader should know that most scientists adhere to the presence of a prebiological period in the formation of life forms - abiogenesis. And the main theoretical base in this matter is the Oparin-Haldane theory or the theory of coacervate drops. What are coacervates and what are the theses of the theory of abiogenesis in the evolution of all living things - in this article.
The emergence of the term
The substantiation of the theory of coacervates belongs to the Russian scientist of the beginning of the 20th century A.I. Oparin. In 1924, he published his work on the results of the study of solutions saturated with high molecular weight compounds. He proved that stable zones of elevated concentrations of these substances are formed in them, which are called coacervates in biology. What is coacervate drops is a molecule of high molecular weight substance (protein), around which “shirts” are formed from water and low molecular weight compounds.
The Oparin-Haldane Theory
This process is called coacervation. What are the coacervates and Oparin ’s theory supported in 1929 by the Englishman J. Haldane, and it was their names that entered the name of the prebiological or chemical period of the origin of life on the planet. The theory suggests the spontaneous generation of high molecular weight organic substances during the early formation of the atmosphere and lithosphere of our planet.
Primary broth experiment
In 1953, chemists Stanley Miller and Harold K Yuri decided to put the experiment in an environment close in composition and conditions to the prebiotic on Earth. They placed a mixture of methane, ammonia, hydrogen in a flask and added water. By passing current through the solution (up to 60 thousand V), pumping pressure and raising the temperature to 80 degrees Celsius, they obtained a number of amino acids, urea, and other organic compounds. And in 1954, in India, the chemist K. Bahadur received organic matter under the influence of sunlight. About the theory of prebiological evolution and what is koatservata learned and spoke the whole world.
Gelatin in a glass
What is coacervate is easy to illustrate by mixing gelatin, gum arabic or albumin and water. Initially, clear solutions will initially become cloudy, and then small clots will appear in them, floating in the solution. These are the original coacervates. What can such compounds do? Separated particles can adsorb various substances and have a clearly structured structure, which determines their individuality. In the process of chemical evolution , selection was made for more stable forms, which became the basis for the emergence of living forms.
From coacervate to unicellular
In the primary ocean in prehistoric times, the first particles partially separated from the environment appear. They exchange substances with the environment (the prototype of a more complex metabolism), quickly disintegrate or maintain their integrity for some time. Drops grow (increase in size) and divide. And now a structure of a higher order is already appearing - the smallest lumps of living, which are inherent in the processes of synthesis and decay, development, growth and reproduction. From that moment, life began on planet Earth.
The problem of coacervate theory
All of the above is beautiful in theory. But, despite the successes of biologists in its confirmation, everything that we created today in primary broths is far from real life and the structure of the cell. And even the “protocell” created in 2008 by American biologists and the Japanese vesicle with a shell capable of sharing (2011) do not prove that this was exactly the case many billions of years ago on our planet. All these experiments only provide food for hypothesizing the possible path of the abiotic period of the evolution of life.
Incredibility events
British mathematician Fred Hall has calculated the likelihood of an accidental occurrence of a living cell in a primary broth. We will only say that in his calculations he used the entire modern arsenal of computers. Under some ideal conditions, this probability will be 1/10 * 40,000. This is a negligible quantity, which reduces the probability of such an event to almost none.
Probabilities happen
Nobody has yet canceled the theory of relativity, and a few striking examples will help show how absolutely incredible from the point of view of a mathematician does happen. For example, if people lived for 100,000 years, then 100% (that is, without exception) would die in air crashes. But the real fact is that the probability of winning the Cool Million American lottery is calculated exactly and this is 1 in 5,200,000. And the American Valerie Wilson won the main prize in 2002 and 2006. Or another example - in Bulgaria in 2009 an investigation was conducted into the work of the 6 out of 41 lottery. And all because with a difference of four days in different runs dropped six identical numbers. The probability of such an event is 3.61 • 10 −14 . So the incredible happens on our planet.