. Body-build and its inheritance. Heredity; Human anatomy. SEGREGATION IN HEREDITY. 149 35. Where the mode is at 33 it is probable that an S and an M gamete have met; and this condition is relatively common just because M gametes are common. The mode at 35 may arise from an F gamete carried in a heterozygous M uniting with an S gamete. The S gamete carried in heterozygous M may be responsible for a probable mode which is hidden in the form of a hump at 28 in figure 52. Attention is called to the probable influence of these modes on the two modes shown in figure 7, at 33 and 35 respectively. Th
. Body-build and its inheritance. Heredity; Human anatomy. SEGREGATION IN HEREDITY. 149 35. Where the mode is at 33 it is probable that an S and an M gamete have met; and this condition is relatively common just because M gametes are common. The mode at 35 may arise from an F gamete carried in a heterozygous M uniting with an S gamete. The S gamete carried in heterozygous M may be responsible for a probable mode which is hidden in the form of a hump at 28 in figure 52. Attention is called to the probable influence of these modes on the two modes shown in figure 7, at 33 and 35 respectively. These two modes are strong evidence for a segregation in the factors for build. Thus the very irregularity of the polygon of figure 7 is evidence of the presence of segregating factors for build. Moreover, these two modes appear at every age from birth to maturity, as is clearly shown in figure 53. This bimodality is easily accounted for on genetical grounds, but is inexplicable upon the bare nutritional hvpothesis of build. On the Number of Factors Involved in Fleshy Build. It is by no means an easy matter to determine the number of inde- pendent factors which are active in the case of a trait that is due to multiple factors. This matter is still less easy if there is only very imperfect dominance approaching intermediacy of the trait in the progeny of the F, mating. Yet that is the situation that has to be met in the study of heredity of build. An attempt has been made in this paper to test the relative prob- ability that there are only two, on the one hand, or three or more. Fig. 51.—Polygon of distribution of offspring of M X F matings from Appendix table XI), sexes separate and combined. See also legend of fig. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Davenport, Charles Benedict, 1866-1944.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecthumanan, bookyear1923
