Francis Crick's unending dedication to science saw him working to the very end. Credit: M. LIEBERMAN/SALK

Francis Crick, widely regarded as one of the twentieth century's most significant figures in biology, was a scientist to the end. In his hospital bed, just hours before he died on 28 July following a prolonged battle with colon cancer, he was working on a manuscript.

It was a theoretical discussion of the claustrum, a little-studied region of the brain that might play an important role in human consciousness, the object of Crick's academic efforts for nearly 30 years. His unending dedication to his work came as no surprise to friends and colleagues who spoke about him this week.

“He was the living incarnation of what it is to be a scholar,” says Christof Koch, a computational neuroscientist at the California Institute of Technology in Pasadena and a close colleague of Crick's for 16 years. “He was always willing to revise his own views in light of the actions of a Universe that never ceased to astonish him.”

Although Crick's name will forever be connected with the discovery of the double-helix structure of DNA, which he published in 1953 with James Watson (Nature 171, 737–738; 1953), his subsequent contributions to molecular biology and neuroscience have also had a profound impact.

In the 1950s, he helped to prove that sequences of three bases in DNA code for particular amino acids, and described how these could be used to make proteins. Later he was instrumental in decrypting which triplets of bases coded for which amino acids.

By the mid-1970s, Crick's interest in molecular biology had begun to wane. He felt that the important problems had been solved, and that only details remained to be worked out. “He didn't want to work on small problems,” recalls Alexander Rich, a biologist at the Massachusetts Institute of Technology in Cambridge who solved the structure of one of the body's main structural proteins — collagen — with Crick in 1955 (A. Rich and F. H. C. Crick Nature 176, 915–916; 1955).

In 1976, Crick moved to the Salk Institute for Biological Sciences in La Jolla, California, where he would devote the rest of his life to understanding the biological basis of consciousness — a problem many considered too difficult to tackle. “Because of his stature, he made brain science respectable,” says Leslie Orgel, a colleague of Crick's at Salk.

The paper Crick was finishing when he died may influence the direction of Salk's Crick–Jacobs Center for Computational and Theoretical Biology, established earlier this year, says president Richard Murphy. “He thought the claustrum would be a good test system for the centre,” Murphy says. The centre will focus on the genes, proteins and neural networks that make the brain function.

→ http://www.nature.com/nature/focus/crick