A GENETIC PORTRAIT CHART 



According to Sir Francis Galton 



In Which the Size of Each Likeness Shows the Proportion Which Each Ancestor 

 Plays in the Children's Inheritance 



David Fairchild 



DID you ever find in the attic an 

 old daguerreotype of some ances- 

 tor and wonder at the mystery of 

 his blood relationship to you? Did you 

 ever get together the photographs of 

 all those whose actual bodily existences 

 have contributed to your own? When 

 you stop to think that these pictures of 

 their faces are all that is visible today 

 of those from whom you get your owm 

 nose, the cut of your chin, your expres- 

 sion, do they not seem worth preserv- 

 ing? Was it not after all into their 

 faces that their friends looked to read 

 their character when they were alive? 

 They are not merely photographs of 

 your grandparents as they sat for a 

 moment in the studio of some forgotten 

 photographer. They are the imperish- 

 able reflections cast by those wonderful 

 personalities which have made you 

 what you are. 



In what proportion have these an- 

 cestors contributed to your particular 

 person ? 



Sir Francis Galton, whose studies on 

 human inheritance blazed the first real 

 trail into this strange forest of ignor- 

 ance, has shown that, if one should take 

 a square to represent his total in- 

 heritance, one-half would represent the 

 influence of his parents; one-half of 

 what remained of the square would 

 represent the influence of his grand- 

 parents; one-half of what still remained 

 would be due to his great grandparents, 

 one-half of the remaining portions to 

 his great great grandparents, and so on 

 in regular diminishing proportion. 



This theory of inheritance, while not 

 explaining many things, helps one to 



Note. This Genetic Portrait Chart was prepared by Mr. Fairchild for personal use, and he was 

 naturally quite reluctant to publish it. On the ground, however, that it might arouse an interest 

 in the subject of inheritance among those people who have little knowledge of plants and animals, 

 photographs of which are featured in the Journal, the Council of the Association urged its publica- 

 tion. The system of designating relationships outlined by Dr. Bell in another article is used in this 

 discussion. — Editor. 



understand how quickly the influence 

 of distant ancestors diminishes until, 

 for example, that of a great grand- 

 parent is only one-sixteenth as much as 

 a grandparent and only one-sixty- 

 fourth that of a parent. To state the 

 case in another way: the chances that 

 one will resemble his great grandfather 

 are only one-sixteenth as great as that 

 he will resemble his father and one- 

 fourth as great as that he will look like 

 his grandfather. 



HUMAN HEREDITY CHARTED BY 

 PHOTOGRAPHS 



Since the ordinary chart has too little 

 in it that appeals to the imagination, 

 I have covered each square with its 

 corresponding ancestral photograph 

 with the result shown in the ac- 

 companying Genetic Portrait Chart. 



The bulk of people who are interested 

 in the general subject of genetics are 

 not familiar with the plants or animals 

 on which geneticists are making their 

 experiments (out of which are coming 

 great discoveries). They cannot easily 

 understand the significance of the 

 hereditary changes which are quite 

 apparent to the experimenters. They 

 are accustomed, however, to looking 

 at photographs of faces, and my idea 

 in publishing this arrangement of my 

 children's ancestors is to interest this 

 class of the members in their own 

 ancestors and get them to make 

 Genetic Portrait Charts which will 

 interest a considerable number of their 

 own intimate friends and perhaps alter 

 their point of view somewhat, bringing 

 it more nearly in line with that of the 



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