Gregor Mendel

Gregor Johann Mendel (July 20July 20 is his birthday; often mentioned is July 22, the date of his baptism., 1822 – January 6, 1884) was an Augustinian abbot who is often called the "father of genetics" for his study of the inheritance of traits in pea plants. Mendel showed that the inheritance of traits follows particular laws, which were later named after him. The significance of Mendel's work was not recognized until the turn of the 20th century. Its rediscovery prompted the foundation of genetics.

Biography

Mendel was born on July 20, 1822, in a German-speaking family of Heinzendorf in Silesia, part of the Austrian Empire (now Hynčice in the Czech Republic) and was baptized 2 days later. During his childhood Mendel worked as a gardener, and as a young man attended the Philosophical Institute in Olomouc. In 1843 he entered the Augustinian Abbey of St. Thomas in Brno. Born Johann Mendel, he took the name Gregor upon entering monastic life. In 1847 he was ordained as a priest. In 1851 he was sent to the University of Vienna to study, returning to his abbey in 1853 as a teacher, principally of physics.

Gregor Mendel, who is known as the "father of genetics", was inspired by both his professors at university and his colleagues at the monastery to study variation in plants. He commenced his study in his monastery's experimental garden. Between 1856 and 1863 Mendel cultivated and tested some 28,000 pea plants. His experiments brought forth two generalizations which later became known as Mendel's Laws of Inheritance.

Mendel's attraction to research was based on his love of nature. He was not only interested in plants, but also in meteorology and theories of evolution. Mendel often wondered how plants obtained atypical characteristics. On one of his frequent walks around the monastery, he found an atypical variety of an ornamental plant. He took it and planted it next to the typical variety. He grew their progeny side by side to see if there would be any approximation of the traits passed on to the next generation. This experiment was "designed to support or to illustrate Lamarck's views concerning the influence of environment upon plants." He found that the plants' respective offspring retained the essential traits of the parents, and therefore were not influenced by the environment. This simple test gave birth to the idea of heredity.

Mendel read his paper, "Experiments on Plant Hybridization", at two meetings of the Natural History Society of Brünn in Moravia in 1865. When Mendel's paper was published in 1866 in Proceedings of the Natural History Society of Brunn, it had little impact and was cited about three times over the next thirty-five years.

Elevated as abbot in 1868, his scientific work largely ended as Mendel became consumed with his increased administrative responsibilities, especially a dispute with the civil government over their attempt to impose special taxes on religious institutions. ^*

Mendel died on January 6, 1884, in Brno, Austria-Hungary (now Czech Republic), from chronic nephritis.

Rediscovery of Mendel's work

It was not until the early 20th century that the importance of his ideas was realized. In 1900, his work was rediscovered by Hugo de Vries and Carl Correns. Though Erich von Tschermak was originally also credited with rediscovery, this is no longer accepted as he did not understand Mendel's laws. Mendel's results were quickly replicated, and genetic linkage quickly worked out. Biologists flocked to the theory, as while it was not yet applicable to many phenomena, it sought to give a genotypic understanding of heredity which they felt was lacking in previous studies of heredity which focused on phenotypic approaches. Most prominent of these latter approaches was the biometric school of Karl Pearson and W.F.R. Weldon, which was based heavily on statistical studies of phenotype variation. The strongest opposition to this school came from William Bateson, who perhaps did the most in the early days of publicizing the benefits of Mendel's theory (the word "genetics", and much of the discipline's other terminology, originated with Bateson). This debate between the biometricians and the Mendelians was extremely vigorous in the first two decades of the twentieth century, with the biometricians claiming statistical and mathematical rigor, while the Mendelians claimed a better understanding of biology. In the end, the two approaches were combined as the modern synthesis of evolutionary biology, especially by work conducted by Ronald Fisher in 1918.

His experimental results have later been the object of considerable dispute. The renowned statistician R. A. Fisher analyzed the results of the F1 (first filial) ratio and found them to be implausibly close to the exact ratio of 3 to 1.Fisher, R. A. (1936). "Has Mendel's work been rediscovered?" Annals of Science 1:115-137. Only a few would accuse Mendel of scientific malpractice or call it a scientific fraud — reproduction of his experiments has demonstrated the accuracy of his hypothesis — however, the results have continued to be a mystery for many, though it is often cited as an example of confirmation bias, and he is generally suspected of having "smoothed" his data to some degree (not knowing about the importance of blind classification). The fact that his reported results concentrate on the few traits in peas, which are determined by a single gene, has also suggested that he may have censored his results, otherwise he would have stumbled across genetic linkage.

The standard botanical author abbreviation Mendel is applied to species he described.

Mendel, Darwin and Galton

Mendel lived around the same time as the British naturalist Charles Darwin (1809 – 1882) and many have fantasized about a historical evolutionary synthesis of Darwinian natural selection and Mendelian genetics during their lifetimes. Mendel had read a German translation of Darwin's Origin (as evidenced by underlined passages in the copy in his monastery), after completing his experiments but before publishing his paper. Some passages in Mendel's paper are Darwinian in character, evidence that The Origin of Species influenced Mendel's writing. Darwin did not have a copy of Mendel's paper, but he did have a book by Focke with references to it. The leading expert in heredity at this time was Darwin's half-cousin Francis Galton who had mathematical skills that Darwin lacked and may have been able to understand the paper had he seen it. In any event, the modern evolutionary synthesis did not start until the 1920s, by which time statistics had become advanced enough to cope with genetics and evolution.

Notes

Bibliography

William Bateson Mendel's Principles of Heredity, a Defense, First Edition, London: Cambridge University Press, 1902. On-line Facsimile Edition: Electronic Scholarly Publishing, Prepared by Robert Robbins
Robin Marantz Henig, Monk in the Garden: The Lost and Found Genius of Gregor Mendel, the Father of Genetics, Houghton Mifflin, May, 2000, hardcover, 292 pages, ISBN 0395977657; trade paperback, Houghton Mifflin, May, 2001, ISBN 0618127410
Robert Lock, Recent Progress in the Study of Variation, Heredity and Evolution, London, 1906
Reginald Punnett, Mendelism, Cambridge, 1905
Curt Stern and Sherwood ER (1966) The Origin of Genetics.
Colin Tudge In Mendel's footnotes ISBN 0099288753 book about Gregor Mendel
Bartel Leendert van der Waerden Mendel's experiments Centaurus 12, 275-288 (1968) refutes allegations about "data smoothing"
James Walsh, Catholic Churchmen in Science, Philadelphia: Dolphin Press, 1906

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