Jannasch, Holger

Harlyn Halvorson and Holger Jannasch were both interested in the origin of life and evolution. Thus, their interests also melded with Esther's interest in life and biochemistry both on the earth and outside the earth, as studied by such people as Aleksandr I. Oparin. This interest was expressed well before the term "exobiology" was coined.¹

¹ See the sample page from Esther's 1946 class notebook on Evolution, in which Oparin's work is explicitly mentioned, as well as her interest in Oparin's visit to NASA Ames Research Center in 1969. Note: Although a major contribution to the field by Joshua Lederberg was the coining of the word "exobiology", Joshua Lederberg's views on contamination have been found to be faulty. As noted by Dr. Eric T. Kool of Stanford University, contamination cannot be limited to living forms, nor even molecules such as DNA and RNA. The depth of the correspondence between Aleksandr I. Oparin and J. Lederberg at its height is rigorously discussed in Oparin correspondence .

² See personal correspondence from Harlyn O. Halvorson to Esther M. Zimmer Lederberg, in this website.