In Greek mythology Prometheus stole fire from the gods (“fire” as a metaphor for “knowledge”) and delivered it to men, thus launching humanity’s progress. In the novel published 200 years ago by Mary Shelly she saw Victor Frankenstein as the New Prometheus. He “robs” nature of its great secret, the electrical discharges from storms that are capable of breathing life into inanimate matter.
What has happened since then with the use of electricity for this purpose? Of course, it has not been possible to “create life” using inanimate matter, or to revive dead human beings with electrical impulses (the most that we have managed is to revive heart-attack victims using heart defibrillators). But there have been experiments, including some very important recent ones, that indicate electricity could have played a very important role as the spark that “awakened” the key molecular components of living beings, through very simple chemical materials.
Electricity in Mary Shelley’s time
When Mary Shelley published her novel Frankenstein in 1818, at a time of a great revolution from which emerged a number of inventions that would change society, including the steam engine, the guillotine, and various forms of batteries.
In the field of biology, in 1770 Luigi Galvani discovered that the application of electrical discharges to the spinal cord of dead frogs produced a contraction and movement of their muscles and membranes as if they were alive.
The author of Frankenstein was an exceptional woman in the masculine world of the time. She had been educated in a free-thinking and scientific family, and had even experimented in Oxford with ideas and devices related to electricity. So it’s no surprise that her work of fiction uses electricity as the force that returns dead matter to life.
Since then, and until mid-way into the 20th century, the possibility that electricity could have played a role in the origins of life remained within the realm of speculation. For example, on February 1, 1871, Charles Darwin wrote a letter to his friend John Hooker in which he speculates on the forces that could be involved in the origins of life and mentions “light, heat and electricity.”
The key experiment
Everything changed in 1953, an auspicious year for Biology, as it was the year when Watson and Crick proposed their model of the double helix of DNA; and it was the year when the results of an experiment were published confirming the possibility that electricity could act as the “spark” that “ignited” life at molecular level.
Specifically, in 1953 the Nobel Prize Winner Harold Urey and his student Stanley Miller demonstrated that in a closed and sterile glass circuit containing only water and a mixture of gases (hydrogen, methane and ammonia) of the type that could have been present in the primordial atmosphere, if the water was heated and subjected to electrical discharges, the result was one of the two fundamental components of living beings: amino acids (1), which form the proteins that are act on the structures and functions of living beings.
This experiment constituted the starting point of what would be called Prebiotic Chemistry, in which a great number of experiments have been carried out in an attempt to obtain the different molecular components of living beings through abiotic means. But these experiments in using electricity as a source of energy came up against a difficulty in terms of how this force of nature could play a wide-ranging and general role in the origin of the key elements for living beings. This is because in no case was it possible to synthesize nucleotides, another important molecular component of living beings, which form the nucleic acids that allow organisms to pass on their characteristics from generation to generation. But recently this changed.
Electricity can also produce nucleotides
Until the end of the 1950s no one had been able to obtain in prebiotic conditions any of the nitrogenous bases (adenine thymine, cytosine and guanine) that form the building blocks of nucleic acids. However, at the end of 1959 the Spaniard Joan Oró was able to produce adenine, and later together with Miller was capable of doing the same for guanine. In no case, though, was electricity used in the experiments as a trigger for these nucleotides.
That is what has been achieved recently in an experiment (2) using a reductive atmosphere similar to that of the Miller-Urey experiment and three simple chemical components (ammonium, carbon monoxide and water), combined with electrical discharges to synthesize the four nitrogenous bases. But the curious point is that these 4 bases are not those that form DNA, but RNA (three of these ribonucleic bases, adenine, guanine and cytosine are the same as in DNA, except that they carry one more OH group; but the fourth is uracil (which is simply the thymine of DNA with the OH group and without a CH3 group). This also supports the idea that RNA could have originated before DNA itself.
Currently we have experimental data indicating that electricity, together with other forces such as radiation (above all ultraviolet), and heat, could act as a force triggering the origin of the molecules that are key for life: the amino acids and nucleotides. These could constitute the first molecular steps on the long Frankensteinian journey of Life’s awakening, as just like Frankenstein’s monster, life is made up of many parts and steps. The following steps, the formation of large macromolecules such as proteins and the two types of nucleic acids, the “hook” for the three macromolecules, and the construction of cellular membranes and structures, constitute a long history, still full of gaps and unknowns. We can only hope that the adventure of Life on Earth does not end so badly or so quickly as the life of Frankenstein’s creature, and that with time we can understand all the pieces of this history.
- Miller, S.L. 1953. A production of amino acids under possible primitive Earth conditions. Science. 117:528-529. Although the article was signed only by Miller, its co-author was the Nobel Prize Winner Urey, who wanted to give all the credit for this find to his student.
- Ferus, et al., 2017. Formation of nucleotides in a Miller-Urey reducing atmosphere. PNAS, Apr. 25, 114(17):4306-4311.