Anthropology and modern life / by Franz Boas.

  • Franz Boas
Date:
[1929]
Catalogue details

Licence: In copyright

Credit: Anthropology and modern life / by Franz Boas. Source: Wellcome Collection.

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    that has originated through migration will grad- ually become more homogeneous, if the descend- ants continue to reside in the same spot. In our cities and mixed farming communities, on account of changes in selective mating, constant changes in the hereditary composition are going on, even after immigration has ceased. Local inbreeding produces local types; avoidance of marriages be- tween near relatives favors increasing likeness of all the family lines constituting the population; favored or proscribed cousin marriages which are customary among many tribes establish separate family types and increase in this sense the heterogeneity of the population. Another question presents itself. We have con- sidered only the hereditary stability of genetic lines. We must ask ourselves also whether environ- mental conditions exert an influence over races. It is quite obvious that the forms of lower organisms are subject to environmental influences. Plants taken from low altitudes to high mountains develop short stems; leaves of semi-aquatic plants growing under water have a form diflfering from the subaerial leaves. Cultivated plants transform their stamens into petals. Plants may be dwarfed or stimulated in their growth by appropriate treat- ment. Each plant is so organized that it develops a certain form under given environmental condi- tions. Microorganisms differ so much in different
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