In recent years, the field of genetics has undergone a revolution. Advances in computational tools and sequencing technologies that are both powerful and inexpensive have enabled researchers to make discoveries and push the boundaries of what is possible in the clinic. But this work traces back to one individual, who is now known as the father of genetics, Gregor Mendel.
Mendel was born on July 22, 1822 in what is now known as Czechia to a family of little means. He was able to get an education, however, and a professor recommended that he join the Augustinian monks, where he could pursue his studies. After being admitted to the order, he became a student at the University of Vienna, but his quiet personality did not seem suited for the teaching path he followed, and he was not able to pass the test for a teaching certificate. Instead, he retreated to his garden, where he began work that would not be appreciated until after his death.
Mendel was curious about hybrid pea plants and persisted in a careful examination of them for eight years. He took meticulous notes the entire time. The pea plants he used can be fertilized with their own pollen (self-fertilization) or the pollen from another plant (cross-fertilization), and that pollen can be easily manipulated with paint brushes. He took note of seven characteristics of these plants, such as pea color (green or yellow), or height (tall or short). His observations were remarkable and laid the foundation for a major branch of science even before DNA had been discovered.
In his work, Mendel first made sure that heritability was consistent by breeding plants through self-fertilization for two years; plants with green peas that self-fertilized consistently produced offspring that also had green peas, for example. Eventually, 22 types of plants were generated that had offspring with the same traits. These plants, whose genes would now be known as homozygous, were crossed to create hybrids. The hybrids that were produced were also crossed back to parental plants. During his research, Mendel would grow over 10,000 plants.
This research revealed many things; one example is that Mendel discovered that some traits are dominant. When two homozygous plants were crossed, their progeny were not a blend of the parents as people of the time expected. For example, a cross of a short and tall plant would not generate plants of medium height. Instead, all of the offspring of a tall and short plant were tall.
Scientists would eventually find that the reality in many organisms can be far more complex, of course. Not all forms of life pass traits down in this way, while some characteristics may also have varying levels of penetrance, or others can be sex-linked, for example.
Still, his studies led Mendel to other solid conclusions, including an understanding of recessive traits, and the very earliest ideas of gene alleles, even before people knew what genes were. Beyond plant crosses, he was also the first person to apply math to the study of inheritance.
He presented his findings to the Brunn Society for Natural Science on February 8, 1865. The following year, a paper was published. People noted that the research was thorough, but the significance was unappreciated. Mendel was simply too far ahead of his time, and many years would pass before the scientific community would realize what he had learned. He died of kidney failure at the age of 61. Now, he lives in history.
You can read Mendel's Laws of Heredity at the Cold Spring Harbor Laboratory DNA Learning Center.
Source: Nature Scitable
