Gregor Mendel’s story shows why science should not be driven by ideology

July 20, 2022 marks the bicentenary of the birth of revolutionary scientist Gregor Johann Mendel. He suggested that information about ‘traits’ is passed down from one generation to the next as particulate ‘elements’ and that traits in the current generation can be traced back to previous generations. The idea was revolutionary because there was no theory about the mechanism of inheritance before Mendel. Mendel’s theory, along with the evolutionary theory put forward by Charles Darwin, laid the foundations of biology.

Mendel completed his education from a gymnasium in Troupo. The physics teacher in the gymnasium, Friedrich Franz, who was impressed by his talents in physics and the natural sciences, presented him with a life-changing proposal. Franz, the priest, told Mendel that the Augustinian Order of the Catholic Church values ​​intellectual pursuits. He suggested that the priesthood could offer Johan a path of learning and education. Johann took hold of the proposal and joined the abbey of St. Thomas in Brunn (now Brno) in 1843 and changed his baptized name Johann to Gregor. Cyril Knapp (1792-1867) was abbot of St Thomas’ Abbey, and was also interested in science, especially plant cultivation and animal husbandry. He built a greenhouse (greenhouse) for Gregor to pursue plant breeding. The questions to investigate, Abbott Knapp said, are “what is inherited and how?” These questions motivated Mendel in his experiments.

Between 1857 and 1864, Mendel conducted a series of plant-breeding experiments in the monastery garden, which were impressive for their intelligence in planning, observation, and analysis, as well as in the interpretation of results. His experiments were designed with great thought to answer questions about the characteristics of sons in relation to those of the parents. He collected data on tens of thousands of pea plants over multiple generations and kept counts of calculated characteristics and proportions. He was looking for generalizable laws from numerical data. It has been very successful. Mendel represented a member of the 19th-century intellectual community that derived laws (“Mendel’s laws”) from counts and lineage.

He submitted a paper entitled “Experiments in Plant Hybridization” containing the results of his experiments to the Society for the Study of the Natural Sciences at Brunn in 1865. One scholar (Lauren Easley) wrote, “The audience listened steadfastly. … ventured into a question, and not a single heartbeat quickened. … A lonely soul did not understand him.” Mendel’s paper was published in the Proceedings of the Meeting in 1866. However, there were only three citations for his work in the scientific literature over the next 35 years.

After 35 years of neglect, in 1900, three botanists – Hugo de Vries (Netherlands), Karl Korens (Germany) and Erich von Chermack (Austria) – independently confirmed his work. Mendel’s laws became well known.

It is remarkable how quickly scientists discovered that Mendel’s findings apply not only to pea plants but also to humans. Archibald Jarrod declared in 1902 that transmission of the human disease called alkaptonuria – a disease with many manifestations including discoloration of the skin and darkening of the sweat – complies with Mendelian laws.

Unfortunately, the rational basis of Mendelism was completely undermined during Stalin’s rule (1878-1953). The agronomist Trofim Lisin (1898-1976) convinced Stalin to believe that environmentally modified characteristics were heritable across all cells of an organism. This provided evidence for the Marxist concept of societal development. Stalin banned Mendelian genetics in Russia and in all countries under Russian influence.

Although Mendel introduced an evidence-based model of inheritance, his contribution remained unappreciated and was buried for 35 years. We can only speculate why. First, it was “premature” finding it. Those who make early discoveries may be ridiculed by their peers. Mendel was lucky that he was just ignored. Secondly, he was a monk and did not officially belong to the scientific establishment. Scientists do not usually accept discoveries by people outside their institution. Third, the scientific method used by Mendel was revolutionary in his time. He was perhaps the first botanist to seriously apply mathematics to biology. Botanists work by observation, not by experiment. The results of experiments by natural scientists, such as Charles Darwin, were judged by observation rather than by calculation. This is undoubtedly the reason for Mendel’s success, but it is likely a reason why the natural science world is not yet ready for his findings. Fourth, he was shy and did not loudly promote his discovery.

The historical neglect of Mendel’s scientific contribution has many lessons for us. Our minds should be open to absorbing new ideas, even if they are radical. Today, the words “new” and “innovation” are widely used. However, I’m not sure that if Mendel arrived today with a “premature” discovery, scientists would warmly welcome him and his discovery. Scientists have certainly learned to appreciate the importance of interdisciplinary approaches to science, but they are not yet free from bias and are not yet friendly to ideas generated outside of their institution.

The treatment of Mendelian principles by Lysenko, who was director of the Institute of Genetics in the USSR, in the 1940s also offers us lessons. Lysenko’s attack on Mendelian science and his cunning for putting forward a theory (the inheritance of environmentally acquired characters), not based on any scientifically derived evidence but ideologically appealing to a totalitarian regime, led to the persecution – and even death – of many scientists who opposed or supported Mendel’s theory. We are now witnessing a celebration of pseudoscience that aligns with ideology, in India as well as elsewhere. Disaster is bound to occur when society abandons reliance on scientific evidence, and political ideology and beliefs occupy a central place. Let us loudly support evidence-based science and rejoice strongly against ideology-based science. It would be a fitting tribute to Mendel on his 200th birthday.

The writer is the National Chair of Science (Scholarly Distinction), Government of India

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