Gregor Mendel was an Austrian monk who discovered
the basic principles of heredity through experiments in his garden. Mendel's
observations became the foundation of modern genetics and the study of
heredity, and he is widely considered a pioneer in the field of genetics.
Synopsis
Gregor Mendel, known as the "father of modern
genetics," was born in Austria in 1822. A monk, Mendel discovered the
basic principles of heredity through experiments in his monastery's garden. His
experiments showed that the inheritance of certain traits in pea plants follows
particular patterns, subsequently becoming the foundation of modern genetics
and leading to the study of heredity.
Early Life
Gregor Johann Mendel was born Johann Mendel on July
22, 1822, to Anton and Rosine Mendel, on his family’s farm, in what was then
Heinzendorf, Austria. He spent his early youth in that rural setting, until age
11, when a local schoolmaster who was impressed with his aptitude for learning
recommended that he be sent to secondary school in Troppau to continue his
education. The move was a financial strain on his family, and often a difficult
experience for Mendel, but he excelled in his studies, and in 1840, he
graduated from the school with honors.
Following his graduation, Mendel enrolled in a
two-year program at the Philosophical Institute of the University of Olmütz.
There, he again distinguished himself academically, particularly in the
subjects of physics and math, and tutored in his spare time to make ends meet.
Despite suffering from deep bouts of depression that, more than once, caused
him to temporarily abandon his studies, Mendel graduated from the program in
1843.
That same year, against the wishes of his father,
who expected him to take over the family farm, Mendel began studying to be a
monk: He joined the Augustinian order at the St. Thomas Monastery in Brno, and
was given the name Gregor. At that time, the monastery was a cultural center
for the region, and Mendel was immediately exposed to the research and teaching
of its members, and also gained access to the monastery’s extensive library and
experimental facilities.
In 1849, when his work in the community in Brno
exhausted him to the point of illness, Mendel was sent to fill a temporary
teaching position in Znaim. However, he failed a teaching-certification exam
the following year, and in 1851, he was sent to the University of Vienna, at
the monastery’s expense, to continue his studies in the sciences. While there,
Mendel studied mathematics and physics under Christian Doppler, after whom the
Doppler effect of wave frequency is named; he studied botany under Franz Unger,
who had begun using a microscope in his studies, and who was a proponent of a
pre-Darwinian version of evolutionary theory.
In 1853, upon completing his studies at the
University of Vienna, Mendel returned to the monastery in Brno and was given a
teaching position at a secondary school, where he would stay for more than a
decade. It was during this time that he began the experiments for which he is
best known.
Experiments and Theories
Around 1854, Mendel began to research the
transmission of hereditary traits in plant hybrids. At the time of Mendel’s
studies, it was a generally accepted fact that the hereditary traits of the
offspring of any species were merely the diluted blending of whatever traits
were present in the “parents.” It was also commonly accepted that, over
generations, a hybrid would revert to its original form, the implication of
which suggested that a hybrid could not create new forms. However, the results
of such studies were often skewed by the relatively short period of time during
which the experiments were conducted, whereas Mendel’s research continued over
as many as eight years (between 1856 and 1863), and involved tens of thousands
of individual plants.
Mendel chose to use peas for his experiments due to
their many distinct varieties, and because offspring could be quickly and
easily produced. He cross-fertilized pea plants that had clearly opposite
characteristics—tall with short, smooth with wrinkled, those containing green
seeds with those containing yellow seeds, etc.—and, after analyzing his
results, reached two of his most important conclusions: the Law of Segregation,
which established that there are dominant and recessive traits passed on
randomly from parents to offspring (and provided an alternative to blending
inheritance, the dominant theory of the time), and the Law of Independent
Assortment, which established that traits were passed on independently of other
traits from parent to offspring. He also proposed that this heredity followed
basic statistical laws. Though Mendel’s experiments had been conducted with pea
plants, he put forth the theory that all living things had such traits.
In 1865, Mendel delivered two lectures on his
findings to the Natural Science Society in Brno, who published the results of
his studies in their journal the following year, under the title Experiments
on Plant Hybrids. Mendel did little to promote his work, however, and the few
references to his work from that time period indicated that much of it had been
misunderstood. It was generally thought that Mendel had shown only what was
already commonly known at the time—that hybrids eventually revert to their
original form. The importance of variability and its evolutionary implications
were largely overlooked. Furthermore, Mendel's findings were not viewed as
being generally applicable, even by Mendel himself, who surmised that they only
applied to certain species or types of traits. Of course, his system eventually
proved to be of general application and is one of the foundational principles
of biology.
Later Life and Legacy
In 1868, Mendel was elected abbot of the school
where he had been teaching for the previous 14 years, and both his resulting
administrative duties and his gradually failing eyesight kept him from
continuing any extensive scientific work. He traveled little during this time,
and was further isolated from his contemporaries as the result of his public
opposition to an 1874 taxation law that increased the tax on the monasteries to
cover Church expenses.
Gregor Mendel died on January 6, 1884, at the age of
61. He was laid to rest in the monastery’s burial plot and his funeral was well
attended. His work, however, was still largely unknown.
It was not until decades later, when Mendel’s
research informed the work of several noted geneticists, botanists and
biologists conducting research on heredity, that its significance was more
fully appreciated, and his studies began to be referred to as Mendel’s Laws.
Hugo de Vries, Carl Correns and Erich von Tschermak-Seysenegg
each independently duplicated Mendel's experiments and results in 1900,
finding out after the fact, allegedly, that both the data and the general
theory had been published in 1866 by Mendel. Questions arose about the validity
of the claims that the trio of botanists were not aware of Mendel's previous
results, but they soon did credit Mendel with priority. Even then, however, his
work was often marginalized by Darwinians, who claimed that his findings were irrelevant
to a theory of evolution. As genetic theory continued to develop, the relevance
of Mendel’s work fell in and out of favor, but his research and theories are
considered fundamental to any understanding of the field, and he is thus
considered the "father of modern genetics."
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