What is eugenics? / by Leonard Darwin.

  • Leonard Darwin
Date:
1932
Catalogue details

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

Credit: What is eugenics? / by Leonard Darwin. Source: Wellcome Collection.

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    СНАРТЕЕ III Our Surroundings E have seen that if animals showing good points are selected for breeding purposes, generation after generation, the result will be an improvement in the breed. This is because any good point noted in a parent as a rule will reappear to some extent amongst its descendants; or, in other words, it wiU generally be inherited. We have thus far accepted this as a fact merely because it is a matter of common knowledge. Doubts and difficulties are, how¬ ever, constantly being raised when it is proposed to apply this knowledge in human affairs. Something must, there¬ fore, be said to make this certainty doubly certain. As we have seen, every human being is developed out of a minute germ. These germs are at first quite indis¬ tinguishable from each other in appearance. Nevertheless, putting aside the case of twins, who resemble each other closely, now often called identical twins, no two germs are ever exactly like each other. And the differences between the germs are such as to give rise to differences between the individuals developing from them. Since no two germs are alike, no two human beings are alike either. And the differences between men, which result from differences between the germs from which they originated, are known as hereditary differences. If one man has blue eyes and another brown, this is as good an example as can be given of an hereditary difference. These are, however, not the only kind of differences which exist between human beings. Men meet with different surroundings as they are developing from their originating germs and, indeed, during aU their lives. The surroundings to which men are exposed may leave an indelible mark on them, and may thus make them differ 10