Habit and heritage / by Frederic Wood Jones.

  • Frederic Wood Jones
Date:
1943
Catalogue details

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

Credit: Habit and heritage / by Frederic Wood Jones. Source: Wellcome Collection.

    98/108 (page 94)
    94 HABIT AND HERITAGE he naturally shows all those germinal variations that we are accustomed to meet with among all other forms of life. Man, considered as a zoological type, is, as we should expect in a mammal that may truly be termed a ' domesticated animal a highly variable form. It is strange that Thomson should have declared that com¬ pared with most organisms, man is a slightly varying creature . That statement fie makes on more than one occasion in his work on Heredity and it is obvious that he attaches importance to it. But every human and comparative anatomist will be prepared to admit that the statement lacks any sort of validity. All the higher members of the Primates notoriously show a bewildering range of variation ; and it would be nearer to the truth to say that of all mammals man is the most variable, than to claim that he is a slightly varying creature . It is unnecessary to rehearse the enormous range that is covered by human variations that are well known to be true changes in germinal constitution. A vast amount of work has been done on the inheritance of these things and this work is permanent and remains, and must remain, beyond the possibility of any challenge as to its validity. Just as we must admit the importance of human external heritage, so must we admit the importance of the inheritance of an utiusual number of internal germinal variations, in any sort of inquiry into the whole question of human inheritance. But in addition to man's internal heritage of true germinal variations, the inheritance of which is admitted by all, he also exhibits, in a very high degree, the power of producing modifications as a consequence of use and of environment. Now this should be no surprise for us, since man is pre-eminently that form of life that has come to the occupation of almost every conceivable type of environment ; and that has become subjected to almost every possible sort of functional rôle as his life activity. Man may live ät the poles or at the equator ; he may wield a sledge-hammer or a pen as a daily occupation ; he may spend half a lifetime sitting