From penicillin to Viagra: when chance leads to impactful scientific discoveries

"There once was a king who had three young sons, in the country of Serendip. As his successor, the king wanted to appoint the son who was the smartest and most capable of solving the daily problems of his people"… As a story of Arabian Nights, thus begins the version of a Persian tale in which the three sharp and clever princes of Serendip (present-day Sri Lanka) describe, as if by divination, a stolen camel they have never seen before. In reality, they infer it from small clues that seem trivial to the rest of the audience, but which, by applying deductive reasoning, allow them to make inferences and describe the animal with a mental game. The tale, translated from Persian to Italian by a certain Cristoforo Armeno and published by an Italian editor, it was translated into French and reached England, so that in 1754 Horace Walpole coined a new word, "serendipity" in a letter he sent to a friend to explain the fortuitous way in which he made an interesting discovery.

Before the term serendipitousWe can find references to this idea in several scientists when they comment on the impact of chance – or results not directly sought – on their research. Albert Szent-Györgyi, discoverer of vitamin C and Nobel Prize winner in medicine in 1937, said that "to discover is to see what everyone sees but to think what no one has ever thought." Other researchers have also defined the state of discovery as "a stroke of fortune" (Robert Hooke), or that "invention is the fruit of intention, while discovery is the fruit of surprise" (Root-Berstein). The intervention of luck and chance in science, and the concept of serendipity, have been gaining recognition, and it is currently a broad term that indicates that the process of discovery in research is not always direct and linear, but that often, unintended results—we might even say serendipitous results—allow for scientific discoveries. Medicine, evidently, is no exception.

From penicillin to Viagra

The example you can find everywhere about Scientific serendipity is Alexander Fleming's discovery of penicillin –which earned him the Nobel Prize in 1945–, an antibacterial compound that the fungus Penicillium glaucum produces to compete for the same space as bacteria in a fight for survival. Natural selection has made it possible for fungi to produce bactericidal and bacteriostatic compounds (which kill or limit bacterial growth, respectively) to occupy the same ecological niche. Other scientists before Fleming had found similar data, but they did not feel challenged or did not pursue them. Fleming left some Petri dishes with bacteria on his laboratory bench, and when he returned a few days later, he discovered that fungi of the genus Penicillium had grown. However, in a nearby radius, bacteria had not been able to grow. It is known that upon seeing it he exclaimed: "How curious!" Certainly, he could have left it there, like other researchers until then, but this fortuitous result intrigued him so much that he investigated the phenomenon, until other people were able to extract his first antibiotic, which has made it possible to cure so many infections.

It is true that if Fleming had read all the existing bibliography he would have seen that Ernest Duchesne had already defended a doctoral thesis on the subject., decades earlier. But discoveries need an appropriate context to be successful and socially accepted. The health emergencies generated on the battlefield during World War II facilitated the implementation of antibiotics, which had just been isolated and produced in limited quantities, as the preferred treatment for war wound infections.

Now that we know how to define serendipity, there are many other medical discoveries that are the result of this stroke of luck, whether more or less targeted. We'll mention a few: the English physician Edward Jenner discovered in the late 18th century that women who milked cows never became infected with smallpox if they had previously contracted a milder cowpox infection. This led him to conduct a series of experiments and implement a preventative measure: infecting people with cowpox to protect them against human smallpox. This was the beginning of the vaccination, which brings us so many benefits in the immunization of children.

The discovery of the first anticoagulant, warfarin, very similar to Sintrom, occurred as a result of the Death of cows due to internal hemorrhages when eating sweet clover, a weed. The Great Depression in the United States during the 1920s led ranchers to feed their cows with field grasses, including melilot, a legume that contains coumarin, which is converted into dicoumarol by the fungi that infect it. Dicumarol is the basis of warfarin.

On the other hand, Viagra was initially developed as a treatment for angina pectoris, but it was quickly discovered that male patients had erections without stimulation when taking it, and this indication (as we all know) has far surpassed its use in cardiology. And now in the area of basic research that will totally revolutionize the biomedicine of the future, The CRISPR gene editing system was discovered by Francis Mojica, a microbiologist from Alicante who studied microorganisms capable of living in the salt flats of Santa Pola.

There are researchers who propose that the Artificial intelligence could open new avenues for "facilitating" serendipity. Sure, but we must consider the fact that AI works through algorithms that someone has programmed, with their biases, both positive and negative. All of this should make us reflect on whether serendipity in research in and for humans, and carried out by humans, is "unconsciously" directed or free and unpredictable. "Predictable" serendipity can very likely be accelerated by AI, but unpredictable (and therefore not directly programmable) serendipity cannot be replaced by AI. At least not for now.