The complex, profound, and often controversial moral issues raised by our developing techniques and new knowledge of genetics are here examined by a distinguished scientist who is deeply concerned for the humanity of humankind. Dr. Dobzhansky discusses the inborn differences of every individual, including identical twins; the combined effect of heredity and environment; racial characteristics; the genetic dangers of "fallout"; and the future attempts that science will make to improve the human species by artificial selection and the planned breeding of genius. Here are facts alongside fascinating speculations-a picture of where the human race is heading and how it will get there,