An introduction to the study of social evolution; the prehistoric period . will be blue-eyed; whenboth parents have brown iris either all the children willhave brown iris or else about a quarter will be blue-eyed.^- Professor Boas found that among Indian half-bloods an extensive series of measurements of width offace showed a decided tendency in the children to resem-ble either the Indian race or the White race. The fea-ture of Mendelian inheritance which brings about theoccurrence of mixed characters in the first hybrid gener-ation was not found, but instead of this a decided ten-dency of rev
An introduction to the study of social evolution; the prehistoric period . will be blue-eyed; whenboth parents have brown iris either all the children willhave brown iris or else about a quarter will be blue-eyed.^- Professor Boas found that among Indian half-bloods an extensive series of measurements of width offace showed a decided tendency in the children to resem-ble either the Indian race or the White race. The fea-ture of Mendelian inheritance which brings about theoccurrence of mixed characters in the first hybrid gener-ation was not found, but instead of this a decided ten-dency of reversion to either type and a comparative rarityof intermediate forms. 11 Thomson & Geddes, op. cit, p. 132. 12 Davenport, C. B.—Heredity in Ielation to Eurjcnics, p. 31,l^Poas, 7,—The Mind of Primilirc. Mrin, 1011, p. 78, 16 SOCIAL EVOLUTION Mendels theory like Weismaiins has the idea of ger-minal continuity for one of its foundations. It conceivesof the hereditary relation as one between the parentaland filial germ cells and not between the bodies of parent RED. FiGUEE 6. Mendelian Inheritance in Four-oclocks. and offspring. Mendelism explains the organism asbuilt up of a number of definite and separably inheritablecharacters. Variation seems to consist in the presenceor omission of elementary factors. Thus, the white sweetpea was brought about in the variation by which one ofthe color factors was drnjiped out. Variation is notalways the progression from a lower degree of com- VARIATION AND HEREDITY 17 plexity to a higher, but the reverse may bo true. Thusexperimental breeding lias shown that the white coat ofthe horse is not a simpk^ character, but is due to severalindependently inheritable factors.^^ Besides the IMendelian theory of inheritance there isone other theory: Francis Gallons theory of theory as first expounded was based upon the meas-urements of the stature of over 900 English found that the form of the body of an individualis
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectsociolo, bookyear1913
