IT IS the part of wisdom when about to give a dissertation which one hopes will at once instruct and entertain, to provide at the outset some definition of the subject matter. Genetics is the study of the heritable components of variation; the heritable factors which determine the range or extent of diversity. So, genetics is concerned with heritable differences and likenesses between individuals and between species. One emphasizes the differences because one can be certain of genetic determination of a particular characteristic only when it exists in a population in two or more alternative forms. It is the variants which catch the eye and hold the attention of the investigator, and which by their presence suggest more than one form of the gene or genes which determine that particular characteristic. I would like in what follows to present some examples of investigations of some aspects of genetics in human populations.
ADRENAL HYPERPLASIA
Several years ago Dr. Melvin Grumbach and I studied the genetics of adrenal hyperplasia, using as our material the patients of Dr. Lawson Wilkins. Since the disease occurs in more than one member of a sibship and since parents are unaffected, we suspected that it was genetically determined and that the affected patient possessed a double dose of a mutant gene; that is, the characteristic was recessive.
Relationship Between Root and Yield Related Morphological Characters in Pea (Pisum Sativum L.)
