Genesis of Genetics. The growing Knowledge of Heredity before and after Mendel (A brief historical synopsis written in honor of the Institutum Gregorio Mendel and the International Symposium on Medical Genetics held in Rome, 6-7 September 1953)
Authors: Mayer Claudius Francis 
Published: July 2016

The historiography of genetics is not very extensive. As a tribute to Gregor Mendel the Genesis of modern Genetics is briefly described in its full range, from the Paleolithic Age to Lysenko. Since the earliest times, the knowledge of heredity had been growing in proportion with the development of ideas on reproduction and continuity of the species. For various forms of life, the basic problems of interest remained essentially the same during all historical periods; only the emphasis shifted from the gross to the more detailed, and the answers oscillated between the theories of preformation and epigenesis. Against this historical background, Mendel and the Mendelian laws stand out as the basic foundation of genetics.

The vital growing ideas on generation and evolution of plants, animals, and man are briefly reviewed and exposed as they had occurred before and after Mendel. The historical sketch leads us to ancient Assyria, India, the biblical times, and the classical Antiquity, to the early Greek philosophers and physicians whose works are sampled to illustrate the ancient beliefs concerning the role of male and female semen in generation, and concerning the proportional share of parents in the formation of body and mind of the offspring. The medieval knowledge on heredity is at its highest in the writings of Albertus Magnus whose work represents the refinement of scholastic science.

In these earlier times people did not know the exact functions of the organs of generation, or the true nature of sex. After the invention of the microscope in the 16th, and with a more liberal spirit of research in the 17th centuries, the sexual life and the male and female germ cells of many bisexual beings, including man, were gradually discovered during the 200-year period from 1677 to 1877. This happened with all sorts of speculation about heredity and about the origin and evolution of life. Meanwhile, many practical and theoretical hybridizers saw the various peculiarities in the filial generations, and many observed normal and abnormal characters transmitted from parents to offspring. Yet, none could formulate these observations into a mathematical regularity of inheritance until the reports of Gregor Mendel in 1865 on the result of his plant-crossings.

His discovery was buried, however, until 1900 when other biologists came to the same results, and revived and accepted his rules as the laws of heredity. From then on, modern genetics advanced rapidly and branched into many activities, everywhere fully supporting the views of Mendel. Thus, Mendel is truly the father of genetics, except for communist Russians whose political theories demand the denial of Mendelian heredity and the adherence to older discarded theories.

Genetics has the destiny to solve many practical problems in the life of nations, and to investigate a number of important yet unknown factors, in order to utilize the gene theory of heredity, and the “nuclear energy”, for a wider and brighter service of humanity.