PROFILE: George W. Beadle
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George W. Beadle: Nobel Prize-winning biologist initiated revolutionary changes in the study of heredity
Copyright © 2004 by E. A. KralBecoming a nationally significant researcher is uncommon, and receiving a Nobel Prize quite rare. But to achieve both and be credited with changing the direction of an entire field of knowledge for the long-range benefit of humankind is something few in history can claim.
Such were the accomplishments of Wahoo, Nebraska native George W. Beadle, whose career in the branch of biology known as genetics (the scientific study of heredity) and in college administration spanned the middle decades of the 20th century.
Prior to 1941, the year he and his Stanford University colleague Edward Tatum published the first results of their experiment on red bread mold which gave birth to the science of biochemical genetics, knowledge about transmission of hereditary traits from parents to offspring was primarily descriptive.
About 3000 BC, the Greek philosopher Aristotle thought that traits were inherited through the blood, an erroneous idea that endured about 1,000 years. Then in the late 1600s, it was believed that eggs and sperm contained a very small but completely-formed embryo that grew in size in the mother. By the 1800s, it was theorized that traits are passed along from parent to offspring.
The origins of the scientific study of heredity appeared in the 1866 published report by Gregor Mendel, an Augustinian monk at what is now Brno, Czech Republic. He had conducted experiments on garden peas.
Mendel's two principles, according to World Book Encyclopedia, included his finding that hereditary traits are specified by what he called factors. These, he inferred, occur in pairs in each of the cells in offspring and that the factors in each pair separate during the formation of the gametes, or sex cells. His other finding was that each pair of factors is inherited independently of the other pairs.
An important discovery of other scientists by 1900 was the structure and function of a human cell. Each cell contains a nucleus that contains structures called chromosomes, which were considered to be carriers of heredity.
During the early decades of the 20th century, scientists developed useful terminology. In 1909, Danish biologist Wilhelm Johannsen used the term "gene" (which replaced Mendel's term "factors") to describe the element of heredity, and discovered that changes in inheritance were due to mutations.
A theory of "gene action," or the physical basis of heredity, also emerged as a result of work by American scientists. It was suggested that genes were a part of chromosomes, that genes had locations on chromosomes, and that mutation of genes could be introduced by physical agents such as X rays.
But what is a gene and how does it work?
At the time, scientists knew that the basic unit of life is the cell (it carries out life's functions such as growth and reproduction), and in order to perform its work, the cell generates energy from metabolizing foodstuffs and makes proteins (substances made of amino acids) and enzymes (proteins that speed up chemical reactions).
They also know the cell's nucleus (its control center) contains chromosomes, the small thread-like structures on which genes are located. Yet, while they could say there is a gene for brown hair, the gene itself did not possess brown hair and it didn't make brown hair.
So Beadle and Tatum decided to test the idea that a gene could only give instructions (information) for the production of a particular chain of amino acids (proteins) that would then become the specific enzyme (protein) that would enable the production of a certain physical trait.
In their Stanford University Laboratory, they studied the nutritional requirements of a red bread mold in a series of experiments to support or refute their one gene--one enzyme theory.
They irradiated 5,000 spores of red bread mold to see if mutations (changes) produced mutations and altered the organisms' nutritional requirements. The 299th spore required a vitamin for growth that the normal mold cell could make.
Beadle and Tatum's break-through discovery showed that the purpose of the gene is to control a specific chemical reaction. That is, the way the gene operated was by producing or failing to produce an enzyme that made the reaction succeed or fail.
By showing that genes have a physiological role, Beadle and his colleagues caused geneticists to consider genes as units of function. And their strategy of identifying mutants that are affected in one of the steps of a particular biological process offered a new experimental approach.
Thus, while at Stanford University in the early 1940s, Beadle had helped to initiate the science of biochemical genetics. Then from 1946 to 1961, when he was chairman of the biology division at California Institute of Technology at Pasadena, he built what became one of the world's leading centers of molecular, cellular, and developmental biology.
Scientists in England had discovered in 1953 that the chromosomes within the nucleus of each cell in a person's body contains twisted, double strands of material called deoxyribonucleic acid (DNA), a molecule that contains the genetic code,
The work of scientists at Cal Tech and elsewhere eventually led to the discovery that genes are segments of these DNA strands, and Beadle's original one gene--one enzyme theory became modified to the view that a single gene specifies one or more macromolecules.
Geneticists now agree that the function of a gene is to transfer the code of instructions (information) contained in the DNA, and thus direct the cell to produce another chemical, usually a protein, that has a specific task to do, such as determining the coloring of hair.
During Beadle's 15 years as chairman of Cal Tech's biology division, he implemented his vision of merging biochemistry and genetics, and attracted many brilliant minds as professors, researchers, and students.
