"It thus appears possible that there would be no evolution without molecular disease."

Linus Pauling. "Molecular Disease, Evolution and Genic Heterogeneity." Horizons in Biochemistry (Albert Szent-Györgyi Dedicatory Volume), Michael Kasha and Bernard Pullman, eds. New York: Academic Press 1962.

"I cannot imagine what would have happened to me, scientifically, if, in 1957, in a Hotel lobby in Paris, you had refused my request to come and work with you. I know that whatever field I would have been working in would not have been comparable in interest and scope to the one - or, rather, to the several - that you opened up to me."

Emile Zuckerkandl. Letter to Linus Pauling. May 28, 1964.

"[Zuckerkandl] found that in the beta chain of the human and the beta chain of the horse, for example, 20 of the 146 amino acids are different; but with human and gorilla, only one is different. It is the same amount of difference, just one amino acid residue, as between ordinary humans and sickle cell anemia patients, who manufacture sickle-cell-anemia hemoglobin."

Linus Pauling. "Medicine in a Rational Society." J. Mt. Sinai Hosp. N. Y. 36: 194-199. 1969.