New paths in genetics / by J.B.S. Haldane.

  • Haldane, J. B. S. (John Burdon Sanderson), 1892-1964.
Date:
1941
Catalogue details

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

Credit: New paths in genetics / by J.B.S. Haldane. Source: Wellcome Collection.

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    The Science of Genetics difference to nature, or heredity in a very broad sense of that word. Where experiment is possible we can generally find out whether a given distinction is due to nature or nurture. We can, for example, inbreed, and produce a pure line of plants or animals all of which have very nearly the same nature, and subject them to different nurtures. But this is almost impossible in the most inter¬ esting of all cases, that of man. However, even in man a few experiments have been performed on monozygotic twins, who have the same nature. I must emphasize that I do not regard the distinction between nature and nurture, or that between genotype and phenotype, which is somewhat similar, as an absolute one. This is clearly seen in the case of virus diseases. A potato may be obviously infected with a gross disease of this kind, which produces marked effects on transfer to other potatoes. Or a similar infection by grafting or otherwise may merely produce immunity to a known virus. We generally regard the virus as part of the environment, or nurture. But if it is transmitted to a plant from its mother, it cannot be distinguished from other extra-nuclear self-reproducing bodies, such as the chloroplasts, which are regarded as part of the plant's nature. If Lysenko^ is correct, there is no sharp line in the Solanaceae between viruses causing disease and graft- ^ Lysenko (1939). Translation in Science and Society, Spring 1940, p. 211. 13