What Is Life? can be viewed as a well-reasoned theoretical prediction of what biologists should have been looking for during their search for genetic material. Both James D. Watson, and Francis Crick, who jointly proposed the double helix structure of DNA based on X-ray diffraction experiments by Rosalind Franklin, credited Schrödinger's book with presenting an early theoretical description of how the storage of genetic information would work, and each independently acknowledged the book as a source of inspiration for their initial researches. The book is based on lectures delivered under the auspices of the Institute at Trinity College, Dublin, in February 1943 and
History of molecular biology modeling efforts of Watson and Crick. In their modeling, Watson and Crick restricted themselves to what they saw as chemically and biologically reasonable. Still, the breadth of possibilities was very wide. A breakthrough occurred in 1952, when Erwin Chargaff visited Cambridge and inspired Crick with a description of experiments Chargaff had published in 1947. Chargaff had observed that the proportions of the four nucleotides vary between one DNA sample and the next, but that for particular pairs of nucleotides — adenine and thymine, guanine and cytosine — the two nucleotides are always present in equal proportions. Using X-ray diffraction, as