Isaac Asimov 
Genetic Effects of Radiation [EPUB ebook] 

Excerpt: "There is nothing new under the sun, says the Bible. Nor is the sun itself new, we might add. As long as life has existed on earth, it has been exposed to radiation from the Sun, SO that life and radiation are Old acquaintances and have learned to live together. We are accustomed to looking upon sunlight as something good, useful, and desirable, and certainly we could not live long without it. The energy of sunlight warms the earth, produces the winds that tend to equalize earth’s temperatures, evaporates the Oceans and produces …"