The question of induction has kept scientists busy since the dawn of science. If you see a white swan, and then another white swan, does this mean all swans are white? How can one establish a scientific claim basing on even a large number of observations? What if the millionth observation will result in a different outcome?
The black swan, discovered in Australia in the 17th century and announced the national bird in 1973, is a common metaphor in science, pointing at the weakness of the induction question. Many scientists tried to solve the black swan issue. One of them was Karl Popper, the most prominent science philosopher of the 20th century.
Popper came from a converted Viennese Jewish family. Attempting to solve the problem of induction, he suggested that instead of searching for a way to confirm a theory, there is no need to reject the assumption that the theory is true unless evidence that refutes it appears. According to popper, a scientific claim is true until it is refuted, not until it is confirmed. In other words, every scientific claim is temporary true.
Naturally, Popper’s revolutionary theory was not accepted overnight. Though most scientists like to think of themselves as some sort of Archimedes, freed from feelings, faiths, or prejudices, the truth is that they too can be blinded by hubris, or fixed on ideas, or terrified by new ones. One famous example is in the field we’ve all been affected by in the past year: molecular biology.
In 1958 Francis Crick the scientist who proposed the structure of DNA, set the central principal of molecular biology: that once information is transferred from nucleic acids (DNA or RNA) to proteins, it cannot flow back to nucleic acids. In other words, the final step in the flow of information from nucleic acids to proteins is irreversible. The genetic information is copied from the DNA into a molecule called RNA carrier, MRNA, a sort of translator of the genetic substance. After the MRNA leaves the cell’s core it gets to the cell’s proteins creators- ribosomes.
Crick’s theory, known as “the central dogma” matched most observations. Indeed in most cases the route from the DNA to the MRNA was in one direction. But then black swans began to appear in the system. Some experiments revealed viruses that contained only coded RNA genes that did not originated in DNA molecules. These viruses included for example the HIV virus.
Crick’s principle is referred to by the scientific establishment as “the central dogma” of molecular biology. Using the religious term “dogma” is more than just a metaphor. For over a decade, doubting Crick’s theory was as bad as heresy. Any researcher who dared to raise another conjecture, had to go through scientific Auto de fe ceremonies, where they were forced to repent in public or their career would be in danger.
Growing up with an orthodox father and an atheist mother, David Baltimore was indifferent to those kinds of semi religious bans. Baltimore was born in 1938 in New York, and was attracted to biology from a young age. With the support of his parents, he graduated in biology from Swarthmore College in Pennsylvania; then at the young age of 26 he graduated as a doctor from the Rockefeller University in New York. In 1972 he was appointed Professor of biology in MIT, and three years later, he won the Nobel Prize in medicine, when he was only 37 years old.
He shared the Nobel Prize with Renato Dulbecco, a catholic of Italian origin, and Howard Temin, born to a Jewish family in Pennsylvania (1934). Both Baltimore and Temin were Jewish and started their career in Swarthmore College; they also shared an intense interest in disobedient bacteria that did not obey to Crick’s dogma.
The two were not even aware to each other’s similar work. While Baltimore was in his lab in MIT, Temin was injecting rebellious viruses into mice in his lab in Wisconsin University. But in spite of the distance, they were both revolutionaries, as they discovered in the same time a mechanism that was to enact a revolution in the field of molecular biology and challenge Crick’s dogma.
Baltimore and Temin’s discovery, phrased for us laymen, is called reverse transcription ((RTase or RT). It overturned the dogma, that the information only flows in one direction, from the DNA to RNA. Those rare viruses were called retroviruses, as they were able to perform reverse transcription from RNA to DNA. After the retro virus enters the cells it relies on an enzyme to perform reverse transcription. IT IS considered one of the greatest discoveries in biology and in medicine in modern era, since it is a central process in common diseases such as AIDS and hepatitis B.
Though Covid19 that has been running our life lately, is not a retrovirus, it is in fact an RNA type, meaning its genome is made of RNA molecule rather than DNA like ours, and other animals’. In order to identify the virus, the Corona test, which is based on RT-PCR technology, uses the reverse transcription process, discovered by Baltimore and Temin. Furthermore, the discovery of the two Jewish researchers shed more light on the way the RNA molecule works – which is the protagonist of the newly invented Covid 19 vaccine by Pfizer and Moderna.
Baltimore and Temin suffered loads of contempt and skepticism when they first introduced their discovery to their peers. They were rejected by the establishment for years, as they were perceived as rebels against Crick, one of the field’s forefathers. But their insistence and courage proved they belonged to a special team of geniuses, like our acquaintance Popper, who dared to defy conventional thinking. Thanks to them, soon we will be able to “reverse transcript” our lives again, and return to pre Covid19 times. May we all enjoy good health. Now go, get yourself vaccinated!
