The Genetic Effects of Radiation By ISAAC ASIMOV and THEODOSIUS DOBZHANSKY Contents THE MACHINERY OF INHERITANCE 1 Introduction 1 Cells and Chromosomes 2 Enzymes and Genes 5 Parents and Offspring 8 MUTATIONS 10 Sudden Change 10 Spontaneous Mutations 13 Genetic Load 16 Mutation Rates 19 RADIATION 22 Ionizing Radiation 22 Background Radiation 27 Man-made Radiation 30 DOSE AND CONSEQUENCE 32 Radiation Sickness 32 Radiation and Mutation 33 Dosage Rates 37 Effects on Mammals 40 Conclusion 43 SUGGESTED REFERENCES 47 THE COVER [Illustration: The cover design embodies a radiation symbol, a stylized karyotype of human chromosomes, and a genealogical table.] THE AUTHORS [Illustration: ISAAC ASIMOV received his academic degrees from Columbia University and is Associate Professor of Biochemistry at the Boston University School of Medicine. He is a prolific author who has written over 65 books in the past 15 years, including about 20 science fiction works, and books for children. His many excellent science books for the public cover subjects in mathematics, physics, astronomy, chemistry, and biology, such as _The Genetic Code_, _Inside the Atom_, _Building Blocks of the Universe_, _The Living River_, _The New Intelligent Man’s Guide to Science_, and _Asimov’s Biographical Encyclopedia of Science and Technology_. In 1965 Dr. Asimov received the James T. Grady Award of the American Chemical Society for his major contribution in reporting science progress to the public.]