Two noted authorities here discuss the latest facts and theories about heredity, and the roles of genes, environment, geography, culture, the interrelationships of parents, other children, relatives and friends, eugenics, and race in combining to produce the infinite variety of people that makes up the human race.

THE AUTHORS:

L. C. DUNN, a Professor of Zoology at Columbia, is the author (with E. W. Sinnott) of a standard textbook, "Principles of Genetics," and of ''Heredity and Variation.'' He is a member of the American Philosophical Society and the National Academy of Sciences.

THEODOSIUS DOBZHANSKY, Professor of Zoology at Columbia, is the author of "Genetics and the Origin of Species." He is a member of the American Philosophical Society and the National Academy of Sciences.