Gregor Mendel: The Father of Genetics

Nov 10, 2020

Gregor Mendel, also known as the father of genetics. Image source.

By Madison Williams

Do you ever wonder how scientists can predict that parents will pass a disease on to their children? Gregor Mendel, the father of genetics, began this process of understanding genetic traits in the 1800s using pea plants. In this article, you will learn about his life and what led him to making this incredible discovery.

Gregor Johann Mendel was born into a poor family in Silesia (now the Czech Republic) on July 22, 1822. While education was important to him and his family, they struggled to pay for him to attend school. However, the local priest in his village persuaded his parents to send him away to school. He later attended the Philosophical Institute of the University of Olmütz, where he studied philosophy, mathematics, and physics. He thrived as a student, and he completed his education in 1843.

As the only male child in his family, he was expected to take over the family’s farm as he got older. However, he chose to enter Altbrünn monastery, and he was given the name of “Gregor” there. During his time at the monastery, he continued to expand his knowledge of science while serving as a priest and visiting sick parish members. He later left the monastery to pursue further scientific education at the University of Vienna.

After he pursued his education, he returned to the monastery to teach in the Brünn Realschule, the secondary school in the village. He only taught for two years, and took on administrative duties at the school. He then began his ground-breaking study that has allowed us to develop the field of genetics.

The monastery gave him permission to begin his study, and then the work began. It was widely known at the time that farmers had been able to selectively breed their animals and plants to achieve different types of offspring. He chose the pea plant (Pisum sativum) for its ease of pollination control, different varieties, and successful breeding. 

He chose to examine seven different traits, including seed color (yellow or green) and height of the plant (tall or short). He selectively crossed plants with different types of one trait–one purple (RR) and one white (rr), for example (see figure below). He noticed that in his first set of offspring (F1), one trait was expressed (purple), but the other was not. He called the expressed trait “dominant” and the unexpressed trait “recessive”, and these are terms we still use today. When he later crossed these offspring (Rr) with each other, the recessive trait appeared in some, yet some still presented the dominant trait in a 3:1 ratio of dominant to recessive traits. Mendel learned that this ratio could also be written as 1:2:1, denoting that two of the offspring were hybrids (Rr) and the other two were true-breeding (RR or rr), meaning that their appearance was truly representative of their breeding.

This figure represents Mendel’s pea plant study. It is shown that two hybrid plants are crossed, and that there are four different possible genetic outcomes. Two offspring are true-breeding, and two are hybrid. Image source.

Mendel discussed his findings in his paper called “Experiments on Plant Hybrids”; however, he received little attention for these findings at the time. Mendel made no significant efforts to continue sharing his work, although we do know that some of his papers were distributed. He died at 61 years old due to kidney failure. His work was later rediscovered by multiple botanists who continued his work and brought us to our understanding of genetics today. What do you think may have happened if Mendel had taken over his family farm instead of going to the monastery? Would he still have done his famous experiments? If not, do you think someone else would have done the same experiment or something different?

Edited by Meryem Ok and Candice Crilly