44 The Nature of Biological Diversity 



origin of life, see M. Calvin, Chemical Evolution, Condon Lectures, Oregon 

 State Board of Higher Education, Univ. of Oregon Press, Eugene (1961). 



35. M. Calvin, The chemistry of life. 3. How life originated on the earth and in the 

 world beyond, Chem. Eng. News, 39:96-104 (May 22, 1961). 



36. S. W. Fox, K. Harada, and A. Vegotsky, Thermal polymerization of amino 

 acids and a theory of biochemical origin, Experientia, 15:81-84 (1959). S. W. 

 Fox, How did life begin? Science, 132:200-208 (1960). 



37. J. Oro, Direct synthesis of polypeptides. I. Polymerization of glycine in aqueous 

 ammonia, Arch. Biochem. Biophys., 93:166-171 (1961). 



38. R. Gerschman, Oxygen effects in biological systems, Proc. 21st. Intern. Physiol, 

 and Pharmacol. Congress (1959), pp. 222-226. 



39. D. Shemin, Biosynthesis of porphyrins, Harvey Lectures, 50:258-284 (1954- 

 1955). 



40. J. A. Barltrop, Private communication. 



