Seymour Benzer (1921–2007)

Biology lost one of its greats with the death on November 30th last year of Seymour Benzer. In the century that began with the rediscovery of Mendelian units of heredity and ended with the sequencing of the human genome, Benzer’s studies of gene fine structure defined the pivotal moment in the transition from classical to molecular genetics. This quiet devoté of science, with an impish sense of humor and a taste for the phylogenetically exotic in food, then went on to found what has become the bustling field of the genetic analysis of behavioral mechanisms. It is rare enough in the history of science for someone to make a discovery as momentous and synthetic as Benzer’s phage findings, let alone to go on afterwards to inaugurate a new approach that grows into a major scientific field. Born in Brooklyn in 1921 to Jewish Polish immigrant parents, he was the first member of the family to go beyond high school. Science was his first love, and it lasted his whole life. He was interested in biology from an early age, but ended up majoring in physics and chemistry at Brooklyn College, because they were more challenging than the taxonomic approach typical of the biology teaching of the day. As a graduate student at Purdue University in the mid-1940s doing research related to the war effort (Figure 1), he discovered the key properties of germanium crystals that eventually made it the element of choice for transistors. He joined the Physics faculty at Purdue in 1947, but soon gravitated back towards biology. While a graduate student, he had read Erwin Schrödinger’s What Is Life? [1], a seminal book which framed the question of what was the physical basis of the gene, and which was so effective in attracting physicists into the nascent field of phage genetics. Obituary If one of the giants of quantum mechanics could speculate seriously that the problem of heredity might reveal new laws of nature, then it must be challenging enough for physicists to tackle. The romantic notion of exploring totally uncharted waters appealed to Benzer then and for the rest of his life. He was undaunted by the fact that many traditional geneticists took a dim view of phage, telling Benzer that if he wanted to study genetics, he should work on a ‘real organism’. Schrödinger’s book highlighted the genetic speculations of Max Delbrück, a young quantum physicist who had been bitten by the genetic bug and taken up investigations of bacteriophage as an ‘elemental’ genetic entity. In 1948, while an assistant professor of Physics at Purdue, Benzer took Delbrück’s summer phage course at Cold Spring Harbor and parted ways with physics research for good. He joined the small international community of scientists known as the ‘phage group’ (led by Max Delbrück and Salvadore Luria and including Alfred Hershey, Leo Szilard, James Watson and Gunther Stent, among others) and spent as much time away from Purdue in various phage labs as he did being a faculty member. Delbrück served this group as founder, organizer, cheerleader, critic and even as scoutmaster for its regular camping trips in the deserts east of Caltech. All of Benzer’s papers from the phage era end with an acknowledgement to Delbrück “for his invaluable moderating influence” (when is the last time you heard of a prominent scientist exerting a moderating influence?). With the dissemination of Watson and Crick’s model for DNA structure in 1953, and its implications for linear coding, Benzer hatched a plan to use classical genetic mapping to define the functional structure of the gene. The discovery of mRNA was still eight years off in the future, and there was no way to define the gene biochemically. So Benzer used a traditional genetic approach to move genetics down to the molecular level. In a 1952 review article, entitled “Genetic Formulation of Gene Structure and Gene Action”, the fungal geneticist Guido Pontecorvo had framed the problem as follows: