"Evolution as Fact and Theory" first appeared in Discover magazine in May 1981; "Phyletic size decrease in Hershey bars" appeared in C. J. Rubins's Junk Food, 1980; and his "Reply to Critics", was written specifically for this volume as a commentary upon criticism of essay 16, "The Piltdown Conspiracy".
The article "Evolution as Fact and Theory" debuted in Discover magazine in May 1981.  C. J. Rubins's book "Junk Food" featured the paper "Phyletic size decrease in Hershey bars." Additionally, a response to criticism of essay 16, titled "Reply to Critics," was written specifically for this volume and addressed the critique of "The Piltdown Conspiracy".