Social environment and moral progress / by Alfred Russel Wallace.

  • Alfred Russel Wallace
Date:
1913
Catalogue details

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

Credit: Social environment and moral progress / by Alfred Russel Wallace. Source: Wellcome Collection.

    117/180 page 105
    XV] Heredity and Environment blackbird or a six-toed kitten appears, but these are equally innate, and are often strongly inherited. All these are subject to variation, and can therefore be modi¬ fied by selection, whether natural or arti¬ ficial, and the effects of such selection in the case of domestic animals is often enormous. Such are the pouters and tumblers among pigeons, the bull-dog and the greyhound, the numerous breeds of poultry, all of which are known to have been produced by artificial selections of favourable variations extending over many centuries ; and the characters of these varieties are all strongly inherited. Characters which are acquired during the life of the individual owing to differ¬ ences in the use of certain organs or of exposure to light, heat, drought, wind, moisture, etc., are comparatively very slight, and are liable to be so combined with innate characters and with the effects of natural or artificial selection, that it is exceedingly difficult to ascertain, without such careful and long-continued experi¬ ments as have not yet been made, whether they are in any degree transmissible from parent to offspring, and therefore cumula¬ tive. 105
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