George Beadle, an Uncommon Farmer: The Emergence of Genetics in the 20th Century

  • Paul Berg &
  • Maxine Singer
Cold Spring Harbor Laboratory Press: 2003. 383 pp. $35, £25
Field work: at Cornell, George Beadle (kneeling) studied maize genetics with Barbara McClintock (right). Credit: CALTECH

Genetics is a young science, having its roots just 100 or so years ago in the rediscovery of Gregor Mendel's work on inheritance in peas. These days, this history is left out of most textbooks and is rarely taught at university. Today's students learn only about what has happened in the past five years, not about the pioneering work that opened up their field — they know nothing of the giants on whose shoulders they stand. If you ask today's advanced genetics students about George Beadle (1903–1989), you would be met with a deafening silence. So it is fortunate that Paul Berg and Maxine Singer took the time to write a book about this great pioneer.

They describe Beadle's family and his childhood and youth on a farm close to Wahoo, Nebraska. His father prevented his elder brother from going to agricultural college, but when this brother died after being kicked by a horse on the farm, George was allowed to go the agricultural college in Lincoln, where he developed an interest in maize genetics. His intelligence and hard work impressed his teachers, who sent him to Cornell University in Ithaca, New York, where he continued to work on maize genetics. There he met Barbara McClintock, who demonstrated that maize has ten chromosomes. But her supervisor was not amused when she published this under her own name without including him as a co-author.

Beadle's work on maize genetics earned him a PhD in 1929, after which he moved to the California Institute of Technology, which was an exciting place to be. Thomas Hunt Morgan had just moved there, and the authors describe his fly group in a separate chapter that is a must for students. I would have liked to hear more. For example, the authors mention that the undergraduate Alfred Sturtevant produced the first linear map of five genes of the fruitfly's X chromosome, and that Morgan allowed him to publish his results without demanding his own name on the paper. Berg and Singer don't comment on this, but how many professors would allow this today?

Beadle started collaborating with Boris Ephrussi, who was on sabbatical there, to try and understand what a gene produces. For Morgan and his group, the gene was abstract, but Beadle and Ephrussi wanted to come closer to biochemistry. They concentrated on Drosophila mutants with different eye colours, vermilion and cinnabar. After five years they concluded that tryptophan is converted by the vermilion gene into a substance of unknown structure. So it was a blow in 1940 when they read in the journal Naturwissenschaften that Adolf Butenandt had identified the compound as 3-hydroxykynurenine. Five years' work and then scooped!

Ephrussi then moved into a different field but Beadle stuck to the problem. During a lecture by his postdoc Edward Tatum, Beadle had the idea of treating microorganisms with mutagens and isolating mutants that are unable to produce amino acids, hormones or other substances. These mutants will then show that one gene produces one enzyme. Tatum did the experiment using the fungus Neurospora. It worked like a charm, and hundreds of such mutants were isolated and analysed. What worked well with Neurospora worked even better with the bacterium Escherichia coli. One of Tatum's students, Joshua Lederberg, showed that such mutants could be isolated, and demonstrated genetic exchange between two mutants of E. coli. In 1958, Beadle, Lederberg and Tatum shared a Nobel prize for their work. As Ephrussi wrote to a friend: “I suddenly felt my life wasted.”

But the story does not end here. When the experimental problem was solved and Beadle had convinced the sceptics, he moved into the field of administration at Caltech, first as chairman of the biological faculty and then as president. He excelled at hiring excellent faculty and defended Linus Pauling when he was attacked as a communist. Even after his retirement, Beadle returned to a familiar problem: was teosinte, a wild grass from Mexico, really the predecessor of maize?

The book tells us in detail about Beadle's two marriages, the salaries he earned (but not their equivalent values today), his journeys by ship and by train, and the fact that he succumbed to Alzheimer's disease. There is plenty here for everyone. Those interested in the history of genetics will want to read the whole book, but today's students would benefit from just a few chapters.