HUMAN LIFE 



fidently to make statements about the 

 heredity mechanism and beha.vior really 

 startling in their preciseness and practical 

 importance. We can make enough proph 

 ecies about the outcome of many cases 

 of mating to give us sufficient basis to 

 warrant us in modifying our social in 

 heritance in directions to increase ad 

 vantages or decrease disadvantages de 

 rived from biological inheritance. 



Before Mendel and the post-Mendel- 

 ians, about the only so-called law of 

 heredity that had been formulated was 

 Galton s generalization to the effect that 

 an individual receives one-half of his 

 inheritance from his two parents, one- 

 fourth from his four grandparents, one- 

 eighth from his eight great grandparents, 

 one-sixteenth from his sixteen great, 

 great grandparents and so on by de 

 creasing fractions back to the beginning 

 of ancestors, the total of these fractions 

 equalling 1, or the total biological inheri 

 tance of the individual. Very interesting, 

 but not very specific as to just what 

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