It took the patience of a monk to unravel the basic laws of inheritance. For thousands of years farmers and herders selectively bred their crops and livestock to produce more useful varieties. However, this process was often unpredictable since no one understood the rules that governed heredity. These rules were finally discovered from painstaking breeding experiments carried out between 1856 and 1863 by an obscure Austrian monk named Gregor Mendel. Mendel’s experiments laid the foundation for the scientific study of heredity, called genetics. Today, Mendel is rightly known as the father of modern genetics.
Mendel was born on July 22, 1822, in Heinzendorf, Austria (now Hyncice, near Krnov, in what is now the Czech Republic). In 1843, Mendel entered the monastery of St. Thomas in Brunn, Austria (now Brno, the Czech Republic). He became a priest in 1847. In 1851, the monastery sent Mendel to study science and mathematics at the University of Vienna. He returned to the monastery in 1853. Mendel’s fame came from his experiments he conducted in the monastery garden.
In a series of now-famous experiments, Mendel patiently bred and crossbred thousands of pea plants and recorded the characteristics of each successive generation. Mendel concluded that plant traits are handed down through hereditary elements now called genes. He reasoned that each plant receives a pair of genes for each trait, one gene from each of its parents. Based on his experiments, he concluded that if a plant inherits two different genes for a trait, one gene will be dominant and the other will be recessive. The trait of the dominant gene will appear in the plant. For example, the gene for round seeds is dominant, and the gene for wrinkled seeds is recessive. A plant that inherits both genes will have round seeds. Mendel also concluded that the pairs of genes segregate (separate) in a random fashion when a plant’s gametes are formed. Thus, a parent plant hands down only one gene of each pair to its offspring. In addition, Mendel believed that a plant inherits each of its traits independently of other traits. These two conclusions are today known as Mendel’s Law of Segregation and his Law of Independent Assortment.
Mendel published his work in 1866, demonstrating the actions of invisible “factors”—what we now call genes —in providing for visible traits in predictable ways. Mendel’s research was with plants, but the basic underlying principles of heredity that he discovered also apply to people and other animals because the mechanisms of heredity are essentially the same for all complex life forms.
Gregor Mendel never enjoyed recognition for his scientific achievements in his lifetime. His published papers were largely ignored. Few scientists were willing to pay attention to the gardening experiments of an Austrian monk. But Mendel himself grasped the significance of his work even if others did not. Shortly before his death in Brünn on Jan. 6, 1884, Mendel said “My scientific studies have afforded me great gratification. I am convinced that it will not be long before the whole world acknowledges the results of my work.” However, it was not until 1900, when three different European scientists independently discovered the same principles governing inheritance, that the era of modern genetics began. Only later did scientists realize Mendel had made the same discovery decades earlier and grant him the recognition he never received in life.