Hermann Muller received the 1946 Nobel Prize in Physiology or Medicine for his work on mutations induced by X-rays. Seymour Benzer used genetics to prove that mutations were caused by changes in the DNA sequence.

HERMANN MULLER (1890-1967)

Hermann Muller was born in Manhattan in 1890 and grew into a 5'2" science geek. His father, who casted statues at Muller Art Metal Works, influenced Hermann with his socialist ideals and a love of science. As a boy, Hermann spent summers hiking in the Adirondack Mountains and spent nights pondering how life would be on the planets he viewed through his telescope.

Upon graduation from Morris High School in 1907 at age sixteen, Muller attended Columbia University and was attracted to the emerging field of genetics.

He remained at Columbia for graduate school where he spent time in T.H. Morgan's Drosophila lab. Muller joined Morgan's other students in stealing small milk bottles from apartment steps to house the flies. But Muller clashed with Morgan and his student, Alfred Sturtevant, because Muller felt that they did not fully acknowledge his ideas in their papers.

Consequently, Muller appears on few papers that came from the Fly Lab except his own. In one paper, Muller showed that mutations in one gene could alter the expression of another gene, implying that many fly characteristics depend on several interacting genes. He left the lab in 1915 after receiving his degree and eventually joined the faculty at the University of Texas.

In the 1920s, Muller performed his Nobel prize-winning research showing that X-rays could induce mutations and he became instantly famous. Muller used his fame to caution against the indiscriminate use of X-rays in medicine, but despite his warnings, some physicians even prescribed X-rays to stimulate ovulation in sterile women. His warnings angered many doctors and were largely ignored.

Muller's outspoken views on socialism also got him in trouble with the Texas administration. He helped publish a Communist newspaper at the school, and the FBI tracked his activities. Feeling that U.S. society was regressing during the Depression, Muller left for Europe in 1932.

A move to the Soviet Union in 1934 seemed to have cured Muller of his Communist sympathies, although he always remained a socialist. Initially happy with the progressive society, he wrote popular articles praising the friendly people and the initiative of collective farm workers. But he grew unhappy as Stalin's police state attacked genetics by pushing Lamarkian ideas of evolution. The state dictated who could work in his lab and questioned him for referring to the work of Germans or Russian emigrés. By the time he left in 1937, several of his students and colleagues had "disappeared" or been shipped to Siberia.

Muller spent eight weeks in Spain helping the International Brigade develop a way to get blood for transfusions from recently killed soldiers, and then worked at the University of Edinburgh where he continued to work on X-rays and other mutagens like UV and mustard gas.

World War II forced Muller to leave Scotland in 1940 and he eventually found a permanent position at Indiana University in 1945. A year later, Muller won the Nobel Prize for his work on mutation-inducing X-rays and he used the opportunity to continue pressing for more public knowledge about the hazards of X-ray radiation.

Throughout his career, Muller felt scientists should get involved in educating the public. Not only was he outspoken about the effects of radiation, he also fought against the Texas school board's attacks on evolution. He promoted his view of eugenics - though he criticized the American eugenics movement for its racism and classism - and recommended voluntary reproduction through artificial insemination for families with genetic disorders.

Muller died in 1967 of congestive heart failure.

SEYMOUR BENZER (1921-2007)

Seymour Benzer was born in 1921 and grew up in the Bensonhurst neighborhood of Brooklyn, NY. His parents emigrated from Warsaw, Poland and worked in the garment industry. Although his family was not interested in science, Benzer dissected flies in his basement lab and read books on atomic physics during synagogue.

At 15, Benzer graduated from high school and studied physics and chemistry at Brooklyn College on a Regents Scholarship. He continued his study of physics in graduate school at Purdue University where he worked on a secret military radar project.

Later in grad school, Benzer read a short book called What is Life?, the same book that turned James Watson from ornithology to his quest for the structure of DNA. Erwin Schrodinger's book had a similar effect on Benzer because it made the mysterious nature of genes sound like the problem to solve. Benzer took the summer bacteriophage course at Cold Spring Harbor Laboratory in 1948 with Gunther Stent. After struggling to learn the course's most important skill - holding a test tube in one hand and the test tube cap and pipette in the other - Benzer was hooked on biology.

Benzer returned to Purdue as a professor of physics, but spent most of his time travelling to other labs to work in molecular biology. In 1953, after Watson and Crick published their model of DNA, Benzer hatched his plan to get inside the gene by using bacteriophage with mutant rII genes. Max Delbrück ridiculed the plan and told Benzer "you must have drunk a triple highball before writing this." Benzer's 5-year-old daughter Martha liked the plan better and sketched her vision of two phages infecting a bacterium. In 1971, Benzer received the Lasker Award for this "brilliant contribution to molecular genetics."

After ten years of work on the rII system, and prompted by observations of his two daughters, Benzer began studying how genes shape behavior. As a professor of biology at Caltech, he and his graduate student Ronald Konopka were the first to find a gene that controls an organism's sense of time. Benzer received the Crafoord Prize in 1993 for his pioneering work in genes and behavior. He won the Albany Medical Center Prize in Medicine and Biomedical Research (2006), which has been called the American Nobel Prize, for demonstrating that single gene mutations in Drosophila can greatly affect behavior.

Benzer worked on genes and aging in fruit flies with support from the Ellison Medical Foundation Senior Scholars in Aging Program. When he was not spending the night working in his lab (he thought he was a clock mutant), he could be seen warming up a lunch of cow's udder or bull testicles on his Bunsen burner, prying open locked doors, and playing with his plastic eyeball keychain.

Benzer suddenly died of a stroke at 86 in November 2007.

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