There is no subject of such tremendous import for us as the question of how living, feeling, thinking creatures arose out of inorganic matter. This riddle has occupied the human mind from the earliest times, and has been answered in various ways. We can broadly identify three trends:

1st theory – God created all life, including humans.

2nd theory – life arose from inorganic matter, by spontaneous generation, as maggots from decaying flesh, or beetles from a dunghill (Aristotle).

3rd theory – life came from outer space in a meteorite, which fell on the earth, and then developed.

This transformation from inorganic to organic is a comparatively recent view. In contrast, the theory of spontaneous generation – that life originated from nothing – has a long history. From ancient Egypt, China, India and Babylon came the belief in spontaneous generation. It is contained in the writing of the ancient Greeks. “Here maggots arise from dung and rotting meat, here lice form themselves from human sweat, here fireflies are born from the sparks of a funeral pyre, and finally, frogs and mice originate from dew and damp earth”. As Oparin reported: “For them spontaneous generation was simply an obvious, empirically established fact the theoretical basis of which was of secondary importance”.[13]

Much of this was bound up with religious legends and myths. By contrast, the approach of the early Greek philosophers was materialist in character.

It was the idealist view of Plato (expressed also by Aristotle), which invested spontaneous generation with a supernatural quality and later formed the basis of mediaeval scientific culture and dominated people’s minds for centuries. Matter does not contain life but is infused with it. Through Greek and Roman philosophical schools, it was borrowed and elaborated by the early Christian church to develop their mystical conception of the origin of life. St. Augustine saw in spontaneous generation a manifestation of divine will – the animation of inert matter by the “life-creating spirit.” As Lenin points out, the scholastics and clerics seized upon that which was dead in Aristotle and not upon that which was alive. It was later developed by Thomas Aquinas in accordance with the teachings of the Catholic Church. A similar standpoint is held by the Eastern churches. The Bishop of Rostov, Dimitrii, in 1708 explained that Noah did not take in his ark those animals capable of spontaneous generation: “These all perished in the Flood and after the Flood they arose anew from such beginnings.” This was the dominant belief in Western society up until the mid-19th century.

The great Thomas Henry Huxley in his Edinburgh lecture in 1868 first clearly explained that life had one common physical basis: protoplasm. He stressed it was functionally, formally and substantially the same over the whole range of living things. In function, all organisms reveal movement, growth, metabolism and reproduction. In their form they are composed of nucleated cells; and in substance, they are all made up of proteins, a chemical compound of carbon, hydrogen, oxygen and nitrogen. This graphically reveals the underlying unity of life.

The French scientist Louis Pasteur, the father of microbiology, in a series of experiments finally discredited the theory of spontaneous generation. “Life could only come from life,” said Pasteur. The discoveries of Pasteur dealt a crushing blow to the orthodox conception of spontaneous generation. The further triumph of Darwin’s theory of evolution forced the vitalists (the idea of the “life force”) to look at the origin of life in a new way. From now on their defence of idealism came in the argument of the impossibility of understanding this phenomenon on the basis of materialism.

As early as 1907, in a book called Worlds in the Making, the Swedish chemist Svante Arrhenius put forward the theory of panspermia, which concluded that if life could not occur spontaneously on the earth, then it must have been introduced from other planets. He described spores travelling through space to “seed” life in other planets. Any life spores entering our atmosphere, as with meteorites, would burn up. To counter these criticisms, Arrhenius argued that life was therefore eternal, and had no origin. But the evidence contradicted his theory. It was shown that the existence of ultraviolet rays in space would quickly destroy any bacterial spores. For example, microorganisms selected for their toughness, were put on the space capsule Gemini 9 in 1966, and exposed to radiation from space. They lasted six hours. More recently, Fred Hoyle thought that life had been brought to earth in the tails of comets. This idea has been revamped by Francis Crick and Leslie Orgel who suggested that earth might have been deliberately seeded by intelligent life from outer space! But such theories really solve nothing. Even if we accept that life came to earth from another planet, that still does not answer the question of how life arises, but merely puts it back another stage – to the hypothetical planet of origin.

It is not necessary to travel to outer space for a rational explanation of the origins of life. The origins of life can be found in the processes at work in nature on our own planet over three and a half billion years ago, under very special conditions. This process can no longer be repeated, because any such organisms would be at the mercy of existing life forms which would make short work of them. It could only arise on a planet where no life existed, and also when there was little oxygen, since oxygen would combine with the chemicals needed to form life and break them down. The earth’s atmosphere at that time was mainly made up of methane, ammonia and water vapour. Experiments in laboratories have shown that a mixture of water, ammonia, methane and hydrogen, subject to ultraviolet radiation produced two simple amino acids, and traces of more complicated ones. In the late 1960s, complex molecules were found to be present in gas clouds in space. It is therefore possible that, even at a very early stage in the earth’s formation, the elements for the emergence of life, or near-life, were already present in the form of amino acids. More recent experiments have proven beyond all doubt that the proteins and nucleic acids, which are the basis of all life, could have emerged from the normal chemical and physical changes taking place in the primordial “soup”.

According to Bernal, the unity of life is part of the history of life and, consequently, is involved in its origin. All biological phenomena are born, develop and die in accordance with physical laws. Biochemistry has demonstrated that all life on earth was the same at a chemical level. Despite the enormous variation between species, the basic mechanism of enzymes, coenzymes, and nucleic acids appear everywhere. At the same time, it forms a set of identical particles that hold themselves together by the principles of self-assembly in the most elaborate structures.

  1. Oparin, A. op. cit., p. 2.