THE STATUS OF MAN. 



Mendelian inheritance in man was demonstrated almost 

 simultaneously with the first work with animals, which showed 

 that the clue discovered by Mendel in his work with plants, 

 was going to be of the Very greatest importance for an insight 

 into heredity and evolution. 



It was soon apparent, that differences in characters of man- 

 kind were often due to uni-f actorial differences in genotype, and 

 that such differences could easily be traced through long series 

 of generations. Apart from differences in eye-colour and hair- 

 colour and such, most of the cases of inheritances of definite 

 genes in man have been those in which the lack, or in other 

 instances, the presence of a gene manifested itself as a patholo- 

 gical aberration. A few instances are colour-blindness, bra- 

 chydactily, alkaptonuria. 



Most of these studies on inheritance of characters in man 

 were at first conducted out of pure love of knowledge, without 

 afterthought, but, as some of the characters studied happened 

 to be undesirable ones from a medical or a sociological poiat 

 of view, the thought lay close, that some knowledge concerning 

 the inheritance of these characters was the first step toward 

 eliminating, or at least combating them. -' 



Of late years a good deal of interest in Eugenics, is evident, 

 and it is safe to say, that almost all the persons interested, hope 

 that from a study of inheritance in man some good for the 

 future of humanity may result. Only a limited number of in- 

 vestigators just happen to study the transmission and inter- 

 action of genes in man, instead of in some other organism, but 

 as from a genetic standpoint the material has very material 



