Gregor Mendel, born in the year 1822 in what is now the Czech Republic, showed great intellect as a young boy. So much so that a priest convinced his family to send him away to a grammar school where he finished his studies in 1840. Mendel then went on to study philosophy, physics, and mathematics in university and later become a monk in the Augustinian order. His position at his monastery allowed him to be sent to the University of Vienna to continue his study of physics and mathematics. While there, he also studied microscopy and plant anatomy and physiology.
Pea Plants
When Mendel returned to the monastery, he was given permission from the abbot to conduct an experiment regarding the inheritance of traits. He chose to use pea plants in his study and proceeded to analyze characters which are broad categories like height, seed color, etc. After crossing pea plants with certain traits (such as tall height) with pea plants with dissimilar traits (such as short height), he noticed a pattern. This pattern showed some traits to be “dominant” while it showed others to be “recessive”. The dominant traits typically appeared in the offspring of the cross while the recessive traits did not. However, in the second generation, the recessive trait reappeared. In other experiments, Mendel crossed pea plants with multiple characters of interest. For example, he would cross a plant that was short and had a brown seed color with another plant that was tall and had a green seed color. He found that the inheritance of one character (height) did not influence the inheritance of another (seed color).
Mendel’s Theories
Using his experiments, Mendel arrived at three conclusions. One conclusion was that one type of trait will always be expressed over another (this is now known as the law of dominance). So, the trait for tall height will always be expressed over the trait for short height. Another conclusion was that characters are inherited separately from one another (this is now known as the law of independent assortment). So, the inheritance of a trait for height does not impact the inheritance of a trait for seed color. We are now aware that each character is influenced by a different gene and that these genes are inherited independently of each other. This aligns with Mendel’s thinking. The final conclusion was that different traits somehow separate from each other before reproduction (this is now known as the law of segregation). So, the trait for tall height is separated from the trait for short height (if an individual plant has both) and only one will be randomly inherited by the offspring. This conclusion supports the idea of alleles which are versions of the same gene that code for different traits. We now know that each person receives one allele for a gene from each parent, resulting in two alleles for every gene in an individual.
The Discovery of His Work
Though Mendel both published and presented his research, it went largely unnoticed for years. His experiments, having been introduced in 1865, were only recognized in the early twentieth century by botanists Hugo de Vries, Carl Correns, and Erick Tschermak. The recognition of his scientific contributions paved the way for Gregor Mendel to be known as “The Founder of Genetics”.
