Gregor Mendel's pea plant experiments lead to his theory on the principles of inheritance.
Date: 1860
Using experiments with pea plants, Austrian monk Gregor Mendel tracks how different characteristics travel across generations. He calls this action "heredity." By combining several fields, including mathematics, statistics, and physics, he is able to develop a relationship between "characteristics" and physical appearance through what he terms "dominant" and "recessive" traits. His work will remain largely unknown until much later, when the field of genetics begins to emerge and refers to his theories as "Mendelian genetics."