Dear students, today we will describe in detail the open and heldening experiment. According to their theory, life evolved in the oceans during a period when the atmosphere was reducing. Containing hydrogen gas, water, ammonia, methane and carbon dioxide, what? No free oxygen was there. In the early decades of the 20th century, a Luxander oprain in 1924 and John Haldonin in 1929 before opens first book was translated into English. Independently, Suyassar Thad, if the primitive atmosphere was reducing, means as opposed to oxygen rich atmosphere and there was an appropriate supply of energy such as lightening or ultraviolet light, then a wide range of organic compounds might be synthesized. According Suyassar Thad, the organic compounds could have undergone a series of reactions leading to more and more complex molecules. He proposed that the molecules formed collide aggregates or coservates in an aqueous environment. The coservates were able to absorb and assimilate organic compounds from the environment in a way reminiscent of metabolism. They would have taken part in evolutionary processes, eventually leading to the first life forms. Haldonin's idea about the origin of life were very similar to oprints. Haldonin proposed that the primordia sea served as a vast chemical laboratory powered by solar energy. The atmosphere was oxygen free and the combination of carbon dioxide, ammonia and ultraviolet radiation gave rise to a host of organic compounds. The sea became a hot dilute soup containing large populations of organic monomers and polymers. Many inviscised that groups of monomers and polymers acquired lipid membranes and that further developments and eventually led to the forced living cells. Haldonin coined the term pre-avietic soup and this became a powerful symbol of opren Haldonin view of the origin of life. Now we will discuss another experiment that show our light on the pre-avietic environment to the journey of evolution. This is the Yuri and Miller experiment. In 1952, Herald Yuri tried to calculate the chemical constituents of the atmosphere of the early earth. He waste his calculations on the widely held view that the early atmosphere was reducing and concluded that the main constituents were methane, ammonia, hydrogen gas and water. He suggested that his student, Stanley Miller, should do an experiment attempting to synthesize organic compounds in such an atmosphere. Miller carried out an experiment in 1953 in which he passed a continuous part discharge at 60,000 volts through a flash containing the gases identified by Yuri along with water. Miller found that after a week, most of the ammonia and much of the methane had been consumed. The main gases products were carbon monoxide and nitrogen. In addition, there was an accumulation of dark material in the water. Few of the specific constituents of this could not be identified. What it was clear that the material included a large range of organic polymers. Analysis of the aqua solution showed that the following had also been synthesized. 25 amino acids, that is the main ones being glycine, alanine and aspartic acid. Several fatty acids, hydroxy acids and amide products. The Yuri Miller experiment was immediately recognized as an important breakthrough in the study of the reason of life. It was received as confirmation that several of the key molecules of life could have been synthesized on the primitive earth in the kind of conditions in which is by opine and healthy. These molecules would then have been able to take part in pre-vietic chemical processing leading to the origin of life. Since the Yuri Miller experiment, a great deal of effort has been spent investigating pro-vietic chemistry. It has become apparent that organizing simple molecule into assemblies capable of reproducing and evolving is a far greater task than was generally realized during the excitement that followed the experiment. In addition, the view that the early atmosphere was highly reducing one was challenged towards the end of the 20th century and is no longer the concise view. Although, the significance of specific details of the Miller Yuri for the origin of life may know we in question. It began the new scientific discipline of pre-vietic chemistry and has been enormously influential in the development of ideas about the origin of life. In similar experiments, others observed formation of sugars, nitrogen bases, pigments and fats. This is of meteorite content also reveals similar compounds indicating that similar process are occurring elsewhere in space. With this limited evidence, the first part of the conjecture story that is chemical evolution was more or less accepted. We have no idea about how the first self replicating metabolic capsules of life arose. These capsules reproduce their molecules perhaps. The first cellular form of life did not possibly originate till about 2000 million years ago. These were probably single cells. All life forms were in water environment only. This version of a bio-genesis that is the first form of life arose slowly through evolutionary process from non-living molecule is accepted by majority. However, once formed, how the full cellular form of life could have evolved into the complex biodiversity of today is the fascinating story that will be discussed in coming episodes. So my dear students, today we have discussed in detail the open and healthy experiments that told that the life evolved in the oceans during a period when the temperature was reducing. The similar experiment was also carried out by Yuri and Miller, which shows that the atmosphere during the origin of life was also reducing one. The molecule formed collide aggregates are coservates in an aqueous environment. The coservates were able to absorb and assimilate organic compounds. In the next episode, we will discuss about the evolution of human beings in detail. That is how do we have evolved from the different time periods. Thank you.