Mendel's Paper on the Laws of Heredity (1866): Solving the Enigma of the Most Famous ‘Sleeping Beauty’ in Science
Published Online: 6 MAR 2017
Source/Fonte: The Mendel Legacy
For more than 150 years now the enigma of the disregard of the basic laws of heredity detected by Mendel in the 1860s for at least 34 years (from 1865 to 1900) has inspired a large number of conjectures and speculations. The most common of these proposals have been briefly listed and critically assessed. However, the well-argued answer given already at the beginning of the twentieth century by several pioneers of genetics including Correns, de Vries, Tschermak-Seysenegg, Bateson, Johannsen and others, and corroborated by further biologists and historians of biology in the more than one hundred years that followed, has not been adequately considered so far in the history of science in particular and in the public eye in general: The failure to accept the elemental laws of heredity for decades was due to the almost unlimited predominance of Darwin's theories on heredity and evolution. Darwin and his followers believed in the inheritance of acquired characteristics and blending inheritance as well as continuous evolution. Mendel rejected all three hypotheses. On the basis of hereditary constant elements (which he assumed to be independent of any environmental effects), he, in contrast, concluded ‘that species are fixed within limits beyond which they cannot change’ and completely rejected (what we today call) Lamarckism. Since there can be no doubt concerning Darwin's overwhelming victory in the battle for the scientific minds in the nineteenth century, there was no room left for the genuine laws of heredity until 1900. Their ‘rediscovery’ strongly reinforced the eclipse of Darwinism until the establishment of the modern synthesis in the 1930s and 1940s.
Critically assessing the most commonly proffered reasons for the neglect of Mendel's work.
Analysing and corroborating the arguments of several pioneers of genetics as well as further biologists and historians of science for the disregard of the basic laws of heredity: Darwinism versus Mendel.
Because there is no doubt concerning Darwin's overwhelming victory in the battle for the scientific minds in the nineteenth century, Mendel's February 1865 lecture was even met with ‘scornful laughter’ and was furthermore disregarded by most scientists as irrelevant for biology in general and heredity in particular until about 1900.
After careful experiments with Ficaria and other plant species, Mendel rejected the inheritance of acquired characteristics which Darwin had approved and tried to justify by his pangenesis hypothesis, which Stebbins called an ‘unfortunate anomaly’ and Klein to be ‘completely wrong’.
Reasons why Mendel was convinced that the laws he had detected validated Gärtner's conclusion ‘that species are fixed with limits beyond which they cannot change’.
Mendel was well aware of the evolutionary theories up to his time. In his library there was even Erasmus Darwin's Zoonomia (German edition in 1795–1799). He also collected and studied all the works of Darwin and other evolutionary authors right after their publication – the first German edition of the Origin was published in 1860.
The negative reactions of the Darwinian schools after the ‘rediscovery’ of Mendel's work – ‘The controversy became so bitter that in 1903 the British periodical Nature closed its columns to the Mendelians’ – subsequently led to the eclipse of Darwinism until the formulation of the modern evolutionary synthesis (the ‘marriage’ between Darwin and Mendel) in the 1930s and 1940s.
Mendel;laws of heredity; reasons for disregard; ‘rediscovery’ of; constant elements; stability of species; Darwin; inheritance of acquired characteristics; pangenesis; evolution; evolutionary theories before 1856