At one time or another, there were at least 16 who were--or would become--elected to the prestigious National Academy of Sciences for their significant research. Five of them eventually earned Nobel Prizes, including Beadle himself in 1958, Renato Dulbecco in 1975, Edward Lewis in 1995, Roger Sperry in 1981, and James Watson in 1962. (Linus Pauling, Nobel winner in 1954 and 1962, was at Cal Tech before Beadle arrived.)
According to the distinguished biochemists Paul Berg and Maxine Singer, authors of the first book-length biography on Beadle, "the extraordinary advances that emerged from the marriage of biochemistry and biology in the second half of the 20th century affirm Beadle's view. Perhaps the most dramatic evidence is how advances in the chemistry and ease of manipulation of DNA made sequencing of the human and other genomes possible, thereby providing enormously productive new approaches to genetics."
While at Cal Tech, Beadle obtained funds for research and construction needs in his division, received frequent requests for participation in the development of science policy, and was committed to the integrity of science and interests of the universities.
As a consultant to the Atomic Energy Commission, he understood the importance of keeping United States' atomic secrets but had concerns about government procedures on security issues. He was a member of the National Research Council panel that studied genetic effects of atomic radiation, and served as president of the American Association for the Advancement of Science.
From 1961 to 1968, he served as the 7th president of the University of Chicago, where he worked to restore the campus to its previous reputation of intellectual and scholarly eminence, created $70 billion worth of new buildings, attracted some 250 new faculty members, and raised almost $160 million in a major fundraising campaign the final three years of his tenure.
During his retirement years, he investigated the origins of corn, and continued publishing. From 1927 to 1981, he authored or co-authored more than 90 research articles, books, and reviews.
As for honors, Beadle was elected to the National Academy of Sciences in 1944, and received 11 awards, including the Albert Lasker Award in 1950 and the Nobel Prize in 1958 in physiology or medicine, the latter shared with Edward Tatum and Joshua Lederberg.
Granted honorary doctorate degrees from 37 different institutions of higher learning, including the University of Nebraska in 1949, he was also the subject of a July 14, 1958 Time cover story.
His place in history has also been assured with biographical entries in Notable Twentieth-Century Scientists, Vol 1 (Gale, 1995) and American National Biography, Vol 2 (Oxford University Press, 1999).
An interesting, thorough biography that includes his Nebraska years is the book by Paul Berg and Maxine Singer, George Beadle, An Uncommon Farmer: The Emergence of Genetics in the 20th Century (Cold Spring Harbor Laboratory Press, 2003). Berg was recipient of the 1980 Nobel Prize in chemistry and Singer the 1992 National Medal of Science.
Born near Wahoo, Saunders County, Nebraska in 1903, one of three children of Chauncey and Hattie Albro Beadle, George lived on a farm, and attended a rural school. When he was four years of age, his mother died, and when he was eight years of age, his brother died. While attending Wahoo High School, where he graduated in 1922, he was encouraged by his science teacher Bess McDonald to attend college.
Beadle earned his bachelor and master degrees in agronomy from the University of Nebraska-Lincoln in 1926 and 1927, respectively, and received his doctorate in plant genetics from Cornell University at Ithaca, New York in 1931.
From there he conducted research on fruit fly and corn genetics projects at California Institute of Technology, then spent one year in Paris, France with a research colleague, followed by one year as biology professor at Harvard University before relocating in 1937 to Stanford University.
Married twice, Beadle raised one son and a stepson, and remained connected to his Nebraska heritage through his hobby of growing corn in his private gardens, and occasional visits. As late as 1997, Wahoo had displayed at its town entrance a large billboard that featured the names of its most distinguished people: Beadle, C. W. Anderson, Sam Crawford, Howard Hanson, and Darryl Zanuck.
According to the October 6, 1977 Wahoo Newspaper, he and other donors established in honor of his former high school teacher the Bess McDonald Memorial Scholarship in Science Fund with the University of Nebraska Foundation, which has annually awarded a scholarship since the 1980-81 school year to a Wahoo High School graduate attending UNL.
Information about Bess McDonald's career and association with Beadle was published in the September 14 and October 31, 1958 Lincoln Star. In 1989, George W. Beadle died at the age of 85 at Pomona, California. The urn of his cremated remains was placed in the Rockefeller Chapel at the University of Chicago.
The Beadle Center at 19th & Vine on the UNL City Campus, which offers learning experiences in biochemistry, molecular biology, and other subjects related to the life sciences, was dedicated in his memory in 1995.
For more information, consult "900 Famous Nebraskans" on the Internet at www.nsea.org or www.beatricene.com/gagecountymuseum or www.nebpress.com.
