MERGING OF ANCESTRAL LINES 



ANITA NEWCOMB McGEE 



Southern Pines, North Carolina 



All human beings who have lived in the ages since man first appeared on 

 earth may be divided into two groups, viz., those who are ancestors of the 

 people living today, and those who are not. In any long-distance view of 

 heredity, this distinction is fundamental. 



The study of which this paper is a small part is an attempt to throw some 

 light on the relative number and character of the first class, which I call "per- 

 manent ancestors." It is based on a very extensive, but connected, genea- 

 logical study running into all parts of Europe and in some lines for more than 

 forty generations. I remark in passing that such work is worthless unless 

 one is a natural doubter and constantly remembers the principles of histori- 

 cal criticism, applied especially to original sources. Some genealogy is pure 

 fiction, particularly in Europe, but if that is carefully weeded out, much of 

 real value to science remains. 



The ancestors of each and every living person fall naturally into three 

 groups; the men who are in his all-male line; the women who are in his corre- 

 sponding all-female line; and the rest in the mixed ancestral fines containing 

 both males and females which lie between the other two in a chart. The 

 male line, from its legal importance and in recent centuries its carrying 

 of the surname, has in the minds of the public, and even of some biologists, 

 a greatly exaggerated value. Its counterpart, the female line, is ignored by 

 all, but every person had a mother, and she a mother, on back in unbroken 

 line to the beginning of humanity, and still on to the beginning of sexual 

 reproduction, this line being at least of equal biological value with the male 

 line. Of course, the vast majority of any one's ancestors of either sex lie 

 in the mixed lines. 



Every one knows that although the number of one's ancestors necessarily 

 doubles with each ascending generation, after a time there appears in any 

 ancestral chart some individuals who are ancestors twice, thrice, or many 

 times over. This is caused by what I call the "merging of ancestral lines." 



The closest merging is that produced by successive matings of sibs (mean- 

 ing "Geschwister") as was known in ancient Egypt. This, and any other 

 close merging, is obviously the same as inbreeding viewed from the opposite 



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