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Mendel's Discovery of the Mendelian Ratios

<p>Augustinian Abbey of St. Thomas in Brno</p>

Augustinian Abbey of St. Thomas in Brno

In 1866 Austrian scientist and friar of the Augustinian Abbey of St Thomas in Brno (now Czech Republic) Gregor Mendel published "Versuche ber Pflanzen-Hybriden," Verhandlungen des naturforscheden Vereines in Brünn 4 1865, [3]-47 (1866). Reporting Mendel's eight years of experimental work on artificial plant hybridization, this paper recorded the discovery of the Mendelian ratios, the most significant single achievement in the history of genetics. Working with clearly identifiable traits in the pea plant, (seed color and shape, stem length, position of the flowers) Gregor Mendel discovered a generalized set of rules concerning heredity. He postulated that there are discrete units of heredity (what we call genes) that are transmitted from generation to generation even though some of these are not expressed as an observable trait in every generation. He discovered dominant and recessive traits— what we call segregation and what we call alleles

"In comparison with his predecessors, Mendel was original in his approach, and in his interpretation of experimental results. He reduced the hitherto extremely complex problem of crossing and heredity to an elementary level appropriate to exact analysis. He left nothing to chance. . . . Altogether new was his use of large populations of experimental plants, which allowed him to express his experimental results in numbers and subject them to mathematical treatment. By the statistical analysis of large numbers Mendel succeeded in extracting "laws" from seemingly random phenomena. This method, quite common today, was then entirely novel. Mendel, inspired by physical sciences, was the first to apply it to the solution of a basic biological problem and to explain the significance of a numerical ratio" (D.S.B.).

Published in the obscure journal of a provincial natural science society, Mendel's work went virtually unnoticed, and remained so until 1900 when the Mendelian ratios were independently rediscovered by Hugo de Vries, Carl Correns and Erich von Tschermak.

♦ In February 2012 Mendel's original manuscript of his famous paper was returned to the Mendel Museum at the Augustinian Abbey of St. Thomas in Brno. The monastery had been closed down in 1953 at which time the manuscript was hidden by the Augustinian monks. In the 1980s the manuscript was sent for safekeeping to Vienna, and then to Germany.  After much negotiation between the Czech Republic and Germany the manuscript was returned to the place of its origin.

Dibner, Heralds of Science no. 35. Norman, Morton's Medical Bibliography (1991) no. 222. Horblit, One Hundred Books Famous in Science no. 73a.  Carter & Muir, Printing and the Mind of Man (1967) no. 356.  Hook & Norman, The Haskell F. Norman Library of Science and Medicine (1991) no. 1490.

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