Teach yourself genetics / by R. J. Berry.

  • R. J. Berry
Date:
[1965], ©1965
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Teach yourself genetics / by R. J. Berry. Source: Wellcome Collection.

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    2 GENETICS mixed together in the offspring. Referred to as blending inheritance, this idea received apparent support from the work of early plant breeders. They crossed different species of plants and found that the progeny, if any, were usually intermediate in form between the parents. These erroneous views were current when Darwin formulated his theory of evolution (in The Origin of Species, 1859). As a result, that part of his theory which deals with the origin and main¬ tenance of variation is the weakest part of his argument (he was aware of the inadequacy of the theory of blending in¬ heritance as an explanation of observed facts, and used it only for want of something better). The modern science of genetics began with the work of Gregor Johann Mendel (1822—1884), an Austrian monk who lived at the Augustinian monastry at Brünn. He carried out breeding experiments with garden peas, crossing varieties with different heights, flower colour, seed colour etc., and explained the results with hypotheses which have stood before the most ingenious tests that geneticists have been able to devise. This remarkable work was published in 1866 in the proceedings of the local natural history society. It lay neglected in that obscure journal until 1900, when three biologists (De Vries in Holland, Correns in Germany and von Tschermak in Austria) came to similar conclu¬ sions independently from their own experiments. This led them to search through published work on inheritance, where they discovered Mendel's original paper, and had to ack¬ nowledge him as their forerunner. In the sixty years since then genetics has progressed far. Only the most important landmarks along the way can be mentioned here. Bateson, in Great Britain, discovered the phenomenon of linkage in 1908; Morgan, in the U.S.A. established the physical basis of heredity in 1919; Muller, also in the U.S.A., succeeded in inducing mutations arti¬ ficially in 1928; Benzer in America, and Watson, Crick and Pontecorvo in this country, have elucidated much of the fine structure of the gene in recent years. These discoveries